Sound control device, program and method

Abstract

The present invention provides an acoustic control device, program, and method that can improve the accuracy of sound image localization without using real-time control and by using only two speakers. [Solution] The sound control device includes a filter calculation unit that calculates a first filter coefficient and a second filter coefficient of a virtual sound image filter to be applied to a sound source signal based on head transfer characteristic data for each of a plurality of listening positions included in the listening area; a first filter processing unit that outputs a first sound source signal obtained by multiplying the sound source signal by the first filter coefficient to a first speaker; and a second filter processing unit that outputs a second sound source signal obtained by multiplying the sound source signal by the second filter coefficient to a second speaker. The head transfer characteristic data for each of the plurality of listening positions includes head transfer characteristic data measured for different head postures for each listening position.

Description

Technical Field

[0001] Embodiments of the present invention relate to an acoustic control device, a program, and a method.

Background Art

[0002] In the audio field, virtual sound image localization technology is known, which uses two or more speakers to localize a sound image at an arbitrary position different from the actual sound source. As a non-real-time control method among virtual sound image localization technologies, there is a method of adjusting the amplitude and phase of a sound source signal from each speaker by a virtual sound image filter created using a pre-measured head-related transfer function (HRTF). In recent years, there has been a demand for improving the sound image localization accuracy in non-real-time control methods.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments provide an acoustic control device, a program, and a method that can improve the sound image localization accuracy without using real-time control and by using only two speakers.

Means for Solving the Problems

[0005] One embodiment of the sound control device comprises a filter calculation unit, a first filter processing unit, and a second filter processing unit. The filter calculation unit calculates a first filter coefficient and a second filter coefficient of a virtual sound image filter to be applied to the sound source signal based on head transfer characteristic data for each of a plurality of listening positions included in the listening area. The first filter processing unit outputs a first sound source signal, obtained by multiplying the sound source signal by the first filter coefficient, to a first speaker. The second filter processing unit outputs a second sound source signal, obtained by multiplying the sound source signal by the second filter coefficient, to a second speaker. The head transfer characteristic data for each of the plurality of listening positions includes head transfer characteristic data measured for different head postures for each listening position. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows an example of the configuration of an acoustic control device according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the elements included in an acoustic control device. [Figure 3] Figure 3 shows the C-path and d-path at a single listening position. [Figure 4A] Figure 4A shows an example of head-borne characteristics measured in a single listening area. [Figure 4B] Figure 4B shows an example of head-borne characteristics measured in a single listening area. [Figure 5A] Figure 5A shows the characteristics of the direct transfer term (CLL) for the left ear when the head is in the listening position shown in Figure 3 and facing forward. [Figure 5B] Figure 5B shows the characteristics of the crosstalk transfer term CLR for the left ear when the head is in the listening position shown in Figure 3 and facing forward. [Figure 6] Figure 6 shows the C-path and d-path at one listening position when the head is not facing forward. [Figure 7A]Figure 7A shows the characteristics of the direct transfer term CLL for the left ear when the head is in the listening position shown in Figure 6 and is turned to the right. [Figure 7B] Figure 7B shows the characteristics of the crosstalk transfer term CLR for the left ear when the head is in the listening position shown in Figure 6 and is turned to the right. [Figure 8] Figure 8 shows the listening area in a modified example. [Figure 9] Figure 9 shows a modified example in which three listening areas are set. [Figure 10] Figure 10 shows an example of the hardware configuration of an acoustic control device. [Modes for carrying out the invention]

[0007] Embodiments will be described below with reference to the drawings. Figure 1 is a diagram showing an example of the configuration of an acoustic control device according to an embodiment. The acoustic control system 1 has an acoustic control device 10 and two speakers 20L and 20R.

[0008] The sound control device 10 filters the sound source signal for playback using a virtual sound image filter for virtual sound image localization, and outputs the filtered sound source signal to the two speakers 20L and 20R, respectively. The sound control device 10 will be described in more detail later.

[0009] Speakers 20L and 20R are sound sources that emit sound corresponding to the input sound source signal. Speaker 20L is positioned, for example, on the front left side as viewed from user U, who is located in the central listening area. Speaker 20R is positioned, for example, on the front right side as viewed from user U. Speakers 20L and 20R may be fixed-position speakers mounted on, for example, a television receiver. Here, Figure 1 shows a view of user U from above.

