Processing apparatus, processing method, and processing program

Abstract

To provide a processing device capable of generating sound data that creates a sense of direction by considering diffracted sound without blocking direct sound. [Solution] A processing device comprising: a sound processing unit that generates first sound data which reaches the right ear in a straight line when a first line segment connecting the position of a virtual sound source and the position of the right ear of a listener's head model intersects the head model at only one point, and reaches the right ear by diffracting a part of the head model when the first line segment intersects the head model at two points; a sound processing unit that generates second sound data which reaches the left ear in a straight line when a third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, and reaches the left ear by diffracting a part of the head model when the third line segment intersects the head model at two points; and an output sound data generation unit that generates stereoscopic sound data based on the first sound data and the second sound data.

Description

[Technical Field]

[0001] The present invention relates to an apparatus, a processing method, and a processing program. [Background technology]

[0002] Patent Document 1 discloses a technique that enables adjustment of the sound pressure balance by providing a sound-insulating member to block the sound propagation path connecting the speaker and the listener's ear canal, and causing the diffracted sound generated by the sound-insulating member to arrive in the ear canal at an angle close to the direction connecting both of the listener's ears. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 62-199198 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the technology described in Patent Document 1 requires the installation of a sound-blocking member to block direct sound, which incurs installation costs. [Means for solving the problem]

[0005] One aspect of the apparatus according to the present invention is: A sound processing unit that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, The system includes an output sound data generation unit that generates stereoscopic sound data to be output to multiple sound output devices based on the first sound data and the second sound data, The sound processing unit is If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume of the sound reaching the left ear via the third path and The third delay amount is calculated, The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

[0006] One aspect of the processing method according to the present invention is: A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, The process includes generating output sound data based on the first sound data and the second sound data to generate stereoscopic sound data to be output to multiple sound output devices, In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the left ear is defined as the position of the virtual sound source and the second tangent line between the second tangent line and the head model. The sum of the length of the fourth line segment connecting the point of contact and the length of the second circular arc connecting the second point of contact and the position of the left ear is calculated. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

[0007] One aspect of the processing program according to the present invention is: A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, A computer is instructed to perform an output sound data generation step, which generates stereoscopic sound data to be output to multiple sound output devices based on the first sound data and the second sound data. In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram illustrating the processing apparatus of the first embodiment. [Figure 2] A diagram showing an example configuration of the processing apparatus according to the first embodiment. [Figure 3] A diagram showing an example of the configuration of the sound processing unit. [Figure 4] A diagram illustrating an example of the processing in the distance calculation unit. [Figure 5] A diagram illustrating an example of the processing in the distance calculation unit. [Figure 6] A diagram illustrating an example of the processing in the distance calculation unit. [Figure 7] A diagram illustrating another example of the distance calculation unit's processing. [Figure 8] A diagram illustrating another example of the distance calculation unit's processing. [Figure 9] A diagram illustrating another example of the distance calculation unit's processing. [Figure 10] A flowchart illustrating the procedure for the processing method of the first embodiment. [Figure 11] A flowchart illustrating an example of the steps involved in the distance calculation process shown in Figure 10. [Figure 12] A flowchart illustrating an example of the procedure for the parameter calculation process shown in Figure 10. [Figure 13] A flowchart illustrating an example of the procedure for generating 4-channel audio data, as shown in Figure 10. [Figure 14] A diagram illustrating the processing apparatus of the second embodiment. [Figure 15] A diagram showing an example configuration of the processing apparatus according to the second embodiment. [Figure 16] A diagram illustrating the specific processing steps of the correction processing unit. [Figure 17] A flowchart illustrating the procedure for the processing method of the second embodiment. [Figure 18] A flowchart illustrating an example of the correction process steps in Figure 17. [Figure 19] A diagram illustrating the processing apparatus of the third embodiment. [Figure 20] A diagram showing an example configuration of the processing apparatus according to the third embodiment. [Figure 21] A diagram illustrating head-related transfer functions. [Figure 22] A flowchart illustrating the procedure for the processing method of the third embodiment. [Figure 23] A diagram illustrating the processing apparatus of the fourth embodiment. [Figure 24] A diagram showing an example configuration of the processing apparatus according to the fourth embodiment. [Figure 25] A flowchart illustrating the procedure for the processing method of the fourth embodiment. [Figure 26] A diagram showing an example configuration of the processing apparatus according to the fifth embodiment. [Figure 27] Functional block diagram of the electronic device of this embodiment. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The embodiments described below are not intended to unduly limit the scope of the present invention as described in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0010] 1. Processing device 1-1. First Embodiment 1-1-1. Processing Unit Configuration As shown in Figure 1, the processing device 1 of the first embodiment is connected to four sound output devices 3a, 3b, 3c, and 3d. The sound output devices 3a, 3b, 3c, and 3d are connected to the listening position P, which is the position of the listener U. U They are arranged in concentric circles with the center. The sound output devices 3a, 3b, 3c, and 3d are, for example, speakers. The processing unit 1 outputs stereoscopic sound data that simulates the sound emitted by a virtual sound source VS located at an arbitrary position to the sound output devices 3a, 3b, 3c, and 3d, and generates sounds with different volumes and delays from two or more of the sound output devices 3a, 3b, 3c, and 3d.

[0011] The virtual sound source VS is at the listening position P.U Angle θ relative to this S Listening position P in the direction U Distance d from S It is located at the position shown in Figure 1. When the direction in front of listener U is the positive X-axis, the direction to the right of listener U is the positive Y-axis, and the direction below listener U is the positive Z-axis, the angle θ S This is the clockwise angle when the listener U is viewed in the positive Z-axis direction, with the positive X-axis being 0°. Therefore, for example, angle θ S If the angle is 45°, a virtual sound source VS exists to the right and in front of the listener U, and the angle degree θ S If the angle is -135°, then a virtual sound source VS will be located to the left rear of the listener U.

[0012] Figure 2 shows an example of the configuration of the processing unit of the first embodiment. As shown in Figure 2, the processing unit 1 of the first embodiment outputs sound signals DOa, DOb, DOc, and DOd to ​​sound output devices 3a, 3b, 3c, and 3d, respectively.

[0013] The processing unit 1 comprises a control unit 10, a sound source memory 20, a sound processing unit 30, an output sound data generation unit 40, a storage unit 50, and amplifiers 60a, 60b, 60c, and 60d. The processing unit 1 may be a single-chip semiconductor integrated circuit device, or it may be composed of multiple-chip semiconductor integrated circuit devices, or at least a part of it may be composed of electronic components other than semiconductor integrated circuits. For example, the control unit 10, the sound processing unit 30, the output sound data generation unit 40, and the storage unit 50 may be implemented as a single-chip semiconductor integrated circuit device, while the sound source memory 20 and amplifiers 60a, 60b, 60c, and 60d are provided outside of the semiconductor integrated circuit device. Note that the processing unit 1 may have some of the components in Figure 2 omitted or changed, or other components added. For example, amplifiers 60a, 60b, 60c, and 60d do not have to be components of the processing unit 1.

[0014] The sound source memory 20 stores m monaural sound source data 21-1 to 21-m, where m is an integer greater than or equal to 1. The sound source memory 20 may be, for example, flash memory. Each of the sound source data 21-1 to 21-m may be, for example, pulse code modulated (PCM) audio data or adaptive differential pulse code modulated (ADPCM) audio data. PCM is an abbreviation for Pulse Code Modulation, and ADPCM is an abbreviation for Adaptive differential Pulse Code Modulation. The sound source data 21-1 to 21-m are, for example, data that forms the basis of various sounds such as warning sounds, sound effects, and sounds that mimic human speech.

[0015] The memory unit 50 is composed of RAM, ROM, registers, etc. The RAM is Random ROM stands for Read Only Memory, and Access Memory is an abbreviation for Access Memory. The storage unit 50 may have non-volatile memory.

[0016] The control unit 10 is a circuit that communicates data with the microcontroller unit 2 and controls the operation of each part of the processing unit 1. The control unit 10 may, for example, have an SPI interface circuit or an I2C interface circuit. SPI stands for Serial Peripheral Interface, and I2C stands for Inter-Integrated Circuit.

[0017] The control unit 10 receives various commands transmitted from the micro control unit 2 and generates various control signals according to the received commands. For example, when the control unit 10 receives a data writing command to the storage unit 50, it generates a control signal for writing the data specified at the address specified by the command. Also, for example, when the control unit 10 receives an audio reproduction command for the audio data 21-i among the audio data 21-1 to 21-m stored in the sound source memory 20, it generates a control signal for instructing the audio reproduction for the audio data 21-i. i is an arbitrary integer from 1 to m. Thereby, the audio data 21-i is output from the sound source memory 20 as the sound source data SDI and input to the sound processing unit 30. Note that, if necessary, the sound source data SDI obtained by decoding the audio data 21-i by a decoder not shown may be input to the sound processing unit 30. Also, the processing device 1 may generate the sound source data SDI in real time.

[0018] Based on the monaural sound source data SDI and the position of the virtual sound source VS, the sound processing unit 30 generates four-channel sound data SDFR, SDFL, SDRR, and SDRL. The sound data SDFR of the first channel is the data that is the source of the sound output from the sound output device 3a in front of the right of the listener U. The sound data SDFL of the second channel is the data that is the source of the sound output from the sound output device 3b in front of the left of the listener U. The sound data SDRR of the third channel is the data that is the source of the sound output from the sound output device 3c behind the right of the listener U. The sound data SDRL of the fourth channel is the data that is the source of the sound output from the sound output device 3d behind the left of the listener U. As shown in FIG. 1, the position of the virtual sound source VS is specified by the angle θ and the distance d with respect to the listening position P.

[0019] As shown in FIG. 1, the position of the virtual sound source VS is specified by the angle θ and the distance d with respect to the listening position P. U with respect to the angle θ S and the distance d S The angle θ S and the distance d S are set, for example, based on an instruction from the micro control unit 2 and output from the control unit 10.

[0020] Figure 3 shows an example of the configuration of the sound processing unit 30. As shown in Figure 3, the sound processing unit 30 includes a distance calculation unit 31, a parameter calculation unit 32, and sound data generation units 33a, 33b, 33c, and 33d.

[0021] Figures 4, 5, and 6 illustrate an example of the processing performed by the distance calculation unit 31. In Figures 4, 5, and 6, the same X, Y, and Z axes as in Figure 1 are defined, and the virtual sound source VS is assumed to be located to the right and in front of the listener U.

[0022] As shown in Figures 4, 5, and 6, the head model HM, which is a circular model of the listener U's head, passes through the center point O and is a straight line parallel to the X-axis, which is line L. X Let's draw a line L that passes through the center point O of the head model HM and is parallel to the Y-axis. Y In this case, for example, the position of the right ear of the head model HM corresponding to the position of the listener U's right ear is on the line L Y Two points E where the head model HM intersects R ,E L Point E is located in the positive direction of the Y-axis relative to the center point O. R The position of the left ear of the head model HM, which corresponds to the left ear of listener U, is the same as the two points E. R ,E L Point E is located in the negative direction of the Y-axis relative to the center point O. L It is assumed to be at this position.

[0023] As shown in Figure 4, the distance calculation unit 31 calculates the line segment L connecting the position of the virtual sound source VS and the position of the right ear of the head model HM. VR However, it determines whether the line segment L intersects with the head model HM at one point or two points. Since the virtual sound source VS is located to the right and in front of the listener U, the line segment L VR This is the head model HM and point E R The lines intersect at only one point. In this case, the distance calculation unit 31 calculates the distance d1 of the line segment L as the distance of the first path through which the sound generated by the virtual sound source VS reaches the right ear of the head model HM in a straight line. VR Length d VR Calculate.

[0024] Furthermore, as shown in Figure 5, the distance calculation unit 31 calculates the line segment L connecting the position of the virtual sound source VS and the position of the left ear of the head model HM. VL However, it determines whether the line segment L intersects with the head model HM at one point or two points. Since the virtual sound source VS is located to the right and in front of the listener U, the line segment L VL This is the head model HM and points Q,E L The lines intersect at these two points. In this case, the distance calculation unit 31 calculates the tangent line TL of the head model HM that passes through the position of the virtual sound source VS. FL The distance calculation unit 31 then calculates the position of the virtual sound source VS and the tangent line TL. FL Contact point C between the head model HM and the head model HM FL Line segment L connecting to FL Length d FL and contact C FL Arc A connecting the left ear position of the head model HM to the arc A. FL Length a FL The calculation unit 31 further calculates the distance d4 of the fourth path through which the sound generated by the virtual sound source VS diffracts a part of the head model HM and reaches the left ear, and the line segment L FL Length d FL and arc A FL Length a FL Calculate the sum with arc A. FL This is the arc of the frontal region of the head model HM, which corresponds to the frontal region of the listener U. Therefore, the fourth path is the path through which the sound generated by the virtual sound source VS diffracts through the frontal region of the head model HM and reaches the left ear.

[0025] Also, as shown in Figure 6, line segment L VL This is the head model HM and points Q,E L Since they intersect at these two points, the distance calculation unit 31 calculates the tangent line TL of the head model HM that passes through the position of the virtual sound source VS. RL The distance calculation unit 31 then calculates the position of the virtual sound source VS and the tangent line TL. RL and head model Contact point C with HM RL Line segment L connecting to RL Length d RL and contact C RL Arc A connecting the left ear position of the head model HM to the arc A. RL Length a RLThe calculation unit 31 further calculates the distance d6 of the sixth path through which the sound generated by the virtual sound source VS diffracts a part of the head model HM and reaches the left ear, and the line segment L RL Length d RL and arc A RL Length a RL Calculate the sum with arc A. RL This is the arc of the occipital region of the head model HM, which corresponds to the occipital region of the listener U. Therefore, the sixth path is the path through which the sound generated by the virtual sound source VS diffracts through the occipital region of the head model HM and reaches the left ear.

