Information processing method, program, and sound reproducing device

Abstract

This information processing method comprises: a first determination step for determining whether the type of a predetermined sound and the type of an external sound correspond with each other; a second determination step for comparing the incoming direction of the predetermined sound with the incoming direction of the external sound that has been analyzed to determine whether the incoming direction of the predetermined sound and the incoming direction of the external sound overlap with each other; and an adjusting step for performing, on the basis of the results of the first determination step and the second determination step, at least one of (a) adjustment of the sound pressure of at least one of the predetermined sound and the external sound, and (b) adjustment of the incoming direction of the predetermined sound.

Description

[Technical field]

[0001] The present disclosure relates to an audio reproduction device, and an information processing method and program related to the audio reproduction device. [Background technology]

[0002] Conventionally, there is known a technology relating to sound reproduction that allows a user to perceive three-dimensional sound by controlling the position of a sound image, which is a sensory sound source object, in a virtual three-dimensional space (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-18620 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, when a user is made to perceive a sound as a stereoscopic sound in a three-dimensional sound field, a sound that is difficult for the user to perceive may be generated. In the information processing method in the conventional sound reproducing device, etc., there are cases where appropriate processing is not performed for such a sound that is difficult to perceive.

[0005] In view of the above, an object of the present disclosure is to provide an information processing method and the like that allows a user to more appropriately perceive three-dimensional sound. [Means for solving the problem]

[0006] An information processing method according to one aspect of the present disclosure is an information processing method for generating an output sound signal from sound information including information about a predetermined sound and information about a predetermined direction, for allowing a user to perceive the predetermined sound as a sound arriving from an arrival direction in a three-dimensional sound field corresponding to the predetermined direction, the information processing method including a first analysis step of analyzing a type of the predetermined sound, a second analysis step of analyzing a type of an external sound heard by the user as a sound from outside, a third analysis step of analyzing the arrival direction of the external sound, and comparing the analyzed type of the predetermined sound with the analyzed type of the external sound. The method includes a first determination step of determining whether the type of the specified sound and the type of the external sound match by comparing the arrival direction of the specified sound with the analyzed arrival direction of the external sound, and a second determination step of determining whether the arrival direction of the specified sound and the arrival direction of the external sound overlap by comparing the arrival direction of the specified sound with the analyzed arrival direction of the external sound; and an adjustment step of performing at least one of (a) adjusting the sound pressure of at least one of the specified sound and the external sound, and (b) adjusting the arrival direction of the specified sound, based on the determination results of the first determination step and the second determination step.

[0007] Moreover, a sound reproducing device according to one aspect of the present disclosure is a sound reproducing device that generates an output sound signal from sound information including information about a predetermined sound and information about a predetermined direction, for allowing a user to perceive the predetermined sound as a sound arriving from an arrival direction in a three-dimensional sound field corresponding to the predetermined direction, and reproduces the output sound signal, the sound reproducing device including an acquisition unit that acquires the sound information, a first analysis unit that analyzes a type of the predetermined sound, a second analysis unit that analyzes a type of external sound heard by the user as a sound from outside, and a third analysis unit that analyzes the arrival direction of the external sound, and compares the analyzed type of the predetermined sound with the analyzed type of the external sound to obtain a previous sound. The device includes a first judgment unit that judges whether the type of the specified sound and the type of the external sound match, a second judgment unit that judges whether the direction of arrival of the specified sound and the direction of arrival of the external sound overlap by comparing the direction of arrival of the specified sound with the analyzed direction of arrival of the external sound, an adjustment unit that performs at least one of (a) adjusting the sound pressure of at least one of the specified sound and the external sound and (b) adjusting the direction of arrival of the specified sound based on the judgment results of the first judgment step and the second judgment step, and an output unit that outputs sound based on the output sound signal generated by the adjustment.

[0008] Furthermore, one aspect of the present disclosure can also be realized as a program for causing a computer to execute the above-described sound reproducing method.

[0009] In addition, these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0010] According to the present disclosure, it is possible to allow a user to perceive stereoscopic sound more appropriately. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a schematic diagram showing a use example of a sound reproducing device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing a functional configuration of the sound reproducing device according to the embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating a functional configuration of an acquisition unit according to the embodiment. [Figure 4] FIG. 4 is a block diagram illustrating a functional configuration of a filter selection unit according to the embodiment. [Diagram 5] FIG. 5 is a block diagram illustrating a functional configuration of an output sound generating unit according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing the operation of the sound reproducing device according to the embodiment. [Figure 7] FIG. 7 is a flowchart showing the operations of the first analysis unit and the second analysis unit according to the embodiment. [Figure 8] FIG. 8 is a first diagram illustrating the arrival direction of a predetermined sound by a selected stereophonic filter according to the embodiment. [Figure 9] FIG. 9 is a second diagram illustrating the arrival direction of a predetermined sound by a selected stereophonic filter according to the embodiment. [Figure 10] FIG. 10 is a third diagram illustrating the arrival direction of a predetermined sound by a selected stereophonic filter according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Knowledge on which the disclosure is based) Conventionally, there is known a technology related to sound reproduction for making a user perceive a three-dimensional sound by controlling the position of a sound image, which is a sound source object sensed by the user, in a virtual three-dimensional space (hereinafter, sometimes referred to as a three-dimensional sound field) (see, for example, Patent Document 1). By localizing a sound image at a predetermined position in the virtual three-dimensional space, the user can perceive the sound as if it were coming from a direction parallel to a line connecting the predetermined position and the user (i.e., a predetermined direction). In order to localize a sound image at a predetermined position in the virtual three-dimensional space in this way, for example, a calculation process is required to generate a time difference in arrival of the sound between both ears and a level difference (or sound pressure difference) between both ears that is perceived as a three-dimensional sound for the collected sound.