[0010] Next, the acoustic control device 10 will be described. Figure 2 is a block diagram showing the elements included in the acoustic control device 10. The acoustic control device 10 includes an acquisition unit 101, filter processing units 102L and 102R, and a filter storage unit 103. Furthermore, the acoustic control device 10 may also include a filter calculation unit 104 and a head-transfer characteristic data storage unit 105. The acoustic control device 10 may be mounted on a television receiver together with the speakers 20L and 20R. Of course, the acoustic control device 10 may be separate from the speakers 20L and 20R.

[0011] The acquisition unit 101 acquires the sound source signals to be reproduced by speakers 20L and 20R. The sound source signals may be those prepared in advance by the sound control device 10, or they may be input from outside the sound control device 10.

[0012] The filter processing unit 102L processes the sound source signal input from the acquisition unit 101 and the filter coefficients W, which are the first filter coefficients of the virtual sound image filter read from the filter storage unit 103. L The sound source signal is filtered by multiplying it by a factor. The filter processing unit 102L then outputs the L signal, which is the first sound source signal obtained by filtering, to the speaker 20L. The filter processing unit 102R also takes the sound source signal input from the acquisition unit 101 and the filter coefficient W, which is the second filter coefficient of the virtual sound image filter read from the filter storage unit 103. R The sound source signal is filtered by multiplying it by a factor. The filter processing unit 102R then outputs the R signal, which is the second sound source signal obtained by filtering, to the speaker 20R.

[0013] The filter memory unit 103 stores the filter coefficients W of the virtual sound image filter. L and W R I remember that.

[0014] The filter calculation unit 104 determines the filter coefficients W of the virtual sound image filter to be stored in the filter storage unit 103 based on the head-transfer characteristic data stored in the head-transfer characteristic data storage unit 105. L and W R The filter calculation unit 104 does not have to be located in the sound control device 10. In other words, the filter calculation unit 104 is located outside the sound control device 10, and the filter coefficients W of the virtual sound image filter are calculated by this external filter calculation unit 104. L and W R This may be stored in the filter storage unit 103.

[0015] The head-transfer characteristic data storage unit 105 stores head-transfer characteristic data. The head-transfer characteristic data includes head-transfer characteristic data for the C path, which is the sound propagation path from the speaker to the user U's ears, and head-transfer characteristic data for the d path, which is the sound propagation path from the virtual sound source to the user U's ears. As mentioned above, the head-transfer characteristic data storage unit 105 does not necessarily have to be provided in the sound control device 10.

[0016] FIG. 3 is a diagram showing each of the C path and the d path at one listening position. FIG. 3 shows the positional relationship as viewed from above the user U. In FIG. 3, the user U is facing directly the plane connecting the left speaker 20L and the right speaker 20R. The plane connecting the left speaker 20L and the right speaker 20R is, for example, a plane including the straight line connecting the left speaker 20L and the right speaker 20R, and is a plane perpendicular to the ground. That is, the plane connecting the left speaker 20L and the right speaker 20R is orthogonal to the plane connecting the user U, the left speaker 20L, and the right speaker 20R. And the listening position of the user U is a position from the left speaker 20L. In the direction from the left speaker 20L toward the right speaker 20R, at least one ear of the user U is located between the left speaker 20L and the right speaker 20R. Also, in FIG. 3, a virtual sound source S is set behind the listening position of the user U.

[0017] As shown in FIG. 3, the C path is the direct path C which is the sound propagation path from the speaker closer to the ear of the user U. LL And C RR is included. The direct path C LL is the propagation path from the speaker 20L to the left ear of the user U. The direct path C RR is the propagation path from the speaker 20R to the right ear of the user U. Further, the C path includes the crosstalk paths C RL and C LR which are the sound propagation paths from the speaker farther from the ear of the user U. The crosstalk path C RL is the propagation path from the speaker 20L to the right ear of the user U. The crosstalk path C LR is the propagation path from the speaker 20R to the left ear of the user U. That is, the head transfer characteristic data of the C path includes the head transfer characteristic data of the transfer terms corresponding to each of the propagation paths of C LL 、C RR 、C RL and C <00**********0>respectively.

[0018] <00**********3>On the other hand, as shown in Figure 3, the d-path is the sound propagation path d from a predetermined virtual sound source S to the user's ear. L and d R This includes the head transfer characteristics data of the d-path, L and d R This includes head-transfer characteristic data for each propagation path.