[0026] Figures 7, 8, and 9 illustrate another example of the processing of the distance calculation unit 31. In Figures 7, 8, and 9, the same X, Y, and Z axes as in Figure 1 are defined, and the virtual sound source VS is assumed to be located to the left and in front of the listener U.

[0027] As shown in Figure 7, the distance calculation unit 31 calculates the line segment L connecting the position of the virtual sound source VS and the position of the right ear of the head model HM. VR However, it determines whether the line segment L intersects with the head model HM at one point or two points. Since the virtual sound source VS is located to the left and in front of the listener U, the line segment L VR This is the head model HM and points Q,E R The lines intersect at these two points. In this case, the distance calculation unit 31 calculates the tangent line TL of the head model HM that passes through the position of the virtual sound source VS. FR The distance calculation unit 31 then calculates the position of the virtual sound source VS and the tangent line TL. FR Contact point C between the head model HM and the head model HM FR Line segment L connecting to FR Length d FR and contact C FR Arc A connecting the right ear position of the head model HM. FR Length a FR The calculation unit 31 calculates the distance d2 of the second path through which the sound generated by the virtual sound source VS diffracts a part of the head model HM and reaches the right ear, and the line segment L FR Length d FR and arc A FR Length a FR Calculate the sum with arc A. FRis the arc of the forehead of the head model HM. Therefore, the second path is the path through which the sound generated by the virtual sound source VS diffracts around the forehead of the head model HM and reaches the right ear.

[0028] Also, as shown in FIG. 8, the line segment L VR intersects the head model HM at two points Q and E R . Therefore, the distance calculation unit 31 calculates the tangent TL RR of the head model HM passing through the position of the virtual sound source VS. Then, the distance calculation unit 31 calculates the length d RR of the line segment L RR connecting the position of the virtual sound source VS and the contact point C RR between the tangent TL RR and the head model HM, and the length a RR of the arc A RR connecting the contact point C RR and the position of the right ear of the head model HM. Further, the distance calculation unit 31 calculates, as the distance d5 of the fifth path through which the sound generated by the virtual sound source VS diffracts around a part of the head model HM and reaches the right ear, the sum of the length d RR of the line segment L RR and the length a RR of the arc A RR . The arc A RR is the arc of the back of the head of the head model HM. Therefore, the fifth path is the path through which the sound generated by the virtual sound source VS diffracts around the back of the head of the head model HM and reaches the right ear.

[0029] Also, as shown in FIG. 9, the distance calculation unit 31 determines whether the line segment L VL connecting the position of the virtual sound source VS and the position of the left ear of the head model HM intersects the head model HM at one point or two points. Since the virtual sound source VS is in front of the left of the listener U, the line segment L VL intersects the head model HM at only one point E L . In this case, the distance calculation unit 31 calculates, as the distance d3 of the third path through which the sound generated by the virtual sound source VS reaches the left ear of the head model HM linearly, the length d VL of the line segment L The VL is calculated.

[0030] Note that the distance calculation unit 31 is the line segment LVR When the line segment L intersects the head model HM at only one point, the distance d2 of the second path, the distance d5 of the fifth path, the arc A FR with length a FR and the arc A RR with length a RR are both set to zero. Also, when the line segment L VR intersects the head model HM at two points, the distance d1 of the first path is set to zero. Also, when the line segment L VL intersects the head model HM at only one point, the distance d3 of the third path, the distance d6 of the sixth path, the arc A FL with length a FL and the arc A RL with length a RL are both set to zero. Also, when the line segment L VL intersects the head model HM at two points, the distance d3 of the third path is set to zero.

[0031] Returning to the description of FIG. 3, the parameter calculation unit 32 calculates the volume VL FR , a FL , a RR , a RL with respect to the sound data SDFR of the first channel based on the distances d1 to d6 and the arc lengths a FR , the delay amount DL FR and the cut-off frequency FC FR , the volume VL FL with respect to the sound data SDFL of the second channel, the delay amount DL FL and the cut-off frequency FC FL , the volume VL RR with respect to the sound data SDRR of the first channel, the delay amount DL RR and the cut-off frequency FC RR , the volume VL RL with respect to the sound data SDRL of the second channel, the delay amount DL RL and the cut-off frequency FC RL and calculates them.

[0032] Specifically, the parameter calculation unit 32 calculates the volume VL1 and delay DL1 of the sound reaching the right ear of the head model HM via the first path, based on the distance d1 of the first path, if the distance d1 of the first path is not zero. For example, the parameter calculation unit 32 can calculate the volume VL1 by applying the distance d1 of the first path to the volume attenuation characteristics, and calculate the delay DL1 by dividing the distance d1 of the first path by the speed of sound. The longer the distance d1 of the first path, the smaller the volume VL1 and the larger the delay DL1.

[0033] If the virtual sound source VS is located to the right front, the first path is the path by which the sound generated by the virtual sound source VS reaches the right ear of the head model HM in a straight line from the front. If the virtual sound source VS is located to the right rear, the first path is the path by which the sound generated by the virtual sound source VS reaches the right ear of the head model HM in a straight line from the rear. Therefore, the parameter calculation unit 32 calculates the angle θ of the virtual sound source VS if the distance d1 of the first path is not zero. S Based on this, it is determined whether the virtual sound source VS is located to the front right or to the rear right.

[0034] If the virtual sound source VS is located to the right and in front, the parameter calculation unit 32 calculates the volume VL1 and delay amount DL1 respectively. FR and delay amount DL FR The output is as follows. The parameter calculation unit 32 also calculates the cutoff frequency FC so that all frequencies of sound generated by the virtual sound source VS reach the right ear of the head model HM via the first path. FR For example, set this to ∞. On the other hand, if the virtual sound source VS is located to the right rear, the parameter calculation unit 32 sets the volume VL1 and delay amount DL1 respectively to volume VL RR , delay amount DL RR The output is as follows. The parameter calculation unit 32 also calculates the cutoff frequency FC so that all frequencies of sound generated by the virtual sound source VS reach the right ear of the head model HM via the first path. RR Set it to, for example, ∞.

[0035] Furthermore, if the distance d2 of the second path is not zero, the parameter calculation unit 32 calculates the volume VL2 and delay amount DL2 of the sound reaching the right ear of the head model HM via the second path, based on the distance d2 of the second path. For example, the parameter calculation unit 32 can calculate the volume VL2 by applying the distance d2 of the second path to the volume attenuation characteristics, and calculate the delay amount DL2 by dividing the distance d2 of the second path by the speed of sound. The longer the distance d2 of the second path, the smaller the volume VL2 and the larger the delay amount DL2. Also, the parameter calculation unit 32 calculates the arc A FR Length a FR Based on this, the cutoff frequency FC2 for the sound reaching the right ear of the head model HM via the second path is calculated. Higher-pitched sounds are less prone to diffraction, so arc A FR Length a FR The larger the value, the lower the cutoff frequency FC2 becomes. The parameter calculation unit 32 then calculates the volume VL2, delay amount DL2, and cutoff frequency FC2, respectively. FR , delay amount DL FR and cutoff frequency FC FR Output as follows.

[0036] Furthermore, if the distance d5 of the fifth path is not zero, the parameter calculation unit 32 calculates the volume VL5 and delay amount DL5 of the sound reaching the right ear of the head model HM via the fifth path, based on the distance d5 of the fifth path. For example, the parameter calculation unit 32 can calculate the volume VL5 by applying the distance d5 of the fifth path to the volume attenuation characteristics, and calculate the delay amount DL5 by dividing the distance d5 of the fifth path by the speed of sound. The longer the distance d5 of the fifth path, the longer the volume VL5. As it gets smaller, the delay amount DL5 gets larger. Also, the parameter calculation unit 32 calculates the arc A RR Length a RR Based on this, the cutoff frequency FC5 for the sound reaching the right ear of the head model HM via the fifth path is calculated. Higher-pitched sounds are less prone to diffraction, so arc A RR Length a RR The larger the value, the lower the cutoff frequency FC5 becomes. The parameter calculation unit 32 then calculates the volume VL5, delay amount DL5, and cutoff frequency FC5, respectively.RR , delay amount DL RR and cutoff frequency FC RR Output as follows.

[0037] Furthermore, if the distance d3 of the third path is not zero, the parameter calculation unit 32 calculates the volume VL3 and delay DL3 of the sound reaching the left ear of the head model HM via the third path, based on the distance d3 of the third path. For example, the parameter calculation unit 32 can calculate the volume VL3 by applying the distance d3 of the third path to the volume attenuation characteristics, and calculate the delay DL3 by dividing the distance d3 of the third path by the speed of sound. The longer the distance d3 of the third path, the smaller the volume VL3 and the larger the delay DL3.

[0038] If the virtual sound source VS is located to the left front, the third path is the path through which the sound generated by the virtual sound source VS reaches the left ear of the head model HM in a straight line from the front. If the virtual sound source VS is located to the left rear, the third path is the path through which the sound generated by the virtual sound source VS reaches the left ear of the head model HM in a straight line from the rear. Therefore, if the distance d3 of the third path is not zero, the parameter calculation unit 32 calculates the angle θ of the virtual sound source VS. S Based on this, it is determined whether the virtual sound source VS is located to the front left or to the rear left.

[0039] If the virtual sound source VS is located to the left front, the parameter calculation unit 32 calculates the volume VL3 and delay amount DL3 respectively. FL and delay amount DL FL The output is as follows. The parameter calculation unit 32 also calculates the cutoff frequency FC so that all frequencies of sound generated by the virtual sound source VS reach the left ear of the head model HM via the third path. FL For example, set this to ∞. On the other hand, if the virtual sound source VS is located to the left rear, the parameter calculation unit 32 sets the volume VL3 and delay amount DL3 to volume VL3, respectively. RL , delay amount DL RL The output is as follows. The parameter calculation unit 32 also calculates the cutoff frequency FC so that all frequencies of sound generated by the virtual sound source VS reach the right ear of the head model HM via the third path. RLSet it to, for example, ∞.

[0040] Furthermore, if the distance d4 of the fourth path is not zero, the parameter calculation unit 32 calculates the volume VL4 and delay DL4 of the sound reaching the left ear of the head model HM via the second path, based on the distance d4 of the fourth path. For example, the parameter calculation unit 32 can calculate the volume VL4 by applying the distance d4 of the fourth path to the volume attenuation characteristics, and calculate the delay DL4 by dividing the distance d4 of the fourth path by the speed of sound. The longer the distance d4 of the fourth path, the smaller the volume VL4 and the larger the delay DL4. Also, the parameter calculation unit 32 calculates the arc A FL Length a FL Based on this, the cutoff frequency FC4 for the sound reaching the left ear of the head model HM via the fourth path is calculated. Higher-pitched sounds are less prone to diffraction, so arc A FL Length a FL The larger the value, the lower the cutoff frequency FC4 becomes. The parameter calculation unit 32 then calculates the volume VL4, delay amount DL4, and cutoff frequency FC4, respectively. FL , delay amount DL FL and cutoff frequency FC FL Output as follows.

[0041] Furthermore, if the distance d6 of the sixth path is not zero, the parameter calculation unit 32 calculates the volume VL6 and delay amount DL6 of the sound reaching the left ear of the head model HM via the sixth path, based on the distance d6 of the sixth path. For example, the parameter calculation unit 32 can calculate the volume VL6 by applying the distance d6 of the sixth path to the volume attenuation characteristics, and calculate the delay amount DL6 by dividing the distance d6 of the sixth path by the speed of sound. The longer the distance d6 of the sixth path, the smaller the volume VL6 and the larger the delay amount DL6. Also, the parameter calculation unit 32 calculates the arc A RL Length a RL Based on this, the cutoff frequency FC6 for the sound reaching the left ear of the head model HM via the sixth path is calculated. Higher-pitched sounds are less prone to diffraction, so arc A RL Length a RL but The larger the value, the lower the cutoff frequency FC6 becomes. The parameter calculation unit 32 then calculates the volume VL6, delay amount DL6, and cutoff frequency FC6, respectively. RL , delay amount DL RL and cutoff frequency FC RL Output as follows.

[0042] The sound data generation unit 33a receives sound source data SDI and volume VL FR , delay amount DL FR and cutoff frequency FC FR Based on this, the first channel audio data SDFR is generated. The audio data generation unit 33a includes a volume setting unit 34a and a delay amount setting unit 35a. The volume setting unit 34a sets the volume VL to the audio source data SDI. FR The delay amount setting unit 35a sets the delay amount DL to the sound source data SDI. FR The volume VL is set to the sound source data SDI. FR and delay amount DL FR The audio data SDFR is generated by setting the following. The audio data generation unit 33a may also include a low-pass filter 36a. The low-pass filter 36a has a cutoff frequency FC relative to the audio source data SDI. FR The low-pass filter processing is performed on the sound source data SDI. That is, the sound data generation unit 33a applies volume VL to the sound source data SDI. FR and delay amount DL FR Set the cutoff frequency FC. FR You may also generate sound data SDFR by performing a low-pass filter process.