[0013] As an example of such a calculation process, a process of convolving a head-related transfer function for perceiving a sound as coming from a specific direction with a signal of a target sound is known. By carrying out the convolution process of this head-related transfer function with higher resolution, the sense of realism experienced by the user is improved. On the other hand, in such a sound listening environment, a phenomenon is known in which the sound becomes difficult to hear due to overlapping of external sounds that arrive from the outside and are heard by the user 99. In particular, in a situation in which the reproduced predetermined sound and an external sound of the same type and coming from the same direction exist, it may be difficult to distinguish between the predetermined sound and the external sound.

[0014] In recent years, there has been active development of technology related to virtual reality (VR). In virtual reality, the position of the virtual three-dimensional space does not follow the user's movement, and the main focus is on allowing the user to experience it as if he or she were moving in the virtual space. In particular, attempts have been made to enhance the sense of realism by incorporating auditory elements into visual elements in this virtual reality technology. For example, when a sound image is localized in front of a user, if the user turns to the right, the sound image moves to the left of the user, and if the user turns to the left, the sound image moves to the right of the user. In this way, it becomes necessary to move the localization position of the sound image in the virtual space in the opposite direction to the user's movement in response to the user's movement. Such processing is performed by applying a stereophonic filter to the original sound information.

[0015] In view of the above, the present disclosure implements more appropriate calculation processing to improve discrimination when a reproduced predetermined sound and an external sound arriving from the outside overlap, while utilizing a stereophonic filter that allows a user to perceive the sound as coming from a predetermined direction in a three-dimensional sound field. The present disclosure aims to provide an information processing method and the like that allows a user to perceive a stereophonic sound by this appropriate calculation processing.

[0016] More specifically, an information processing method according to one embodiment of the present disclosure is an information processing method for generating an output sound signal from sound information including information regarding a predetermined sound and information regarding a predetermined direction, for causing a user to perceive the predetermined sound as a sound arriving from an arrival direction in a three-dimensional sound field corresponding to a predetermined direction, and includes a first analysis step of analyzing the type of the predetermined sound, a second analysis step of analyzing the type of external sound heard by the user as a sound from outside, a third analysis step of analyzing the arrival direction of the external sound, a first judgment step of determining whether the type of the predetermined sound and the type of the external sound match by comparing the analyzed type of predetermined sound with the type of analyzed external sound, a second judgment step of determining whether the arrival direction of the predetermined sound and the arrival direction of the external sound overlap by comparing the arrival direction of the predetermined sound with the analyzed direction of arrival of the external sound, and an adjustment step of performing at least one of (a) adjusting the sound pressure of at least one of the predetermined sound and the external sound, and (b) adjusting the arrival direction of the predetermined sound based on the judgment results of the first judgment step and the second judgment step.

[0017] According to this information processing method, when the external sound and the specified sound influence each other due to at least one of the following reasons: the external sound and the specified sound overlap in arrival direction, and the external sound and the specified sound are the same in type, making it difficult for the user to hear either of them, by adjusting at least one of (a) and (b), it is possible to make it easier for the user to hear at least one of the external sound and the specified sound, and to allow the user to perceive a more appropriate three-dimensional sound.

[0018] Also, for example, in the adjustment step, if the first determination step determines that the type of the specified sound and the type of the external sound match, and the second determination step determines that the direction from which the specified sound comes and the direction from which the external sound comes overlap, then at least one of (a) and (b) may be performed.

[0019] According to this, when the directions from which the external sound and the specified sound come overlap and the types of the external sound and the specified sound match, causing the external sound and the specified sound to affect each other and making it difficult for the user to hear either of them, by adjusting at least one of (a) and (b), it is possible to make it easier to hear at least one of the external sound and the specified sound, and to allow the user to perceive a more appropriate three-dimensional sound.

[0020] Also, for example, in the adjustment step, as (a), a superimposed sound having an antiphase with the external sound may be generated and superimposed to attenuate the sound pressure of the external sound.

[0021] According to this, by having the user hear the superimposed sound superimposed on the external sound, the sound pressure of the external sound can be attenuated, allowing the user to perceive the specific sound more appropriately.

[0022] Also, for example, in the adjustment step, as (b), the arrival direction of the predetermined sound may be shifted by a preset angle in a direction away from the arrival direction of the external sound.