[0019] The C-pass head transfer characteristic data is obtained from the sound source signal measured by the dummy head when, for example, a dummy head is placed at the user U's position and sound is actually emitted from speakers 20L and 20R. The d-pass head transfer characteristic data is obtained from the sound source signal measured by the dummy head when, for example, a dummy head is placed at the user U's position and a speaker acting as a sound source is placed at the virtual sound source S's position and sound is emitted from the speaker. Here, the dummy head is a model of a human head configured to reproduce acoustic effects equivalent to those of a human head by incorporating microphones near the ears.

[0020] In this embodiment, head-transfer characteristic data is measured for a listening area that includes multiple listening positions for a single virtual sound source S. Furthermore, the head-transfer characteristic data for a single listening area in this embodiment includes head-transfer characteristic data for the frontal direction as well as head-transfer characteristic data for directions other than the frontal direction.

[0021] Figures 4A and 4B show an example of head-borne characteristics measured in a single listening area. In Figure 4A, one listening area includes five listening positions U1, U2, U3, U4, and U5. Figure 4A shows listening positions U1, U2, U3, U4, and U5 viewed from above. In other words, if user U is facing forward at a listening position, the top of user U's head will be visible. Figure 4B shows listening positions U1, U2, U3, U4, and U5 viewed from the speaker side. In other words, if user U is facing forward at a listening position, the user U's face directly in front will be visible. The spacing between listening positions is, for example, 5 cm. The spacing between listening positions can be determined according to the average human head size, etc.

[0022] In Figures 4A and 4B, at listening position U1, head transfer characteristic data is measured with the dummy head tilted to the left relative to the frontal view. In this embodiment, "head tilted" means that the face is perpendicular to the ground and at an angle to the normal n of the plane connecting the two speakers. In other words, tilting to the left relative to the frontal view means that the face is rotated to the left R1 with respect to the normal n, as shown in Figures 4A and 4B. The leftward direction R1 is the direction to the left with respect to the user U. At listening position U2, head transfer characteristic data is measured with the dummy head tilted to the left relative to the frontal view. In this embodiment, "head tilted" means that the side of the head is facing the ground. In other words, tilting to the left relative to the frontal view means that the face is rotated counterclockwise R2 with respect to the normal n, as shown in Figures 4A and 4B, and the left side of the head is facing the ground or downwards. Furthermore, at listening position U3, head transfer characteristic data is measured with the dummy head facing forward. In this embodiment, "facing forward" means that the face is facing the direction of the plane connecting the two speakers and is perpendicular to the normal n of the plane connecting the two speakers. At listening position U4, head transfer characteristic data is measured with the dummy head tilted to the right relative to the forward orientation. That is, tilting to the right relative to the forward orientation means that, as shown in Figures 4 and 4B, the face is rotated clockwise R4 relative to the normal n, and the right side of the head is facing the ground or downwards. At listening position U5, head transfer characteristic data is measured with the dummy head turned to the right relative to the forward orientation. That is, turning to the right relative to the forward orientation means that, as shown in Figures 4 and 4B, the face is rotated to the right R5 relative to the normal n. The rightward direction R5 is the direction to the right with respect to the user U.

[0023] Here, the number of listening positions included in one listening area is not limited to five. Furthermore, head transfer characteristic data for the same head orientation may be measured within a single listening area. Moreover, the head orientation is not limited to those shown in Figures 4A and 4B.

[0024] Next, the calculation of the virtual sound image filter by the filter calculation unit 104 will be described. In this embodiment, the filter calculation unit 104 calculates the virtual sound image filter based on the following equation (1).

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[0025] Equation (1) means that the filter coefficients of the virtual sound image filter are the average of the spatial path information for each listening position within the listening area. By radiating sound from speakers 20L and R using the virtual sound image filter shown in equation (1), the sense of rear localization is maintained even if the user U's head moves within the listening area. Furthermore, because the head transfer characteristic data averaged in equation (1) includes head transfer characteristic data for various postures, the sense of rear localization is maintained even if the user U's head posture changes within the listening area.

[0026] Here, it is more desirable that the head-to-head transfer characteristic data used in the calculation of equation (1) include head-to-head transfer characteristic data in which the amplitude of the crosstalk transfer term is equal to or greater than the amplitude of the direct transfer term.