[0043] The sound data generation unit 33b receives sound source data SDI and volume VL FL , delay amount DL FL and cutoff frequency FC FL Based on this, the second channel audio data SDFL is generated. The audio data generation unit 33b includes a volume setting unit 34b and a delay amount setting unit 35b. The volume setting unit 34b sets the volume VL to the audio source data SDI. FL The delay amount setting unit 35b sets the delay amount DL to the sound source data SDI. FLThis is set. In other words, the sound data generation unit 33b sets the volume VL to sound source data SDI. FL and delay amount DL FL The audio data SDFL is generated by setting the following. The audio data generation unit 33b may also include a low-pass filter 36b. The low-pass filter 36b has a cutoff frequency FC relative to the audio source data SDI. FL The low-pass filter processing is performed on the sound source data SDI. That is, the sound data generation unit 33b processes the volume VL FL and delay amount DL FL Set the cutoff frequency FC. FL You may also generate the audio data SDFL by performing a low-pass filter process.

[0044] The sound data generation unit 33c receives sound source data SDI and volume VL RR , delay amount DL RR and cutoff frequency FC RR Based on this, the third channel audio data SDRR is generated. The audio data generation unit 33c includes a volume setting unit 34c and a delay amount setting unit 35c. The volume setting unit 34c sets the volume VL to the audio source data SDI. RR The delay amount setting unit 35c sets the delay amount DL to the audio source data SDI. RR This is set. In other words, the sound data generation unit 33c sets the volume VL to sound source data SDI. RR and delay amount DL RR The sound data SDRR is generated by setting the following. The sound data generation unit 33c may also include a low-pass filter 36c. The low-pass filter 36c has a cutoff frequency FC relative to the sound source data SDI. RR The low-pass filter processing is performed on the sound data SDI. That is, the sound data generation unit 33c processes the volume VL RR and delay amount DL RR Set the cutoff frequency FC. RR You may also generate the sound data SDRR by performing a low-pass filter process.

[0045] The sound data generation unit 33d receives sound source data SDI and volume VL RL , delay amount DL RLand cutoff frequency FC RL Based on this, the fourth channel audio data SDRL is generated. The audio data generation unit 33d includes a volume setting unit 34d and a delay amount setting unit 35d. The volume setting unit 34d sets the volume VL to the audio source data SDI. RL The delay amount setting unit 35d sets the delay amount DL to the audio source data SDI. RL This is set. In other words, the sound data generation unit 33d sets the volume VL to sound source data SDI. RL and delay amount DL RL The audio data SDRL is generated by setting the following. The audio data generation unit 33d may also include a low-pass filter 36d. The low-pass filter 36d has a cutoff frequency FC relative to the audio source data SDI. RL The low-pass filter processing is performed on the sound source data SDI. That is, the sound data generation unit 33d applies volume VL to the sound source data SDI. RL and delay amount DL RL Set the cutoff frequency FC. RL Low-pass fill You may perform a processing step to generate the sound data SDRL.

[0046] The sound processing unit 30 configured in this way is for line segment L VR If the signal intersects with the head model HM at only one point, based on the position of the virtual sound source VS, the sound data reaching the right ear of the head model HM via the first path is output as either the first channel sound data SDFR or the third channel sound data SDRR, and silent data is output as the other of the first channel sound data SDFR or the third channel sound data SDRR.

[0047] Furthermore, the sound processing unit 30 controls the line segment L VR When the signal intersects with the head model HM at two points, the sound data reaching the right ear of the head model HM via the second path is output as the first channel sound data SDFR, and the sound data reaching the right ear of the head model HM via the fifth path is output as the third channel sound data SDRR.

[0048] Furthermore, the sound processing unit 30 controls the line segment L VLIf the signal intersects with the head model HM at only one point, based on the position of the virtual sound source VS, the sound data reaching the left ear of the head model HM via the third path is output as either the second channel sound data SDFL or the fourth channel sound data SDRL, and silent data is output as the other of the second channel sound data SDFL or the fourth channel sound data SDRL.

[0049] Furthermore, the sound processing unit 30 controls the line segment L VL When the signal intersects with the head model HM at two points, the sound data reaching the left ear of the head model HM via the fourth path is output as the second channel sound data SDFL, and the sound data reaching the left ear of the head model HM via the sixth path is output as the fourth channel sound data SDRL.

[0050] If the virtual sound source VS is located to the right and in front of the listener U, then line segment L VR It intersects with the head model HM at only one point, and line segment L VL The line intersects with the head model HM at two points. In this case, the first channel sound data SDFR is data simulating sound reaching the listener U's right ear in a straight line, the second channel sound data SDFL is data simulating sound diffracting through the listener U's forehead and reaching the left ear, the third channel sound data SDRR is silent data, and the fourth channel sound data SDRL is data simulating sound diffracting through the listener U's occipital region and reaching the left ear.

[0051] Even if the virtual sound source VS is located to the right and behind the listener U, line segment L VR It intersects with the head model HM at only one point, and line segment L VL The line intersects with the head model HM at two points. In this case, the first channel sound data SDFR is silent data, the second channel sound data SDFL is data simulating sound diffracting through the frontal lobe of listener U and reaching the left ear, the third channel sound data SDRR is data simulating sound reaching the right ear of listener U in a straight line, and the fourth channel sound data SDRL is data simulating sound diffracting through the occipital lobe of listener U and reaching the left ear.

[0052] Furthermore, if the virtual sound source VS is located to the left and in front of the listener U, then line segment L VR The line intersects the head model HM at two points, and line segment L VL The signal intersects with the head model HM at only one point. In this case, the first channel sound data SDFR simulates sound diffracting through the listener U's forehead and reaching the right ear, the second channel sound data SDFL simulates sound reaching the listener U's left ear in a straight line, the third channel sound data SDRR simulates sound diffracting through the listener U's occipital region and reaching the right ear, and the fourth channel sound data SDRL is silent data.

[0053] Even if the virtual sound source VS is located to the left rear of the listener U, line segment L VR The line intersects the head model HM at two points, and line segment L VL It intersects with the head model HM at only one point. In this case, the first channel Nell's sound data SDFR simulates sound that diffracts through the frontal lobe of listener U and reaches the right ear, the second channel sound data SDFL is silent data, the third channel sound data SDRR simulates sound that diffracts through the occipital lobe of listener U and reaches the right ear, and the fourth channel sound data SDRL simulates sound that reaches the left ear of listener U in a straight line.

[0054] Furthermore, if the virtual sound source VS is located in front of the listener U, then line segment L VR and line segment L VL Both lines intersect the head model HM at two points. In this case, the first channel sound data SDFR simulates the sound that diffracts through the frontal lobe of listener U and reaches the right ear, the second channel sound data SDFL simulates the sound that diffracts through the frontal lobe of listener U and reaches the left ear, the third channel sound data SDRR simulates the sound that diffracts through the occipital lobe of listener U and reaches the right ear, and the fourth channel sound data SDRL simulates the sound that diffracts through the occipital lobe of listener U and reaches the left ear.

[0055] Returning to the explanation of Figure 2, the output sound data generation unit 40 generates sound data DOFR, DOFL, DORR, and DORL as stereo sound data to be output to the sound output devices 3a, 3b, 3c, and 3d, based on the 4-channel sound data SDFR, SDFL, SDRR, and SDRL generated by the sound processing unit 30.

[0056] As shown in Figure 2, in this embodiment, the output sound data generation unit 40 includes crosstalk cancellers 41a and 41b.

[0057] The crosstalk canceller 41a performs a process to reduce crosstalk between the first channel sound data SDFR and the second channel sound data SDFL based on the placement information 51 of the sound output devices 3a, 3b, 3c, and 3d. Various known techniques can be applied to the process of reducing crosstalk between the sound data SDFR and the sound data SDFL. The placement information 51 is, for example, the listening position P. U This information pertains to the angle and distance of the respective positions of the sound output devices 3a, 3b, 3c, and 3d relative to the listening position P, and is stored in the storage unit 50 beforehand. U If the listening position P changes, the microcontroller unit 2 will detect the listening position P of the sensor (not shown). U Based on this, placement information 51 may be generated and transmitted to the control unit 10, or the microcontrol unit 2 may be at listening position P U The information is transmitted to the control unit 10, and the control unit 10 determines the listening position P U The placement information 51 may be updated accordingly. The sound data SDFR and SDFL, with reduced crosstalk, are input to amplifiers 60a and 60b as sound data DOFR and DOFL, respectively.

[0058] The crosstalk canceller 41b performs a process to reduce crosstalk between the third channel audio data SDRR and the fourth channel audio data SDRL based on the placement information 51. Various known techniques can be applied to the process of reducing crosstalk between the audio data SDRR and the audio data SDRL. The audio data SDRR and SDRL with reduced crosstalk are input to amplifiers 60c and 60d as audio data DORR and DORL, respectively.

[0059] Amplifier 60a converts sound data DOFR into sound signal DOa and outputs it to sound output device 3a. Amplifier 60b converts sound data DOFL into sound signal DOb and outputs it to sound output device 3b. Amplifier 60c converts sound data DORR into sound signal DOc and outputs it to sound output device 3c. Amplifier 60d converts sound data DORL into sound signal DOd and outputs it to sound output device 3d. As a result, sounds corresponding to sound signals DOa, DOb, DOc, and DOd are output from sound output devices 3a, 3b, 3c, and 3d, respectively. The sounds output from each of the sound output devices 3a, 3b, 3c, and 3d may be various sounds such as warning sounds or sound effects, or they may be voices that mimic human speech.

[0060] In Figure 2, the sound source data 21-1 to 21-m are stored in the sound source memory 20 inside the processing unit 1, but they may also be stored in the external memory of the processing unit 1. Alternatively, the sound source data 21-1 to 21-m may be stored in the memory built into the microcontroller unit 2, and the microcontroller unit 2 may send the sound source data SDI along with the audio playback command to the processing unit 1.

[0061] Note that line segment L VR This is an example of a "first line segment," and line segment L FR This is an example of a "second line segment," and line segment L VL This is an example of a "third line segment," and line segment L FL This is an example of a "fourth line segment," and line segment L RR This is an example of a "fifth line segment," and line segment L RL This is an example of the "sixth line segment". Tangent line TL FRThis is an example of a "first tangent," and tangent TL FL This is an example of a "second tangent," and tangent TL RR This is an example of a "third tangent," and tangent TL RL This is an example of a "fourth tangent." Point C FR This is an example of a "first contact," and contact C FL This is an example of a "second contact," and contact C RR This is an example of a "third contact," and contact C RL This is an example of a "fourth point of contact". Arc A FR This is an example of the "first arc," and arc A FL This is an example of a "second arc," and arc A RR This is an example of the "third arc," and arc A RL This is an example of the "fourth arc". Volume VL1 is an example of the "first volume", volume VL2 is an example of the "second volume", volume VL3 is an example of the "third volume", volume VL4 is an example of the "fourth volume", volume VL5 is an example of the "fifth volume", and volume VL6 is an example of the "sixth volume". Delay amount DL1 is an example of the "first delay amount", delay amount DL2 is an example of the "second delay amount", delay amount DL3 is an example of the "third delay amount", delay amount DL4 is an example of the "fourth delay amount", delay amount DL5 is an example of the "fifth delay amount", and delay amount DL6 is an example of the "sixth delay amount". Cutoff frequency FC2 is an example of the "first cutoff frequency", and cutoff frequency FC4 is an example of the "second cutoff frequency". The sound data reaching the right ear of the head model HM via the first path is an example of "first sound data," and the sound data reaching the right ear of the head model HM via the second path is another example of "first sound data." The sound data reaching the left ear of the head model HM via the third path is an example of "second sound data," and the sound data reaching the left ear of the head model HM via the fourth path is another example of "second sound data." The sound data reaching the right ear of the head model HM via the fifth path is an example of "third sound data," and the sound data reaching the right ear of the head model HM via the sixth path is an example of "fourth sound data." Crosstalk canceller 41a is an example of "first crosstalk canceller," and crosstalk canceller 41b is an example of "second crosstalk canceller."

[0062] 1-1-2. Procedure for Processing Figure 10 is a flowchart showing the procedure of the processing method of the first embodiment. The processing method of the first embodiment is performed by the processing device 1 of the first embodiment shown in Figure 2.

[0063] As shown in Figure 10, first, in the sound processing step S1, the processing unit 1 generates four-channel sound data SDFR, SDFL, SDRR, and SDRL based on the position of the monaural sound source data SDI and the virtual sound source VS. The sound processing step S1 is performed by the sound processing unit 30 of the processing unit 1. In this embodiment, the sound processing step S1 includes a distance calculation step S10, a parameter calculation step S20, and a four-channel sound data generation step S30.

[0064] First, in the distance calculation step S10, the processing unit 1 calculates the aforementioned distances d1 to d6 and the arc length a based on the position of the virtual sound source VS and the head model HM which models the listener U's head as a circle. FR ,a FL ,a RR ,a RL The distance is calculated. The distance calculation step S10 is performed by the distance calculation unit 31 of the sound processing unit 30. The specific procedure for the distance calculation step S10 will be described later.

[0065] Next, in the parameter calculation step S20, the processing unit 1 calculates the distances d1 to d6 and the arc length a calculated in step S10. FR ,a FL ,a RR ,a RL And the angle θ of the virtual sound source VS S Based on the above, the volume VL FR ,VL FL ,VL RR ,VL RL , delay amount DL FR DL FL DL RR DL RL and cutoff frequency FC FR FC FL FC RR FC RLCalculate it. The parameter calculation step S20 is executed by the parameter calculation unit 32 of the sound processing unit 30. The specific procedure of the parameter calculation step S20 will be described later.

[0066] Then, in the 4-channel sound data generation step S30, the processing device 1 adjusts the volume VL calculated in step S20 for the sound source data SDI FR , VL FL , VL RR , VL RL , the delay amount DL FR , DL FL , DL RR , DL RL and the cut-off frequency FC FR , FC FL , FC RR , FC RL are set to generate 4-channel sound data SDFR, SDFL, SDRR, SDRL. The 4-channel sound data generation step S30 is executed by the sound data generation units 33a, 33b, 33c, 33d of the sound processing unit 30. The specific procedure of the 4-channel sound data generation step S30 will be described later.

[0067] As shown in FIG. 10, next, in the output sound data generation step S2, the processing device 1 generates stereophonic sound data to be output to the sound output devices 3a, 3b, 3c, 3d based on the 4-channel sound data SDFR, SDFL, SDRR, SDRL generated in the sound processing step S1. The output sound data generation step S2 is executed by the output sound data generation unit 40 of the processing device 1. In the present embodiment, the output sound data generation step S2 includes a first crosstalk cancellation step S40 and a second crosstalk cancellation step S50.

[0068] First, in the first crosstalk cancellation step S40, the processing device 1 generates sound data DOFR, DOFL with reduced crosstalk between the sound data SDFR of the first channel and the sound data SDFL of the second channel. The first crosstalk cancellation step S40 is executed by the crosstalker 41a of the output sound data generation unit 40.

[0069] Also, in the second crosstalk cancellation step S50, the processing device 1 generates sound data DORR and DORL with reduced crosstalk between the sound data SDRR of the third channel and the sound data SDRL of the fourth channel. The second crosstalk cancellation step S50 is executed by the crosstalker 41b of the output sound data generation unit 40.

[0070] FIG. 11 is a flowchart showing an example of the procedure of the distance calculation step S10 in FIG. 10. As shown in FIG. 11, first, in step S101, the processing device 1 generates a head model HM that models the head of the listener U as a circle. For example, the radius of the head model HM may be a fixed value such as 0.09 m, or a value input by the listener U may be set, or a value measured by a sensor for the head of the listener U may be set.

[0071] Next, in step S102, the processing device 1 calculates a line segment L that connects the position of the virtual sound source VS and the position of the right ear of the head model HM. VR to calculate.

[0072] Next, in step S103, the processing device 1 determines whether the line segment L VR intersects the head model HM at one point or two points. In step S103, when the line segment L VR intersects the head model HM at one point, in step S104, the processing device 1 uses the length d of the line segment L VR as the distance d1 of the first path where the sound generated by the virtual sound source VS reaches the right ear of the head model HM linearly. VR to calculate.

[0073] Also, in step S103, when the line segment L VR intersects the head model HM at two points, first, in step S105, the processing device 1 calculates a tangent line TL of the head model HM passing through the position of the virtual sound source VS. FR Next, in step S106, the processing device 1 uses the distance d2 of the second path where the sound generated by the virtual sound source VS diffracts through the forehead of the head model HM and reaches the right ear and Then, the position of the virtual sound source VS and the tangent TL FR Contact C FR Line segment L connecting to FR Length d FR and contact C FR Arc A connecting the right ear position of the head model HM. FR Length a FR The sum of the following is calculated. Next, in step S107, the processing unit 1 calculates the tangent TL of the head model HM passing through the position of the virtual sound source VS. RR Next, in step S108, the processing unit 1 calculates the distance d5 of the fifth path through which the sound generated by the virtual sound source VS diffracts through the back of the head model HM and reaches the right ear, and the position of the virtual sound source VS and the tangent TL. RR Contact C RR Line segment L connecting to RR Length d RR and contact C RR Arc A connecting the right ear position of the head model HM. RR Length a RR Calculate the sum of the two.

[0074] Next, in step S109, the processing unit 1 connects the position of the virtual sound source VS to the position of the left ear of the head model HM with a line segment L. VL Calculate.

[0075] Next, in step S110, the processing apparatus 1 processes the line segment L VL It is determined whether the line segment L intersects the head model HM at one point or at two points. In process S110, line segment L VL When the line intersects with the head model HM at one point, in step S111, the processing device 1 defines the line segment L as the distance d3 of the third path through which the sound generated by the virtual sound source VS reaches the left ear of the head model HM in a straight line. VL Length d VL Calculate.

[0076] Furthermore, in process S110, line segment L VL If the line intersects the head model HM at two points, first, in step S112, the processing device 1 measures the tangent line TL of the head model HM passing through the position of the virtual sound source VS. FLNext, in step S113, the processing unit 1 calculates the distance d4 of the fourth path through which the sound generated by the virtual sound source VS diffracts through the frontal lobe of the head model HM and reaches the left ear, using the position of the virtual sound source VS and the tangent TL. FL Contact C FL Line segment L connecting to FL Length d FL and contact C FL Arc A connecting the left ear position of the head model HM to the arc A. FL Length a FL The sum of the following is calculated. Next, in step S114, the processing unit 1 calculates the tangent TL of the head model HM passing through the position of the virtual sound source VS. RL Next, in step S115, the processing unit 1 calculates the distance d6 of the sixth path through which the sound generated by the virtual sound source VS diffracts through the back of the head model HM and reaches the left ear, and the position of the virtual sound source VS and the tangent TL. RL Contact C RL Line segment L connecting to RL Length d RL and contact C RL Arc A connecting the left ear position of the head model HM to the arc A. RL Length a RL Calculate the sum of the two.

[0077] Furthermore, the processing device 1 controls the line segment L VR If it intersects with the head model HM at one point, the distance of the second path is d2, the distance of the fifth path is d5, and the arc A FR Length a FR and arc A RR Length a RR Both are set to zero. Also, the processing device 1 processes the line segment L VR If the line segment L intersects with the head model HM at two points, the distance d1 of the first path is set to zero. Furthermore, the processing unit 1 processes the line segment L VL If it intersects with the head model HM at one point, the distance of the third path is d3, the distance of the sixth path is d6, and the arc A FL Length a FL and arc A RL Length a RL Both are set to zero. Also, the processing device 1 processes the line segment L VL If the third path intersects with the head model HM at two points, the distance d3 of the third path is set to zero.

[0078] Figure 12 is a flowchart showing an example of the procedure for the parameter calculation process S20 in Figure 10. As shown in Figure 12, first, in process S201, if the distance d1 of the first path is not zero, in process S202, the processing unit 1 calculates the volume VL1 and delay amount DL1 based on the distance d1.

[0079] Then, in step S203, the angle θ of the virtual sound source VS S If the angle is between -90° and less than 90°, that is, if the virtual sound source VS is located to the right and in front of the listener U, then in step S204, the processing unit 1 controls the volume VL FR and delay amount DL FR Set the volume VL1 and delay amount DL1 respectively, and the cutoff frequency FC FR Set to ∞. Also, the processing unit 1, for example, the volume VL RR , delay amount DL RR and cutoff frequency FC RR Set it to zero.

[0080] Furthermore, in process S203, the angle θ of the virtual sound source VS S If the angle is not between -90° and 90°, that is, if the virtual sound source VS is located to the right and behind the listener U, then in step S205, the processing unit 1 controls the volume VL RR and delay amount DL RR Set the volume VL1 and delay amount DL1 respectively, and the cutoff frequency FC RR Set to ∞. Also, the processing unit 1, for example, the volume VL FR , delay amount DL FR and cutoff frequency FC FR Set it to zero.

[0081] Furthermore, if the distance d1 of the first path is zero in process S201, the processing unit 1 will not perform the processes S202 to S205.

[0082] Next, in step S206, if the distance d2 of the second path is not zero and the distance d2 of the fifth path is not zero, in step S207, the processing unit 1 calculates the volume VL2 and delay amount DL2 based on the distance d2. Also, in step S208, the processing unit 1 calculates the arc A FR Length distance a FR Based on this, the cutoff frequency FC2 is calculated. Also in step S209, the processing unit 1 calculates the volume VL5 and delay amount DL5 based on the distance d5. Also in step S210, the processing unit 1 calculates the arc A RR Length distance a RR Based on this, the cutoff frequency FC5 is calculated. Then, in step S211, the processing device 1 calculates the volume VL FR , delay amount DL FR and cutoff frequency FC FR Set volume VL2, delay amount DL2, and cutoff frequency FC2 respectively, and volume VL RR , delay amount DL RR and cutoff frequency FC RR Set the volume (VL5), delay amount (DL5), and cutoff frequency (FC5) respectively.

[0083] Furthermore, if the distance d2 of the second path or the distance d5 of the fifth path is zero in step S206, the processing device 1 will not perform the processing in steps S207 to S211.

[0084] Next, in step S212, if the distance d3 of the third path is not zero, in step S213, the processing unit 1 calculates the volume VL3 and delay amount DL3 based on the distance d3.

[0085] Then, in step S214, the angle θ of the virtual sound source VS S If the angle is between -90° and less than 90°, that is, if the virtual sound source VS is located to the left and in front of the listener U, then in step S215, the processing unit 1 controls the volume VL FL and delay amount DL FL Set the volume VL3 and delay amount DL3 respectively, and the cutoff frequency FC FLSet to ∞. Also, the processing unit 1, for example, the volume VL RL , delay amount DL RL and cutoff frequency FC RL Set it to zero.

[0086] Furthermore, in step S214, the angle θ of the virtual sound source VS S If the angle is not between -90° and 90°, that is, if the virtual sound source VS is located to the left rear of the listener U, then in step S216, the processing unit 1 sets the volume VL RL and delay amount DL RL Set the volume VL3 and delay amount DL3 respectively, and the cutoff frequency FC RL Set to ∞. Also, the processing unit 1, for example, the volume VL FL , delay amount DL FL and cutoff frequency FC FL Set it to zero.

[0087] Furthermore, if the distance d3 of the first path is zero in step S212, the processing unit 1 will not perform the processing in steps S213 to S216.

[0088] Next, in step S217, if the distance d4 of the fourth path is not zero and the distance d6 of the sixth path is not zero, then in step S218, the processing unit 1 calculates the volume VL4 and delay amount DL4 based on the distance d4. Also, in step S219, the processing unit 1 calculates the arc A FL Length distance a FL The cutoff frequency FC4 is calculated based on this. Also, process S In step 220, the processing unit 1 calculates the volume VL6 and delay amount DL6 based on the distance d6. Also, in step S221, the processing unit 1 processes the arc A RL Length distance a RL Based on this, the cutoff frequency FC6 is calculated. Then, in step S222, the processing device 1 calculates the volume VL FL , delay amount DL FL and cutoff frequency FC FL Set volume VL4, delay amount DL4, and cutoff frequency FC4 respectively, and volume VL RL, delay amount DL RL and cutoff frequency FC RL Set the volume VL6, delay amount DL6, and cutoff frequency FC6, respectively.

[0089] In step S217, if the distance d4 of the fourth path is zero or the distance d6 of the sixth path is zero, the processing device 1 does not perform the processing of steps S218 to S222.

[0090] FIG. 13 is a flowchart showing an example of the procedure of the 4-channel sound data generation step S30 in FIG. 10. As shown in FIG. 13, first, in step S301, the processing device 1 sets the volume VL FR and delay amount DL FR for the sound source data SDI, and performs low-pass filter processing with the cutoff frequency FC FR to generate the sound data SDFR of the first channel.

[0091] Next, in step S302, the processing device 1 sets the volume VL FL and delay amount DL FL for the sound source data SDI, and performs low-pass filter processing with the cutoff frequency FC FL to generate the sound data SDFL of the second channel.

[0092] Next, in step S303, the processing device 1 sets the volume VL RR and delay amount DL RR for the sound source data SDI, and performs low-pass filter processing with the cutoff frequency FC RR to generate the sound data SDRR of the third channel.

[0093] Finally, in step S304, the processing device 1 sets the volume VL RL and delay amount DL RL for the sound source data SDI, and performs low-pass filter processing with the cutoff frequency FC RL to generate the sound data SDFL of the fourth channel.

[0094] 1-1-3. Effects As described above, in the processing apparatus 1 of the first embodiment, the sound processing apparatus 30 generates sound data SDFR or sound data SDRR with volume VL1 and delay DL1 corresponding to the sound reaching the right ear of the listener U via the first path, if the first path through which the sound generated by the virtual sound source VS reaches the right ear of the listener U in a straight line is not obstructed by the head of the listener U. If the first path is obstructed by the head of the listener U, it generates sound data SDFR with volume VL2 and delay DL2 corresponding to the sound reaching the right ear via the second path that diffracts through the forehead of the listener U, and sound data SDRR with volume VL5 and delay DL5 corresponding to the sound reaching the right ear via the fifth path that diffracts through the back of the head of the listener U. Furthermore, the sound processing unit 30 generates sound data SDFL or sound data SDRL with volume VL3 and delay DL3 corresponding to the sound reaching the left ear of the listener U via the third path, which is a linear path of sound generated by the virtual sound source VS, if the third path is not obstructed by the head of the listener U. If the third path is obstructed by the head of the listener U, it generates sound data SDFL with volume VL4 and delay DL4 corresponding to the sound reaching the left ear via the fourth path which diffracts through the forehead of the listener U, and sound data SDRL with volume VL6 and delay DL6 corresponding to the sound reaching the left ear via the sixth path which diffracts through the back of the listener U. Therefore, according to the processing unit 1 of the first embodiment, it is possible to generate 4-channel sound data SDFR, SDFL, SDRR, and SDRL that create a sense of direction considering diffracted sound passing through the forehead and back of the listener U, without blocking the direct sound that reaches the left and right ears of the listener U from the virtual sound source VS. Furthermore, according to the processing device 1 of the first embodiment, the changes in sound characteristics from the virtual sound source VS to the left and right ears of the listener U are calculated taking into account not only the volume but also the delay, and four sound output devices 3a, 3b, 3c, and 3d with different volumes and delays are output. Because it can generate sounds, listener U can obtain a more accurate sense of sound direction.