[0027] Figure 5A shows the direct transmission term C for the left ear when the head is in the listening position shown in Figure 3 and facing forward. LL This figure shows the characteristics of [the system]. Figure 5B also shows the crosstalk transfer term C for the left ear when the head is in the listening position shown in Figure 3 and facing forward. LR This figure shows the characteristics of the sound source. The horizontal axis in Figures 5A and 5B is the reciprocal of the frequency fs of the sound source. The vertical axis in Figures 5A and 5B is the impulse response gain of the sound acquired by a dummy head placed at the listening position.

[0028] As is clear from the comparison of Figure 5A and Figure 5B, when the head is facing forward, the crosstalk transfer term C is usually LR The amplitude is the direct transfer term C LL The amplitude becomes smaller than that. This is because, when the head is facing forward, as shown in Figure 3, the sound transmitted through the direct path reaches user U's ear directly, while the sound transmitted through the crosstalk path passes through user U's head before reaching user U's ear. Due to attenuation when passing through user U's head, the crosstalk transmission term C LR The amplitude is the direct transfer term C LLThe amplitude becomes smaller than that of the direct transfer term. The fact that the amplitude of the crosstalk transfer term is smaller than that of the direct transfer term can be a factor in reducing the sense of localization of the sound image created by the virtual sound image filter.

[0029] In contrast, as shown in Figure 6, even if the listening position is the same as in Figure 3, if, for example, the head is turned to the right, the angle of incidence of the sound transmitting the crosstalk path to the head changes. This can shorten the distance the sound travels through the head. Figure 7A shows the direct transmission term C for the left ear when the head is in the listening position shown in Figure 6 and turned to the right. LL This figure shows the characteristics of [the system]. Figure 7B also shows the crosstalk transfer term C for the left ear when the head is in the listening position shown in Figure 6 and turned to the right. LR This is a diagram showing the characteristics.

[0030] As is clear from the comparison of Figure 7A and Figure 7B, when the head is not facing forward, the crosstalk transfer term C LR The amplitude is the direct transfer term C LL The amplitude can be equal to or greater than that of the direct transfer term. This is because, when the head is not facing forward, even if it is a crosstalk path, it can reach user U's ears directly without passing through user U's head. When the amplitude of the crosstalk transfer term becomes equal to or greater than the amplitude of the direct transfer term, the sense of sound localization by the created virtual sound image filter can be improved.

[0031] Here, a possible method for acquiring head-related transfer characteristic data such that the amplitude of the crosstalk transfer term is equal to or greater than the amplitude of the direct transfer term is to place a dummy head at the listening position, radiate sound from only one of speaker 20L and speaker 20R towards the dummy head, and then radiate sound from only the other of speaker 20L and speaker 20R. Based on the sound from speaker 20L collected by a microphone built into the left ear of the dummy head, the direct transfer term C for the left ear is calculated. LL A crosstalk transfer term C for the left ear can be generated based on the sound from speaker 20R collected by a microphone embedded in the left ear of the dummy head. LRA direct transfer term C for the right ear may be generated based on the sound from speaker 20R collected by a microphone built into the right ear of the dummy head. RR A crosstalk transfer term C for the right ear can be generated based on the sound from speaker 20L collected by a microphone embedded in the right ear of the dummy head. RL This can be generated. And the crosstalk transfer term C LR The amplitude and direct transfer term C LL The amplitude is compared with the crosstalk transfer term C. RL The amplitude and direct transfer term C RR The amplitude is compared with the crosstalk transfer term C. LR The amplitude of the direct transfer term C LL The amplitude is not equal to or greater than that of the crosstalk transfer term C. RL The amplitude is also the direct transfer term C RR If the amplitude is not equal to or greater than that of the dummy head, the same measurement is repeated after changing the head posture of the dummy head. Meanwhile, the crosstalk transfer term C LR The amplitude of the direct transfer term C LL The amplitude is equal to or greater than that of the crosstalk transfer term C. RL The amplitude of the direct transfer term C RR If the amplitude is equal to or greater than that, then C at that time LL , C RR , C RL and C LR This data is stored in the head-transfer characteristics data storage unit 105 as head-transfer characteristics data. Subsequently, the same measurement is performed after changing the listening position.

[0032] Furthermore, the sense of sound localization produced by the created virtual sound image filter can be evaluated by the sound pressure reproduction rate, which is the ratio of the sound pressure of the sound image to the target sound pressure. In the applicant's experiments, the posterior localization of a virtual sound image filter created using head transfer characteristic data simulating the user's posture was found to be improved compared to the posterior localization of a virtual sound image filter created using head transfer characteristic data only for the frontal orientation.