[0095] Furthermore, in the processing device 1 of the first embodiment, if the first path is blocked by the head of the listener U, the sound processing device 30 generates sound data SDFR by setting a cutoff frequency FC2 that attenuates the high-frequency component of the sound according to the distance over which the sound reaching the right ear of the listener U diffracts through the forehead, and generates sound data SDRR by setting a cutoff frequency FC5 that attenuates the high-frequency component of the sound according to the distance over which the sound reaching the right ear of the listener U diffracts through the back of the head. Furthermore, if the third path is blocked by the head of the listener U, the sound processing device 30 generates sound data SDFL by setting a cutoff frequency FC4 that attenuates the high-frequency component of the sound according to the distance over which the sound reaching the left ear of the listener U diffracts through the forehead, and generates sound data SDRL by setting a cutoff frequency FC5 that attenuates the high-frequency component of the sound according to the distance over which the sound reaching the left ear of the listener U diffracts through the back of the head. Therefore, according to the processing device 1 of the first embodiment, the attenuation amount of high-frequency sounds that are less likely to diffract around the frontal and occipital regions of the listener U can be adjusted according to the diffraction distance, so that the listener U can obtain a more accurate sense of sound direction.

[0096] Furthermore, according to the processing device 1 of the first embodiment, crosstalk between the sound reaching the listener U's right ear and the sound reaching the left ear is reduced, allowing the listener U to obtain a more accurate sense of sound direction. In addition, four channels of sound data, SDFR, SDFL, SDRR, and SDRL, corresponding to sounds generated at positions further away from the listener U than the sound output devices 3a, 3b, 3c, and 3d, can also be generated.

[0097] 1-2. Second Embodiment In the following description of the processing apparatus 1 of the second embodiment, the same reference numerals are used for components similar to those in the first embodiment, and descriptions similar to those in the first embodiment are omitted or simplified. The main focus will be on the differences from the first embodiment.

[0098] As shown in Figure 14, the processing device 1 of the second embodiment is connected to four sound output devices 3a, 3b, 3c, and 3d, similar to the first embodiment, but the sound output devices 3a, 3b, 3c, and 3d are connected to the listening position P UThey are not arranged in concentric circles centered on P. On the other hand, the sound processing unit 30 of the processing unit 1 has sound output devices 3a, 3b, 3c, and 3d at the listening position P. U Assuming they are arranged in concentric circles around the center, the volume and delay amounts of the four audio data SDFR, SDFL, SDRR, and SDRL are set. Therefore, the processing device 1 of the second embodiment sets the listening position P U The volume and delay of the sound data SDFR, SDFL, SDRR, and SDRL are corrected according to the distance between the sound output devices 3a, 3b, 3c, and 3d, respectively.

[0099] Figure 15 shows an example of the configuration of the processing device 1 of the second embodiment. As shown in Figure 15, the processing device 1 of the second embodiment differs from the processing device 1 of the first embodiment shown in Figure 2 in that the output sound data generation unit 40 includes a correction processing unit 42.

[0100] Based on the arrangement information 51 of the sound output devices 3a, 3b, 3c, and 3d, the correction processing unit 42 corrects the volume and delay of the four-channel sound data SDFR, SDFL, SDRR, and SDRL output from the sound processing unit 30, and generates the four-channel sound data SDFRX, SDFLX, SDRRX, and SDRLX.

[0101] Figure 16 is a diagram illustrating the specific processing of the correction processing unit 42. As shown in Figure 16, the correction processing unit 42 first determines the listening position P based on the placement information 51. U The distance r from the sound output devices 3a, 3b, 3c, and 3d. a ,r b ,r c ,r d Next, the correction processing unit 42 obtains the distance r a ,r b ,r c ,r d The maximum distance r max distance r a ,r b ,r c ,r d Depending on the ratio to each of the following, the delay amount DL of the audio data SDFR, SDFL, SDRR, and SDRL is determined. FR DLFL DL RR DL RL Correct the following. Figure 16 In the example, the distance r d The maximum distance r max Therefore, for example, the correction processing unit 42 determines the delay amount DL of the sound data SDFR. FR Compare r d / r a The delay amount of the audio data SDFL is adjusted accordingly to increase it. FL Compare r d / r b The adjustment is made to increase the delay amount of the audio data SDRR DL accordingly. RR Compare r d / r c The delay amount of the audio data SDRL is corrected to increase accordingly. RL You may also correct it to 1x.

[0102] Furthermore, the correction processing unit 42 adjusts the distance r a ,r b ,r c ,r d The maximum distance r max distance r a ,r b ,r c ,r d Depending on the ratio with each of the following, the volume VL of each of the sound data SDFR, SDFL, SDRR, and SDRL FR ,VL FL ,VL RR ,VL RL Correct the distance. In the example in Figure 16, the distance d The maximum distance r max Therefore, for example, the correction processing unit 42 adjusts the volume VL of the sound data SDFR. FR Compare r d / r a The volume of the audio data SDFL is adjusted to decrease accordingly. FL Compare r d / r b The volume VL of the sound data SDRR is corrected accordingly to reduce it. RR Compare r d / r c The volume VL of the sound data SDRL is corrected accordingly to reduce it. RL You may also correct it to 1x.

[0103] The correction processing unit 42 then outputs the corrected audio data SDFR, SDFL, SDRR, SDRL as audio data SDFRX, SDFLX, SDRRX, SDRLX, with corrected delay and volume. With this correction, it is as if the audio output devices 3a, 3b, 3c, and 3d are at the listening position P. U Since each sound is output as if it were arranged in concentric circles around a central point, the listener U can perceive the sound as being emitted from a virtual sound source VS.

[0104] The correction processing unit 42 adjusts the delay amount DL of each of the sound data SDFR, SDFL, SDRR, and SDRL. FR DL FL DL RR DL RL It is not easy to correct in the direction of reducing. Therefore, the correction processing unit 42 adjusts the listening position P U The distance d from the furthest sound output device. max Based on the delay amount DL FR DL FL DL RR DL RL It is preferable to correct in the direction of increasing the volume VL of each of the sound data SDFR, SDFL, SDRR, SDRL. FR ,VL FL ,VL RR ,VL RL It is easy to correct in either the direction of decreasing or increasing the value. Therefore, the correction processing unit 42 adjusts the listening position P U The distance d from the furthest sound output device. max Based on volume VL FR ,VL FL ,VL RR ,VL RL You can also correct it in a way that reduces it, or at listening position P U The distance d from the nearest sound output device. min Based on volume VL FR ,VL FL ,VL RR ,VL RL You may also adjust it in a way that increases it.

[0105] Returning to the explanation of Figure 15, the crosstalk canceller 41a performs a process to reduce crosstalk between the first channel sound data SDFRX and the second channel sound data SDFLX output from the correction processing unit 42, based on the placement information 51. The sound data SDFR and SDFL, with reduced crosstalk, are input to amplifiers 60a and 60b as sound data DOFR and DOFL, respectively.

[0106] The crosstalk canceller 41b performs a process to reduce crosstalk between the third channel sound data SDRR and the fourth channel sound data SDRL, which are output from the correction processing unit 42 based on the placement information 51. The sound data SDRR and SDRL with reduced crosstalk are input to amplifiers 60c and 60d as sound data DORR and DORL, respectively.

[0107] The other configurations and functions of the second embodiment of the processing apparatus 1 shown in Figure 15 are the same as those of the first embodiment of the processing apparatus 1 shown in Figure 2, so their description will be omitted.

[0108] Figure 17 is a flowchart illustrating the procedure of the processing method of the second embodiment. The processing method of the second embodiment is performed by the processing device 1 of the second embodiment shown in Figure 15. Figure 17 As shown, first, in the sound processing step S1, the processing unit 1 generates four-channel sound data SDFR, SDFL, SDRR, and SDRL based on the position of the monaural sound source data SDI and the virtual sound source VS. The sound processing step S1 is performed by the sound processing unit 30 of the processing unit 1. In the second embodiment, similar to the first embodiment, the sound processing step S1 includes a distance calculation step S10, a parameter calculation step S20, and a four-channel sound data generation step S30.

[0109] The distance calculation process S10 is the same as the distance calculation process S10 in Figure 10, and its specific procedure is the same as the procedure in Figure 11, so its illustration and explanation are omitted. The distance calculation process S10 is performed by the distance calculation unit 31 of the sound processing unit 30.

[0110] Furthermore, the parameter calculation process S20 is the same as the parameter calculation process S20 in Figure 10, and its specific procedure is the same as the procedure in Figure 12, so its illustration and explanation are omitted. The parameter calculation process S20 is performed by the parameter calculation unit 32 of the sound processing unit 30.

[0111] Furthermore, the processing of the 4-channel sound data generation process S30 is the same as the processing of the 4-channel sound data generation process S30 in Figure 10, and its specific procedure is the same as the procedure in Figure 13, so its illustration and explanation are omitted. The 4-channel sound data generation process S30 is performed by the sound data generation units 33a, 33b, 33c, and 33d of the sound processing unit 30.

[0112] As shown in Figure 17, in the output sound data generation step S2, the processing unit 1 generates stereoscopic sound data to be output to the sound output devices 3a, 3b, 3c, and 3d based on the four-channel sound data SDFR, SDFL, SDRR, and SDRL generated in the sound processing step S1. The output sound data generation step S2 is performed by the output sound data generation unit 40 of the processing unit 1. In the second embodiment, the output sound data generation step S2 includes a correction processing step S32, a first crosstalk cancellation step S40, and a second crosstalk cancellation step S50.

[0113] First, in the correction processing step S32, the processing unit 1 corrects the volume and delay amount of the four-channel sound data SDFR, SDFL, SDRR, and SDRL generated in the sound processing step S1 based on the arrangement information 51, and generates four-channel sound data SDFRX, SDFLX, SDRRX, and SDRLX. The correction processing step S32 is performed by the correction processing unit 42 of the output sound data generation unit 40. The specific procedure of the correction processing step S32 will be described later.

[0114] Next, in the first crosstalk cancellation step S40, the processing unit 1 generates sound data DOFR and DOFL with reduced crosstalk between the first channel sound data SDFRX and the second channel sound data SDFLX. The first crosstalk cancellation step S40 is performed by the crosstalk canceller 41a of the output sound data generation unit 40.

[0115] Furthermore, in the second crosstalk cancellation step S50, the processing unit 1 generates sound data DORR and DORL with reduced crosstalk between the third channel sound data SDRRX and the fourth channel sound data SDRLX. The second crosstalk cancellation step S50 is performed by the crosstalk canceller 41b of the output sound data generation unit 40.

[0116] Figure 18 is a flowchart showing an example of the procedure for the correction processing step S32 in Figure 17. As shown in Figure 18, first, in step S321, the processing device 1 determines the listening position P based on the arrangement information 51 of the sound output devices 3a, 3b, 3c, and 3d. U The distance r from the sound output devices 3a, 3b, 3c, and 3d. a ,r b ,r c ,r d Next, in step S322, the processing device 1 obtains the distance r a ,r b ,r c ,r d The maximum distance r max distance r a ,r b ,r c ,r d The delay amounts of the four audio data SDFR, SDFL, SDRR, and SDRL are corrected according to the ratio of each of the following. In addition, in step S323, the processing unit 1 , maximum distance r max distance r a ,r b ,r c ,r d The respective ratios or distances r a ,r b ,r c ,rd The minimum distance r min distance r a ,r b ,r c ,r d The volume of the four audio data SDFR, SDFL, SDRR, and SDRL is corrected according to their respective ratios. Finally, in step S324, the processing unit 1 converts the four audio data SDFR, SDFL, SDRR, and SDRL, whose delay and volume have been corrected in steps S322 and S323, into four audio data SDFRX, SDFLX, SDRRX, and SDRLX.

[0117] According to the processing device 1 of the second embodiment described above, by correcting the volume and delay amount of the four-channel sound data SDFR, SDFL, SDRR, and SDRL, each of the sound output devices 3a, 3b, 3c, and 3d can generate sound with an appropriate volume and delay amount according to its position, so that the listener U can obtain a more accurate sense of sound direction. In addition, the processing device 1 of the second embodiment can obtain the same effects as the processing device 1 of the first embodiment.

[0118] 1-3. Third Embodiment Hereinafter, with respect to the processing apparatus 1 of the third embodiment, the same reference numerals will be used for components similar to those in the first or second embodiment, and descriptions similar to those in the first or second embodiment will be omitted or simplified. The description will mainly focus on the differences from the first and second embodiments.

[0119] As shown in Figure 19, the processing device 1 of the third embodiment is connected to two sound output devices 3a and 3b. The sound output devices 3a and 3b are connected to the listening position P, which is the position of the listener U. UThey are positioned at an equidistant distance from each other. The sound output devices 3a and 3b are, for example, speakers. The processing unit 1 outputs stereoscopic sound data that simulates the sound emitted by a virtual sound source VS located at an arbitrary position to the sound output devices 3a and 3b, and the sound output devices 3a and 3b generate sounds with different volumes and delays. Thus, while the processing unit 1 of the first or second embodiment is connected to four sound output devices 3a, 3b, 3c, and 3d, the processing unit 1 of the third embodiment differs in that it is connected to two sound output devices 3a and 3b.

[0120] Figure 20 shows an example of the configuration of the processing device 1 of the third embodiment. As shown in Figure 20, the processing device 1 of the third embodiment differs from the processing device 1 of the first embodiment shown in Figure 2 in that it does not include amplifiers 60c and 60d and the configuration of the output sound data generation unit 40.

[0121] As shown in Figure 20, the output sound data generation unit 40 generates right sound data DOR and left sound data DOL as stereo sound data to be output to the sound output devices 3a and 3b, based on the four-channel sound data SDFR, SDFL, SDRR, and SDRL generated by the sound processing unit 30.

[0122] In this embodiment, the output sound data generation unit 40 includes filter processing units 43a, 43b, adder units 44a, 44b, and a crosstalk canceller 45.

[0123] The filter processing unit 43a applies a filter to the first channel sound data SDFR and the second channel sound data SDFL output from the sound processing unit 30 to enhance the sense of direction of sound, generating sound data DOFR and DOFL. This filter processing makes it easier for the listener U to perceive that the sound corresponding to the sound data DOFR and DOFL is coming from the front.

[0124] The filter processing unit 43b applies a filter to the third channel sound data SDRR and the fourth channel sound data SDRL output from the sound processing unit 30 to emphasize the directionality of the sound, generating the sound data DORR and DORL. This filter processing makes it easier for the listener U to perceive the sound corresponding to the sound data DORR and DORL as coming from behind.

[0125] Sound reaching the left and right ears from behind the listener U is attenuated more significantly by the earlobes than sound reaching the left and right ears from in front of the listener U. Therefore, the filtering by the filter processing unit 43b may be a low-pass filter that attenuates high-frequency sounds more significantly than the filtering by the filter processing unit 43a. Alternatively, the filtering by the filter processing unit 43a may apply head-related transfer functions to the sound reaching the left and right ears of the listener U from sound output devices 3a and 3b, respectively, which are positioned in front of the listener U, and the filtering by the filter processing unit 43b may apply head-related transfer functions to the sound reaching the left and right ears of the listener U from sound output devices 3c and 3d, respectively, which are virtually positioned behind the listener U.

[0126] Figure 21 is a diagram illustrating the head transfer function. As shown in Figure 21, the head transfer function h R ( a ) is listening position P U Angle φ a This shows the frequency characteristics of the sound generated by the sound output device 3a located at position , as it reaches the right ear of the listener U. Head-related transfer function h L ( b The head-related transfer function h represents the frequency characteristics of the sound generated by the sound output device 3b until it reaches the left ear of the listener U. R ( c ) is virtually the listening position P U Angle φ c This represents the frequency characteristics of the sound generated by the sound output device 3c located at position φ until it reaches the right ear of the listener U. For example, φ c =180°-φ aThis is also acceptable. Head transfer function h L ( d ) represents the frequency characteristics of the sound generated by the sound output device 3d until it reaches the left ear of the listener U. For example, φ d =180°+(360°-φ b ) is also acceptable.

[0127] For example, sounds from behind listener U are blocked by the ear, causing a significant attenuation of high-frequency components, while sounds from the front are either emphasized or weakened in specific frequency bands depending on the shape of listener U's ear. (Head-related transfer function h) R ( a ),h L ( b ),h R ( c ),h L ( d ) is a transfer function that represents these characteristics.

[0128] Based on the arrangement information 51, the filter processing unit 43a applies a head-related transfer function h to the first channel's sound data SDFR as a filter. R ( a Applying this to generate the audio data DOFR, the head-related transfer function h is applied as a filter to the second channel audio data SDFL. L ( b The audio data DOFL may be generated by applying the following. Based on the placement information 51, the filter processing unit 43b applies the head transfer function h as a filter to the audio data SDRR of the third channel. R ( c Applying this to generate the sound data DORR, the head-related transfer function h is applied as a filter to the fourth channel sound data SDRL. L ( d You may also generate the sound data DORL by applying ).

[0129] The sound output devices 3a and 3b may be positioned behind the listener U. In this case, the filtering by the filter processing unit 43a may apply head-related transfer functions to the sounds reaching each of the listener U's left and right ears from the sound output devices 3c and 3d, which are virtually positioned in front of the listener U, and the filtering by the filter processing unit 43b may apply head-related transfer functions to the sounds reaching each of the listener U's left and right ears from the sound output devices 3a and 3b, which are positioned behind the listener U.

[0130] Returning to the explanation of Figure 20, the adder 44a adds the first channel sound data DOFR output from the filter processing unit 43a and the third channel sound data DORR output from the filter processing unit 43b to output the right sound data DORX. The adder 44b adds the second channel sound data DOFL output from the filter processing unit 43a and the fourth channel sound data DORL output from the filter processing unit 43b to output the left sound data DOLX.

[0131] The crosstalk canceller 45, based on the arrangement information 51 of the sound output devices 3a and 3b, A process is performed to reduce crosstalk between the right-hand audio data DORX output from the summing unit 44a and the left-hand audio data DOLX output from the summing unit 44b. Various known techniques can be applied to reduce crosstalk between the right-hand audio data DORX and the left-hand audio data DOLX. The right-hand audio data DORX and left-hand audio data DOLX, with reduced crosstalk, are input to amplifiers 60a and 60b as the right-hand audio data DOR and the left-hand audio data DOL, respectively.

[0132] Amplifier 60a converts the right sound data DOR into a sound signal DOa and outputs it to sound output device 3a. Amplifier 60b converts the left sound data DOL into a sound signal DOb and outputs it to sound output device 3b. As a result, sounds corresponding to sound signals DOa and DOb are output from sound output devices 3a and 3b, respectively. The sounds output from each of the sound output devices 3a and 3b may be various sounds such as warning sounds or sound effects, or they may be voices that mimic human speech.

[0133] Note that the filter processing unit 43a is an example of a "first filter processing unit," and the filtering process performed by the filter processing unit 43a is an example of a "first filtering process." The filter processing unit 43b is an example of a "second filter processing unit," and the filtering process performed by the filter processing unit 43b is an example of a "second filtering process." The adder 44a is an example of a "first adder," and the adder 44b is an example of a "second adder."

[0134] The other configurations and functions of the third embodiment of the processing apparatus 1 shown in Figure 20 are the same as those of the first embodiment of the processing apparatus 1 shown in Figure 2, so their description will be omitted.

[0135] Figure 22 is a flowchart showing the procedure of the processing method of the third embodiment. The processing method of the third embodiment is performed by the processing device 1 of the third embodiment shown in Figure 20. As shown in Figure 22, first, in the sound processing step S1, the processing device 1 generates four-channel sound data SDFR, SDFL, SDRR, and SDRL based on the position of the monaural sound source data SDI and the virtual sound source VS. The sound processing step S1 is performed by the sound processing unit 30 of the processing device 1. In the third embodiment, similar to the first embodiment, the sound processing step S1 includes a distance calculation step S10, a parameter calculation step S20, and a four-channel sound data generation step S30.

[0136] The distance calculation process S10 is the same as the distance calculation process S10 in Figure 10, and its specific procedure is the same as the procedure in Figure 11, so its illustration and explanation are omitted. The distance calculation process S10 is performed by the distance calculation unit 31 of the sound processing unit 30.

[0137] Furthermore, the parameter calculation process S20 is the same as the parameter calculation process S20 in Figure 10, and its specific procedure is the same as the procedure in Figure 12, so its illustration and explanation are omitted. The parameter calculation process S20 is performed by the parameter calculation unit 32 of the sound processing unit 30.

[0138] Furthermore, the processing of the 4-channel sound data generation process S30 is the same as the processing of the 4-channel sound data generation process S30 in Figure 10, and its specific procedure is the same as the procedure in Figure 13, so its illustration and explanation are omitted. The 4-channel sound data generation process S30 is performed by the sound data generation units 33a, 33b, 33c, and 33d of the sound processing unit 30.

[0139] As shown in Figure 22, in the output sound data generation step S2, the processing unit 1 generates stereoscopic sound data to be output to the sound output devices 3a and 3b based on the four-channel sound data SDFR, SDFL, SDRR, and SDRL generated in the sound processing step S1. The output sound data generation step S2 is performed by the output sound data generation unit 40 of the processing unit 1. In the third embodiment, the output sound data generation step S2 includes a first filter processing step S60, a second filter processing step S62, a first addition step S70, a second addition step S72, and a crosstalk cancellation step S80.

[0140] First, in the first filtering step S60, the processing unit 1 performs a filtering process on the first channel sound data SDFR and the second channel sound data SDFL generated in the sound processing step S1 to emphasize the directional nature of the sound, thereby generating sound data DOFR and DOFL. The first filtering step S60 is performed by the filter processing unit 43a of the output sound data generation unit 40.

[0141] Furthermore, in the second filtering step S62, the processing device 1 performs filtering on the third channel sound data SDRR and the fourth channel sound data SDRL generated in the sound processing step S1 to emphasize the directional nature of the sound, thereby generating the sound data DORR and DORL. The second filtering step S62 is performed by the filter processing unit 43b of the output sound data generation unit 40.

[0142] Next, in the first addition step S70, the processing unit 1 adds the first channel sound data DOFR generated in the first filtering step S60 and the third channel sound data DORR generated in the second filtering step S62 to generate the right sound data DORX. The first addition step S70 is performed by the adder 44a of the output sound data generation unit 40.

[0143] Furthermore, in the second addition step S72, the processing unit 1 adds the second channel sound data DOFL generated in the first filtering step S60 and the fourth channel sound data DORL generated in the second filtering step S62 to generate the left sound data DOLX. The second addition step S72 is performed by the adder 44b of the output sound data generation unit 40.

[0144] Finally, in the crosstalk cancellation process S80, the processing unit 1 generates right-sound data DOR and left-sound data DOL, which reduce the crosstalk between the right-sound data DORX generated in the first addition process S70 and the left-sound data DOLX generated in the second addition process S72. The crosstalk cancellation process S80 is performed by the crosstalk canceller 45 of the output sound data generation unit 40.

[0145] According to the processing device 1 of the third embodiment described above, right sound data DOR and left sound data DOL, which emphasize the sense of direction of sound, can be generated from two sound output devices 3a and 3b, respectively. Therefore, even without four sound output devices 3a, 3b, 3c, and 3d as in the first embodiment, the listener U can obtain a more accurate sense of sound direction. In addition, the processing device 1 of the third embodiment provides the same effects as the processing device 1 of the first embodiment.

[0146] 1-4. Fourth Embodiment Hereinafter, regarding the processing apparatus 1 of the fourth embodiment, the same reference numerals will be used for components similar to those in any of the first to third embodiments, and descriptions similar to those in any of the first to third embodiments will be omitted or simplified. The description will mainly focus on aspects that differ from any of the first to third embodiments.

[0147] As shown in Figure 23, the processing unit 1 of the fourth embodiment is connected to headphones 4 equipped with two sound output devices 3a and 3b. The sound output devices 3a and 3b are, for example, speakers built into the headphones 4. When the listener U is wearing the headphones 4, sound output device 3a is located near the listener U's right ear, and sound output device 3b is located near the listener U's left ear. The processing unit 1 outputs stereoscopic sound data simulating the sound emitted by a virtual sound source VS located at an arbitrary position to the sound output devices 3a and 3b built into the headphones 4, and generates sounds with different volumes and delays from the sound output devices 3a and 3b. The sound generated by sound output device 3a reaches the listener U's right ear, but the sound generated by sound output device 3b does not. Similarly, the sound generated by sound output device 3b reaches the listener U's left ear, while the sound generated by sound output device 3a The sound does not reach the destination. Therefore, in this embodiment, no crosstalk occurs between the sound generated by sound output device 3a and the sound generated by sound output device 3b, so the processing device 1 does not need to perform crosstalk cancellation processing.

[0148] Figure 24 shows an example of the configuration of the processing unit 1 of the fourth embodiment. As shown in Figure 24, the processing unit 1 of the fourth embodiment differs from the processing unit 1 of the third embodiment shown in Figure 20 in that the output sound data generation unit 40 does not include a crosstalk canceller 45. That is, in the fourth embodiment, the right sound data DOR generated by adding the first channel sound data DOFR output from the filter processing unit 43a and the third channel sound data DORR output from the filter processing unit 43b is input to the amplifier 60a. Similarly, the left sound data DOL generated by adding the second channel sound data DOFL output from the filter processing unit 43a and the fourth channel sound data DORL output from the filter processing unit 43b is input to the amplifier 60b.

[0149] The other configurations and functions of the processing apparatus 1 of the fourth embodiment shown in Figure 24 are the same as those of the processing apparatus 1 of the third embodiment shown in Figure 20, so their description will be omitted.

[0150] Figure 25 is a flowchart showing the procedure of the processing method of the fourth embodiment. The processing method of the fourth embodiment is performed by the processing device 1 of the fourth embodiment shown in Figure 24. As shown in Figure 25, the procedure of the processing method of the fourth embodiment differs from the procedure of the processing method of the third embodiment shown in Figure 22 only in that the output sound data generation step S2 does not include the crosstalk cancellation step S80, so its explanation is omitted.

[0151] According to the processing device 1 of the fourth embodiment described above, since the listener U wears headphones 4 with built-in sound output devices 3a and 3b, there is no need to consider crosstalk between the sound reaching the listener U's right ear and the sound reaching the left ear, thus eliminating the need for a crosstalk canceller. Furthermore, the processing device 1 of the fourth embodiment provides the same effects as the processing device 1 of the third embodiment.

[0152] 1-5. Fifth Embodiment Hereinafter, regarding the processing apparatus 1 of the fifth embodiment, the same reference numerals will be used for components similar to those in any of the first to fourth embodiments, descriptions similar to those in any of the first to fourth embodiments will be omitted or simplified, and the description will mainly focus on aspects that differ from any of the first to fourth embodiments.