[0033] As described above, according to the embodiment, when creating a virtual sound image filter by averaging the head transfer characteristics of multiple listening positions within the listening area, by including head postures other than facing forward at the multiple listening positions, the sense of sound image localization can be maintained even if the user U's head posture changes within the listening area, without using a real-time control method and by using only two speakers.

[0034] Furthermore, according to the embodiment, a virtual sound image filter is created using head transfer characteristic data measured at a head posture in which the amplitude of the crosstalk transfer term is equal to or greater than the amplitude of the direct transfer term at each listening position. This is expected to further improve the sense of sound image localization.

[0035] (modified version) The following describes variations of the embodiment. In the embodiment, an example is shown in which there is one listening area. However, there may be two or more listening areas.

[0036] Figure 8 shows the listening area in the modified version. As shown in Figure 8, in the modified version, n listening areas i (i=1, 2, ..., n) are set parallel to the plane connecting the left speaker 20L and the right speaker 20R, including the front positions of the left speaker 20L and the right speaker 20R. In Figure 8, listening area 1 is the listening area including the front position of speaker 20L, and listening area n is the listening area including the front position of speaker 20R.

[0037] Each of the listening areas 1, 2, ..., n has Ni (i=1,2, ...,n) listening positions set. N1, N2, ..., Nn may or may not be equal. In other words, the number of listening positions included in each listening area may be determined as appropriate by the designer of the virtual sound image filter. For example, the number of listening positions may be set to be greatest in the central listening area, i.e., the listening area that includes speaker 20L and listening positions equidistant from 20L. Here, if the number of the listening position in each listening area is j (j=1,2, ...,Ni), then in the modified example, the filter calculation unit 104 creates a virtual sound image filter according to the following equation (2).

number

[0038] By radiating sound from speakers 20L and R using the virtual sound image filter shown in equation (2), the listening area can be expanded. Furthermore, by radiating sound from speakers 20L and R using the virtual sound image filter shown in equation (2), a stable sense of rearward localization can be obtained for each of the multiple users U who are simultaneously present in multiple listening areas.

[0039] In this modified example, the head transfer characteristic data for each listening area may include head transfer characteristic data for non-frontal orientations in addition to the frontal orientation data. Furthermore, each head transfer characteristic data may include data measured in a head orientation where the amplitude of the crosstalk transfer term is equal to or greater than the amplitude of the direct transfer term.

[0040] Furthermore, in Figure 8, listening areas 1, 2, ..., n are set to be adjacent to each other, but listening areas 1, 2, ..., n do not necessarily have to be adjacent. For example, the listening areas may consist only of listening area 1, which includes the front position of speaker 20L; listening area 2, which includes the intermediate position between speaker 20L and speaker 20R; and listening area 3, which includes the front position of speaker 20R, as shown in Figure 9. In the example shown in Figure 9, the filter calculation unit 104 can calculate a virtual sound image filter according to the following equation (3).

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[0041] Here, the listening area used for calculating the virtual sound image filter may be pre-set or selected by user U.

[0042] The modifications described above expand the listening position, which allows for the simultaneous localization of sound images for, for example, multiple people.

[0043] Next, an example of the hardware configuration of the sound control device 10 described in the above-mentioned embodiment and its modified examples will be explained using Figure 10. Figure 10 is a diagram showing an example of the hardware configuration of the sound control device 10.

[0044] As shown in Figure 10, the sound control device 10 includes a computer to which a processor 201, memory 202, storage 203, input interface 204, and communication device 205 are electrically connected.

[0045] The processor 201 is a processor that controls the overall operation of the sound control device 10. The processor 201 operates as the acquisition unit 101, the filter processing units 102L and 102R, and the filter calculation unit 104 by executing a sound control program stored, for example, in the storage 203. The processor 201 is, for example, a CPU. The processor 201 may also be an MPU, GPU, ASIC, FPGA, etc. The processor 201 may be a single CPU, etc., or multiple CPUs, etc. If the calculation of the virtual sound image filter is performed outside the sound control device 10, the processor 201 may be configured not to operate as the filter calculation unit 104.

[0046] Memory 202 includes ROM and RAM. ROM is non-volatile memory. ROM stores the startup program for the sound control device 10, etc. RAM is volatile memory. RAM is used, for example, as working memory during processing in the processor 201.