[0153] Figure 26 shows an example of the configuration of the processing unit 1 according to the fifth embodiment. As shown in Figure 26, the processing unit 1 according to the fifth embodiment comprises a control unit 10, a sound source memory 20, four amplifiers 60a, 60b, 60c, 60d, a storage unit 50, and a processing unit 200, and is connected to four sound output devices 3a, 3b, 3c, 3d. The processing unit 1 may be a single-chip semiconductor integrated circuit device, or it may be composed of multiple-chip semiconductor integrated circuit devices, or at least a part of it may be composed of electronic components other than semiconductor integrated circuit devices. For example, the control unit 10, the storage unit 50, and the processing unit 200 may be realized as a single-chip semiconductor integrated circuit device, and the sound source memory 20 and amplifiers 60a, 60b, 60c, 60d may be provided outside of the semiconductor integrated circuit device. Note that the processing unit 1 may have some of the components of Figure 26 omitted or changed, or other components added. For example, the amplifiers 60a, 60b, 60c, 60d do not have to be components of the processing unit 1.

[0154] The processing unit 200 acquires the sound source data SDI, performs predetermined calculations, and outputs 4-channel sound data SDFR, SDFL, SDRR, and SDRL. Specifically, the processing unit 200 executes the processing program 301 stored in the information storage medium 300, and the sound source data The processing unit 200 performs various calculations on SDI. The processing unit 200 is implemented by, for example, a CPU or a DSP. CPU is an abbreviation for Central Processing Unit, and DSP is an abbreviation for Digital Signal Processor. The information storage medium 300 is implemented by, for example, a hard disk, flexible disk, MO, MT, various types of memory, CD-ROM, or DVD-ROM.

[0155] The processing unit 200, by executing the processing program 301, functions as the distance calculation unit 31, parameter calculation unit 32, and sound data generation units 33a, 33b, 33c, 33d included in the sound processing unit 30, as well as the crosstalk cancellers 41a, 41b included in the output sound data generation unit 40, and executes each step of the flowchart shown in Figure 10. In other words, the processing program 301 is a program that causes the processing unit 1, which is a computer, to execute each step of the flowchart shown in Figure 10. In this way, the processing unit 1 of the fifth embodiment achieves the same functions as the processing unit 1 of the first embodiment shown in Figure 2 by having the processing unit 200 execute the processing program 301.

[0156] Furthermore, the processing unit 200 may function as the distance calculation unit 31, parameter calculation unit 32, and sound data generation units 33a, 33b, 33c, 33d included in the sound processing unit 30, as well as the crosstalk cancellers 41a, 41b and correction processing unit 42 included in the output sound data generation unit 40, by executing the processing program 301, and execute each step of the flowchart shown in Figure 17. In other words, the processing program 301 may be a program that causes the processing unit 1, which is a computer, to execute each step of the flowchart shown in Figure 17. That is, the processing unit 1 of the fifth embodiment may achieve the same functions as the processing unit 1 of the second embodiment shown in Figure 15 by having the processing unit 200 execute the processing program 301.

[0157] Furthermore, the processing unit 1 is connected to two sound output devices 3a and 3b, and the processing unit 200, by executing the processing program 301, may function as the distance calculation unit 31, parameter calculation unit 32, and sound data generation units 33a, 33b, 33c, and 33d included in the sound processing unit 30, as well as the filter processing units 43a, 43b, adder units 44a, 44b, and crosstalk canceller 45 included in the output sound data generation unit 40, and execute each step of the flowchart shown in Figure 22. In other words, the processing program 301 may be a program that causes the processing unit 1, which is a computer, to execute each step of the flowchart shown in Figure 22. That is, the processing unit 1 of the fifth embodiment may achieve the same functions as the processing unit 1 of the third embodiment shown in Figure 20 by having the processing unit 200 execute the processing program 301.

[0158] Furthermore, the processing unit 1 is connected to two sound output devices 3a and 3b, and the processing unit 200, by executing the processing program 301, functions as the distance calculation unit 31, parameter calculation unit 32, and sound data generation units 33a, 33b, 33c, and 33d included in the sound processing unit 30, as well as the filter processing units 43a, 43b and adder units 44a, 44b included in the output sound data generation unit 40, and may execute each step of the flowchart shown in Figure 25. In other words, the processing program 301 may be a program that causes the processing unit 1, which is a computer, to execute each step of the flowchart shown in Figure 25. That is, the processing unit 1 of the fifth embodiment may achieve the same functions as the processing unit 1 of the fourth embodiment shown in Figure 24 by having the processing unit 200 execute the processing program 301.

[0159] According to the processing apparatus 1 of the fifth embodiment described above, the same effects as those of any of the first to fourth embodiments can be obtained.

[0160] 1-6. Variations In each of the embodiments described above, the sound processing unit 30 generates sound data SDFR, SDFL, SDRR, and SDRL using a head model HM that models the listener U's head as a circle. However, a head model HM that models the listener U's head as a sphere may also be used. In this case, there are infinitely many tangents to the head model HM that pass through the position of the virtual sound source VS, so the distance calculation unit 31 calculates four tangents TL FR TL FL TL RR TL RL You may calculate four predetermined tangent lines.

[0161] Furthermore, in each of the above embodiments, the processing unit 1 generates stereoscopic sound data to be output to four sound output devices 3a, 3b, 3c, 3d or four sound output devices 3a, 3b. However, it may also generate stereoscopic sound data to be output to three or five or more sound output devices. In other words, the processing unit 1 only needs to generate stereoscopic sound data to be output to multiple sound output devices, and the number of sound output devices is not limited.

[0162] Furthermore, in each of the above embodiments, the sound processing unit 30 outputs the sound data of the first or second path as the first channel sound data SDFR, the sound data of the third or fourth path as the second channel sound data SDFL, the sound data of the first or fifth path as the third channel sound data SDRR, and the sound data of the third or sixth path as the fourth channel sound data SDRL, depending on the position of the virtual sound source VS. However, the sound data of the first to sixth paths may be output as the first to sixth channel sound data, respectively, regardless of the position of the virtual sound source VS. In this case, the output sound data generation unit 40 may include a sound data selection unit that, depending on the position of the virtual sound source VS, selects the sound data from the first or second path output from the sound processing unit 30 as the first channel sound data SDFR, selects the sound data from the third or fourth path output from the sound processing unit 30 as the second channel sound data SDFL, selects the sound data from the first or fifth path output from the sound processing unit 30 as the third channel sound data SDRR, selects the sound data from the third or sixth path output from the sound processing unit 30 as the fourth channel sound data SDRL, and outputs the selected sound data SDFR, SDFL, SDRR, and SDRL to a subsequent stage.

[0163] 2.Electronic equipment Figure 27 is a functional block diagram showing an example of the configuration of an electronic device using the processing unit 1 of any of the embodiments described above. In Figure 27, the same components as in Figures 2, 15, 20, or 24 are denoted by the same reference numerals.

[0164] As shown in Figure 27, the electronic device 400 of this embodiment includes a processing unit 1, a microcontroller unit 2, four sound output devices 3a, 3b, 3c, and 3d, a sensor 410, an operation unit 420, a storage unit 430, and a display unit 440. Note that the electronic device 400 of this embodiment may have some of the components shown in Figure 27 omitted or modified, or other components added.

[0165] The MCU2 performs control processing and various data processing for each part of the electronic device 400. For example, the MCU2 sends various commands to the processing unit 1 to control the operation of the processing unit 1. The MCU2 also performs various processing in response to detection signals from the sensor 410, various processing in response to operation signals from the operation unit 420, and processing to send display signals to display various information to the display unit 440.

[0166] Sensor 410 is any sensor, such as an accelerometer, angular velocity sensor, speed sensor, pressure sensor, or temperature sensor, and outputs a detection signal to MCU2.

[0167] The control unit 420 is an input device consisting of operation keys, button switches, etc., and outputs operation signals to the MCU2 in response to user operations.

[0168] The memory unit 430 stores programs, data, and other information for the MCU2 to perform various calculation and control processes. The memory unit 430 can be implemented as, for example, a hard disk, flexible disk, MO, MT, various types of memory, CD-ROM, or DVD-ROM.

[0169] The display unit 440 is a display device composed of an LCD or the like, and displays various information based on the input display signal. LCD is an abbreviation for Liquid Crystal Display. The display unit 440 may also be provided with a touch panel that functions as an operation unit 420.

[0170] The processing unit 1 generates sound signals DOa, DOb, DOc, and DOd based on various commands transmitted from the MCU 2 and outputs them to sound output devices 3a, 3b, 3c, and 3d, respectively. The sound output devices 3a, 3b, 3c, and 3d each output sound corresponding to the sound signals DOa, DOb, DOc, and DOd.

[0171] For example, MCU2 may send a command to the processing unit 1 to play a warning sound based on a detection signal from sensor 410. Alternatively, MCU2 may send a command to the processing unit 1 to play a guidance voice based on an operation signal from operation unit 420. Alternatively, MCU3 may send a command to the processing unit 1 to play various sounds such as sound effects, voices, and melodies at a predetermined timing. The processing unit 1 reads the sound source data stored in sound source memory 20 to generate sound signals DOa, DOb, DOc, and DOd, and outputs them to sound output devices 3a, 3b, 3c, and 3d, respectively. As a result, the sounds output from sound output devices 3a, 3b, 3c, and 3d are heard at listening position P U By mixing these sounds together, various warning sounds, sound effects, voices, melodies, etc., with a strong sense of direction are reproduced.

[0172] Such electronic devices 400 can include a variety of electronic devices, such as warning devices, televisions, car navigation systems, electronic game devices, fish finders, various measuring instruments, instruments for vehicles, aircraft, ships, etc., flight simulators, head-mounted displays, and the like.

[0173] The present invention is not limited to this embodiment, and various modifications can be implemented within the scope of the gist of the present invention.

[0174] The embodiments and variations described above are examples only and are not limited thereto. For example, each embodiment and each variation can be combined as appropriate.

[0175] The present invention includes configurations substantially identical to those described in the embodiments, for example, configurations with the same function, method, and results, or configurations with the same purpose and effect. Furthermore, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as those described in the embodiments. Finally, the present invention includes configurations that add known technology to the configurations described in the embodiments.

[0176] The following can be derived from the embodiments and modifications described above.

[0177] One aspect of the processing apparatus is: A sound processing unit that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, Based on the first and second sound data, output is made to multiple sound output devices. It comprises an output sound data generation unit that generates body sound data, The sound processing unit is If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

[0178] In this processing unit, the sound processing unit generates sound data with volume and delay corresponding to the sound reaching the listener's right or left ear in a straight line, provided that the path of sound generated by the virtual sound source to the listener's right or left ear is not obstructed by the listener's head. Furthermore, if the path of sound generated by the virtual sound source to the listener's right or left ear is obstructed by the listener's head, the sound processing unit generates sound data with volume and delay corresponding to the sound reaching the right or left ear after diffracting through a portion of the listener's head. Therefore, this processing unit can generate sound data that creates a sense of direction by considering diffracted sound passing through a portion of the listener's head, without blocking the direct sound reaching the listener's ear in a straight line from the virtual sound source. Additionally, this processing unit calculates the changes in sound characteristics from the virtual sound source to the listener's ear, considering not only volume but also delay, allowing the listener to obtain a more accurate sense of sound direction.

[0179] In one embodiment of the processing apparatus, The sound processing unit is When the first line segment intersects the head model at two points, Based on the length of the first arc, the first cutoff frequency is calculated. The first sound data is generated by setting the second volume and the second delay amount on the sound source data and performing low-pass filtering with the first cutoff frequency, When the third line segment intersects the head model at two points, The second cutoff frequency is calculated based on the length of the second arc. The second sound data may be generated by setting the fourth volume and the fourth delay amount to the sound source data and performing low-pass filtering of the second cutoff frequency.

[0180] This processing device allows for the adjustment of the attenuation rate of high-frequency sounds that are less likely to diffract around the listener's head, according to the diffraction distance, thus enabling the listener to obtain a more accurate sense of sound direction.

[0181] In one embodiment of the processing apparatus, The output sound data generation unit is, The system may also include a crosstalk canceller that reduces crosstalk between the first sound data and the second sound data based on the arrangement information of the plurality of sound output devices.

[0182] This processing device reduces crosstalk between sounds reaching the listener's right ear and sounds reaching their left ear, allowing the listener to perceive sound direction more accurately. It also generates sound data corresponding to sounds originating at a greater distance from the listener than all other sound output devices.

[0183] In one embodiment of the processing apparatus, The output sound data generation unit is, The system may also include a correction processing unit that corrects the volume and delay amount of the first sound data and the second sound data based on the arrangement information of the plurality of sound output devices.

[0184] According to this processing device, by correcting the volume and delay of the first and second sound data, each of the multiple sound output devices can generate sound with appropriate volume and delay according to its position, so that the listener can obtain a more accurate sense of sound direction.

[0185] In one embodiment of the processing apparatus, The second path is the path through which the sound generated by the virtual sound source diffracts through the frontal lobe of the head model and reaches the right ear. The fourth path may be a path through which the sound generated by the virtual sound source diffracts through the frontal lobe and reaches the left ear.

[0186] In one embodiment of the processing apparatus, The sound processing unit is When the first line segment intersects the head model at two points, The third tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the fifth path through which the sound generated by the virtual sound source diffracts through the back of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the fifth line segment connecting the third tangent and the third point of contact between the head model, and the length of the third arc connecting the third point of contact and the position of the right ear. Based on the distance of the fifth path, the fifth volume of the sound reaching the right ear via the fifth path and Then calculate the fifth delay amount, The third sound data is generated by setting the fifth volume and the fifth delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The fourth tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the sixth path through which the sound generated by the virtual sound source diffracts through the back of the head and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the sixth line segment connecting the fourth tangent and the fourth point of contact between the head model, and the length of the fourth circular arc connecting the fourth point of contact and the position of the left ear. Based on the distance of the sixth path, the sixth volume and sixth delay amount of the sound reaching the left ear via the sixth path are calculated. The sixth volume and sixth delay amount are set to the aforementioned sound source data to generate the fourth sound data. The output sound data generation unit is, The stereoscopic sound data may be generated based on the first sound data, the second sound data, the third sound data, and the fourth sound data.

[0187] This processing device can generate sound data that takes into account both sounds that diffract through the listener's forehead and sounds that diffract through the back of the head, allowing the listener to gain a more accurate sense of sound direction.

[0188] In one embodiment of the processing apparatus, The sound processing unit is If the first line segment intersects the head model at only one point, Based on the position of the virtual sound source, the first sound data is output as either the sound data for the first channel or the sound data for the third channel, and silent data is output as the other of the sound data for the first channel or the sound data for the third channel. When the first line segment intersects the head model at two points, The first sound data is output as the sound data for the first channel, and the third sound data is output as the sound data for the third channel. If the third line segment intersects the head model at only one point, Based on the position of the virtual sound source, the second sound data is output as either the sound data for the second channel or the sound data for the fourth channel, and silent data is output as the other of the sound data for the second channel or the sound data for the fourth channel. When the third line segment intersects the head model at two points, The second sound data may be output as sound data for the second channel, and the fourth sound data may be output as sound data for the fourth channel.

[0189] This processing device allows for the generation of four sounds corresponding to the first, second, third, and fourth sound data from four sound output devices, enabling listeners to obtain a more accurate sense of sound direction.

[0190] In one embodiment of the processing apparatus, The output sound data generation unit is, A first crosstalk canceller that reduces crosstalk between the audio data of the first channel and the audio data of the second channel, The system may also include a second crosstalk canceller that reduces crosstalk between the audio data of the third channel and the audio data of the fourth channel.

[0191] According to this processing device, the cross-sound reaching the listener's right ear and the sound reaching the left ear are detected. Because noise reduction is achieved, listeners can obtain a more accurate sense of sound direction, and sound data can also be generated that corresponds to sounds occurring at a greater distance from the listener than all other sound output devices.

[0192] In one embodiment of the processing apparatus, The output sound data generation unit is, The system may also include a correction processing unit that corrects the volume and delay amount of the first sound data, second sound data, third sound data, and fourth sound data based on the arrangement information of the plurality of sound output devices.

[0193] According to this processing device, by correcting the volume and delay of the first, second, third, and fourth sound data, each of the four sound output devices can generate sound with appropriate volume and delay according to its position, allowing the listener to obtain a more accurate sense of sound direction.

[0194] In one embodiment of the processing apparatus, The output sound data generation unit is, A first filter processing unit performs a first filter processing on the sound data of the first channel and the sound data of the second channel to emphasize the sense of direction of sound, A second filter processing unit performs a second filter processing on the sound data of the third channel and the sound data of the fourth channel to emphasize the sense of direction of sound, A first adder adds the sound data of the first channel that has undergone the first filtering process and the sound data of the third channel that has undergone the second filtering process to output right sound data, The system may also include a second adder that adds the sound data of the second channel, which has undergone the first filtering process, to the sound data of the fourth channel, which has undergone the second filtering process, and outputs left-side sound data.

[0195] This processing device allows for the generation of right-sound data and left-sound data, each with an emphasized sense of sound direction, from two sound output devices. Therefore, even with only two sound output devices, listeners can obtain a more accurate sense of sound direction.

[0196] In one embodiment of the processing apparatus, The output sound data generation unit is, The system may also include a crosstalk canceller that reduces crosstalk between the right audio data and the left audio data.

[0197] This processing device reduces crosstalk between sounds reaching the listener's right ear and sounds reaching their left ear, allowing the listener to perceive sound direction more accurately. It also generates sound data corresponding to sounds originating at a greater distance from the listener than all other sound output devices.

[0198] One aspect of the processing method is: A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, The process includes generating output sound data based on the first sound data and the second sound data to generate stereoscopic sound data to be output to multiple sound output devices, In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

[0199] In this processing method, during the sound processing step, if the path of sound generated by a virtual sound source directly reaching the listener's right or left ear is not obstructed by the listener's head, sound data with volume and delay corresponding to the sound directly reaching the listener's right or left ear is generated. Furthermore, during the sound processing step, if the path of sound generated by a virtual sound source directly reaching the listener's right or left ear is obstructed by the listener's head, sound data with volume and delay corresponding to the sound that diffracts through a part of the listener's head and reaches the right or left ear is generated. Therefore, this processing method makes it possible to generate sound data that creates a sense of direction by considering diffracted sound that passes through a part of the listener's head, without blocking the direct sound that travels directly from the virtual sound source to the listener's ear. In addition, this processing method calculates the changes in sound characteristics from the virtual sound source to the listener's ear, taking into account not only volume but also delay, so the listener can obtain a more accurate sense of sound direction.

[0200] One aspect of the processing program is: A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, A computer is instructed to perform an output sound data generation step, which generates stereoscopic sound data to be output to multiple sound output devices based on the first sound data and the second sound data. In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the aforementioned sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. The second sound data is generated by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

[0201] In this processing program, during the sound processing step, the computer generates sound data with volume and delay corresponding to the sound that reaches the listener's right or left ear in a straight line, provided that the path of sound generated by a virtual sound source to the listener's right or left ear is not obstructed by the listener's head. Furthermore, during the sound processing step, the computer generates sound data with volume and delay corresponding to the sound that diffracts through a portion of the listener's head before reaching the right or left ear, provided that the path of sound generated by a virtual sound source to the listener's right or left ear is obstructed by the listener's head. Therefore, this processing program allows the computer to generate sound data that creates a sense of direction by considering diffracted sound passing through a portion of the listener's head, without blocking the direct sound that reaches the listener's ear in a straight line from the virtual sound source. By calculating the changes in sound characteristics up to the point of arrival, taking into account not only volume but also delay, listeners can obtain a more accurate sense of sound direction. [Explanation of Symbols]

[0202] 1…Processing unit, 2…Microcontrol unit, 3a,3b,3c,3d…Sound output device, 4…Headphones, 10…Control unit, 20…Sound source memory, 21-1~21-m…Sound source data, 30…Sound processing unit, 31…Distance calculation unit, 32…Parameter calculation unit, 33a,33b,33c,33d…Sound data generation unit, 40…Output sound data generation unit, 41a,41b…Crosstalk canceller, 42…Correction processing unit, 43a,43b…Filter processing unit, 44a,44b…Addition unit, 45…Crosstalk canceller, 50…Storage unit, 51…Placement information, 60a,60b,60c,60d…Amplifier, 200…Processing unit, 300…Information storage medium, 301…Processing program, 400…Electronic device, 410…Sensor, 420…Operation unit, 430…Storage unit, 440…Display unit

Claims

1. A sound processing unit that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, The system includes an output sound data generation unit that generates stereoscopic sound data to be output to multiple sound output devices based on the first sound data and the second sound data, The sound processing unit is If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. A processing device that generates second sound data by setting the fourth volume and fourth delay amount to the sound source data.

2. In claim 1, The sound processing unit is When the first line segment intersects the head model at two points, Based on the length of the first arc, the first cutoff frequency is calculated. The first sound data is generated by setting the second volume and the second delay amount to the sound source data and performing low-pass filtering of the first cutoff frequency. When the third line segment intersects the head model at two points, The second cutoff frequency is calculated based on the length of the second arc. A processing device that sets the fourth volume and the fourth delay amount for the sound source data and generates the second sound data by performing low-pass filtering of the second cutoff frequency.

3. In claim 1, The output sound data generation unit is, A processing device including a crosstalk canceller that reduces crosstalk between the first sound data and the second sound data based on the arrangement information of the plurality of sound output devices.

4. In claim 1, The output sound data generation unit is, A processing device including a correction processing unit that corrects the volume and delay amount of the first sound data and the second sound data, respectively, based on the arrangement information of the plurality of sound output devices.

5. In claim 1, The second path is the path through which the sound generated by the virtual sound source diffracts through the frontal lobe of the head model and reaches the right ear. The processing device wherein the fourth path is a path through which the sound generated by the virtual sound source diffracts through the forehead and reaches the left ear.

6. In claim 5, The sound processing unit is When the first line segment intersects the head model at two points, The third tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fifth path through which the sound generated by the virtual sound source diffracts through the back of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the fifth line segment connecting the third tangent and the third point of contact between the head model, and the length of the third arc connecting the third point of contact and the position of the right ear. Based on the distance of the fifth path, the fifth volume and fifth delay amount of the sound reaching the right ear via the fifth path are calculated. The third sound data is generated by setting the fifth volume and the fifth delay amount to the aforementioned sound source data. When the third line segment intersects the head model at two points, The fourth tangent line of the head model passing through the position of the virtual sound source is calculated, The distance of the sixth path through which the sound generated by the virtual sound source diffracts through the back of the head and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the sixth line segment connecting the fourth tangent and the fourth point of contact between the head model, and the length of the fourth circular arc connecting the fourth point of contact and the position of the left ear. Based on the distance of the sixth path, the sixth volume and sixth delay amount of the sound reaching the left ear via the sixth path are calculated. The sixth volume and sixth delay amount are set to the aforementioned sound source data to generate the fourth sound data. The output sound data generation unit is, A processing device that generates stereoscopic sound data based on the first sound data, the second sound data, the third sound data, and the fourth sound data.

7. In claim 6, The sound processing unit is When the first line segment intersects the head model at only one point, Based on the position of the virtual sound source, the first sound data is output as either the sound data for the first channel or the sound data for the third channel, and silent data is output as the other of the sound data for the first channel or the sound data for the third channel. When the first line segment intersects the head model at two points, The first sound data is output as the sound data for the first channel, and the third sound data is output as the sound data for the third channel. If the third line segment intersects the head model at only one point, Based on the position of the virtual sound source, the second sound data is output as either the sound data for the second channel or the sound data for the fourth channel, and silent data is output as the other of the sound data for the second channel or the sound data for the fourth channel. When the third line segment intersects the head model at two points, A processing device that outputs the second sound data as sound data for the second channel, and outputs the fourth sound data as sound data for the fourth channel.

8. In claim 7, The output sound data generation unit is, A first crosstalk canceller that reduces crosstalk between the audio data of the first channel and the audio data of the second channel, A processing device including a second crosstalk canceller that reduces crosstalk between the sound data of the third channel and the sound data of the fourth channel.

9. In claim 7, The output sound data generation unit is, A processing device including a correction processing unit that corrects the volume and delay amount of the first sound data, second sound data, third sound data, and fourth sound data based on the arrangement information of the plurality of sound output devices.

10. In claim 7, The output sound data generation unit is, A first filter processing unit performs a first filter processing on the sound data of the first channel and the sound data of the second channel to emphasize the sense of direction of sound, A second filter processing unit performs a second filter processing on the sound data of the third channel and the sound data of the fourth channel to emphasize the sense of direction of sound, A first adder adds the sound data of the first channel that has undergone the first filtering process and the sound data of the third channel that has undergone the second filtering process to output right sound data, A processing apparatus comprising: a second adder that adds the sound data of the second channel that has undergone the first filtering process and the sound data of the fourth channel that has undergone the second filtering process to output left sound data.

11. In claim 10, The output sound data generation unit is, A processing device including a crosstalk canceller that reduces crosstalk between the right sound data and the left sound data.

12. A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, The process includes generating output sound data based on the first sound data and the second sound data to generate stereoscopic sound data to be output to multiple sound output devices, In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first sound data is generated by setting the first volume and first delay amount to the sound source data. When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. A processing method for generating second sound data by setting the fourth volume and the fourth delay amount to the sound source data.

13. A sound processing step that generates first sound data and second sound data based on monaural sound source data and the position of a virtual sound source, A computer is instructed to perform an output sound data generation step, which generates stereoscopic sound data to be output to multiple sound output devices based on the first sound data and the second sound data. In the aforementioned sound processing step, If the first line segment connecting the position of the virtual sound source and the position of the right ear of a head model that represents the listener's head as a circle or sphere intersects the head model at only one point, The length of the first line segment is calculated as the distance of the first path through which the sound generated by the virtual sound source reaches the right ear in a straight line. Based on the distance of the first path, the first volume and first delay amount of the sound reaching the right ear via the first path are calculated. The first volume and first delay amount are set in the sound source data to generate the first sound data. accomplish, When the first line segment intersects the head model at two points, The first tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the second path through which the sound generated by the virtual sound source diffracts through a part of the head model and reaches the right ear is calculated as the sum of the position of the virtual sound source, the length of the second line segment connecting the first tangent and the first point of contact between the head model, and the length of the first arc connecting the first point of contact and the position of the right ear. Based on the distance of the second path, the second volume and second delay amount of the sound reaching the right ear via the second path are calculated. The first sound data is generated by setting the second volume and second delay amount to the sound source data. If the third line segment connecting the position of the virtual sound source and the position of the left ear of the head model intersects the head model at only one point, The length of the third line segment is calculated as the distance of the third path through which the sound generated by the virtual sound source reaches the left ear in a straight line. Based on the distance of the third path, the third volume and third delay amount of the sound reaching the left ear via the third path are calculated. The second sound data is generated by setting the third volume and third delay amount to the sound source data. When the third line segment intersects the head model at two points, The second tangent line of the head model passing through the position of the virtual sound source is calculated. The distance of the fourth path through which the sound generated by the virtual sound source diffracts a part of the head model and reaches the left ear is calculated as the sum of the position of the virtual sound source, the length of the fourth line segment connecting the second tangent line and the second point of contact between the head model, and the length of the second arc connecting the second point of contact and the position of the left ear. Based on the distance of the fourth path, the fourth volume and fourth delay amount of the sound reaching the left ear via the fourth path are calculated. A processing program that generates second sound data by setting the fourth volume and the fourth delay amount to the aforementioned sound source data.

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