[0047] The storage 203 is, for example, a flash memory, a hard disk drive, or a solid-state drive. The storage 203 stores various programs executed by the processor 201, such as an acoustic control program. The storage 203 may also store filter coefficients as a filter storage unit 103, or store head-transfer characteristic data as a head-transfer characteristic data storage unit 105. Furthermore, the acoustic control device 10 may have a drive instead of or in addition to the storage 203. A drive is a device for reading data stored in another auxiliary storage device and recording medium, and includes, for example, a semiconductor memory drive (flash memory drive), a CD (compact disk) drive, a DVD (digital versatile disk) drive, etc. The type of drive may be appropriately selected according to the type of storage medium.

[0048] The input interface 204 is an input device such as a touch panel, keyboard, or mouse. When the input interface 204 is operated, a signal corresponding to the operation is input to the processor 201. The processor 201 performs various data processing in response to this signal. The input interface 204 can be used for user input by user U.

[0049] The communication device 205 is a communication device for the acoustic control device 10 to communicate with external equipment. The communication device 205 may be used, for example, to receive a virtual sound image filter calculated in the external equipment, or to receive head-transfer characteristic data stored in the external equipment. The communication device 205 may be a communication device for wired communication or a communication device for wireless communication.

[0050] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0051] 1 Acoustic control system, 10 Acoustic control device, 20L, 20R speakers, 101 Acquisition unit, 102L, 102R Filter processing unit, 103 Filter storage unit, 104 Filter calculation unit, 105 Head-to-Energy Transfer Characteristic data storage unit, 201 Processor, 202 Memory, 203 Storage, 204 Input interface, 205 Communication device.

Claims

1. A filter calculation unit calculates first and second filter coefficients of a virtual sound image filter applied to a sound source signal based on head transfer characteristic data for each of multiple listening positions included in the listening area. A first filter processing unit outputs a first sound source signal, obtained by multiplying the sound source signal by the first filter coefficient, to a first speaker. A second filter processing unit outputs a second sound source signal, obtained by multiplying the sound source signal by the second filter coefficient, to a second speaker. It is equipped with, The head transfer characteristic data for each of the multiple listening positions includes head transfer characteristic data measured for different head postures for each listening position. Acoustic control device.

2. The head transfer characteristic data for each of the multiple listening positions is data measured in a head posture where the amplitude of the first direct transfer term, which is the head transfer characteristic data for the sound propagation path from the first speaker to the user's left ear, is equal to the amplitude of the first crosstalk transfer term, which is the head transfer characteristic data for the sound propagation path from the second speaker to the user's left ear, or in a head posture where the amplitude of the second direct transfer term, which is the head transfer characteristic data for the sound propagation path from the second speaker to the user's right ear, is equal to the amplitude of the second crosstalk transfer term, which is the head transfer characteristic data for the sound propagation path from the first speaker to the user's right ear. The sound control device according to claim 1.

3. The head-transmission characteristic data is measured by a dummy head in a different position for each listening position, not directly facing the first speaker and the second speaker. The sound control device according to claim 1.

4. The listening areas are set up in multiple locations so as to face directly with respect to the plane connecting the first speaker and the second speaker, including the front of the first speaker and the front of the second speaker. The sound control device according to claim 1.

5. The filter calculation unit calculates the virtual sound image filter by weighting and averaging head transfer characteristic data for each listening area. The sound control device according to claim 1.

6. Based on head-transfer characteristic data for each of the multiple listening positions included in the listening area, the first and second filter coefficients of a virtual sound image filter applied to the sound source signal are calculated, The first sound source signal, obtained by multiplying the sound source signal by the first filter coefficient, is output to the first speaker. The second sound source signal, obtained by multiplying the aforementioned sound source signal by the second filter coefficient, is output to the second speaker. This is an audio control program for causing a computer to execute, The head transfer characteristic data for each of the multiple listening positions includes head transfer characteristic data measured for different head postures for each listening position. Sound control program.

7. Based on head-transfer characteristic data for each of the multiple listening positions included in the listening area, the first and second filter coefficients of a virtual sound image filter applied to the sound source signal are calculated, The first sound source signal, obtained by multiplying the sound source signal by the first filter coefficient, is output to the first speaker. The second sound source signal, obtained by multiplying the aforementioned sound source signal by the second filter coefficient, is output to the second speaker. It is equipped with, The head transfer characteristic data for each of the multiple listening positions includes head transfer characteristic data measured for different head postures for each listening position. Acoustic control method.

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