[0023] This makes it easier for the user to hear at least one of the external sound and the specified sound by preventing the direction from which the specified sound comes from from overlapping with the direction from which the external sound comes, thereby enabling the user to perceive three-dimensional sound more appropriately.

[0024] Also, for example, in the adjustment step, (b) information regarding the specified direction may be corrected so as to shift the direction from which the specified sound comes by a preset angle in a direction away from the direction from which the external sound comes.

[0025] According to this, the arrival direction of the predetermined sound and the arrival direction of the external sound are prevented from overlapping, making it easier to hear at least one of the external sound and the predetermined sound, and allowing the user to perceive a more appropriate three-dimensional sound. For this reason, by correcting the information on the predetermined direction contained in the sound information, the stereophonic filter selected thereafter can be a stereophonic filter that prevents the arrival direction of the predetermined sound and the arrival direction of the external sound from overlapping. As a result, it is easier to hear at least one of the external sound and the predetermined sound, and allowing the user to perceive a more appropriate three-dimensional sound.

[0026] Furthermore, for example, in the analysis of a specific sound type and the analysis of an external sound type, the sound to be analyzed may be divided into unit times in the time domain, and the divided sounds may be input into a machine learning model to calculate the likelihood for each of a number of pre-set types, and an analysis result may be output indicating that the input sound type corresponds to the type with the highest calculated likelihood.

[0027] According to this, using a machine learning model, it is possible to output as an analysis result that the sound to be analyzed corresponds to the type with the highest likelihood among multiple types set in advance.

[0028] Also, for example, the type of the predetermined sound and the type of the external sound may be two types: voice and non-voice.

[0029] With this, it is possible to determine whether the types of the external sound and the predetermined sound match, based on whether the types of the external sound and the predetermined sound are either voice or non-voice.

[0030] Also, for example, the determination of whether the direction of arrival of the specified sound and the direction of arrival of the external sound overlap is made based on whether the angular difference between the direction of arrival of the specified sound and the direction of arrival of the external sound is smaller than a threshold, and a first threshold which is the threshold when the direction of arrival of the specified sound and the direction of arrival of the external sound are on the rear side of a virtual boundary surface dividing the user's head into front and rear may be greater than a second threshold which is the threshold when the direction of arrival of the specified sound and the direction of arrival of the external sound are on the front side of the boundary surface.

[0031] According to this, it is possible to determine whether the directions of arrival of an external sound and a specified sound overlap on the rear side of the boundary surface, where the directions of arrival are more likely to be perceived as overlapping due to the large minimum discrimination angle of the directions of arrival, using a larger standard than on the front side of the boundary surface.

[0032] Moreover, a program according to one aspect of the present disclosure is a program for causing a computer to execute the information processing method described above.

[0033] According to this, it is possible to achieve the same effect as the above-described information processing method using a computer.

[0034] Moreover, a sound reproducing device according to one aspect of the present disclosure is a sound reproducing device that generates and reproduces an output sound signal from sound information including information about a predetermined sound and information about a predetermined direction, for allowing a user to perceive the predetermined sound as a sound arriving from an arrival direction in a three-dimensional sound field corresponding to the predetermined direction, and includes an acquisition unit that acquires sound information, a first analysis unit that analyzes a type of the predetermined sound, a second analysis unit that analyzes a type of external sound heard by the user as a sound from outside, a third analysis unit that analyzes the arrival direction of the external sound, and a comparison between the analyzed type of the predetermined sound and the analyzed type of the external sound. the first judgment unit that judges whether the type of the specified sound and the type of the external sound match; a second judgment unit that judges whether the direction of arrival of the specified sound and the direction of arrival of the external sound overlap by comparing the direction of arrival of the specified sound with the direction of arrival of the analyzed external sound; an adjustment unit that at least one of (a) adjusting the sound pressure of at least one of the specified sound and the external sound and (b) adjusting the direction of arrival of the specified sound based on the judgment results of the first judgment step and the second judgment step; and an output unit that outputs sound by an output sound signal generated by the adjustment.

[0035] According to this, it is possible to achieve the same effect as the information processing method described above.

[0036] Furthermore, these comprehensive or specific aspects may be realized in a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or may be realized in any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0037] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection forms of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, components that are not described in the independent claims are described as optional components. Note that each figure is a schematic diagram and is not necessarily illustrated strictly. In addition, in each figure, the same reference numerals are given to substantially the same configurations, and duplicated descriptions may be omitted or simplified.

[0038] In the following description, ordinal numbers such as first, second, and third may be attached to elements. These ordinal numbers are attached to elements in order to identify the elements and do not necessarily correspond to a meaningful order. These ordinal numbers may be rearranged, newly added, or removed as appropriate.

[0039] (Embodiment) [overview] First, an overview of the sound reproducing device according to the embodiment will be described. Fig. 1 is a schematic diagram showing a use example of the sound reproducing device according to the embodiment. Fig. 1 shows a user 99 using the sound reproducing device 100.

[0040] The sound reproducing device 100 shown in FIG. 1 is used simultaneously with the stereoscopic video reproducing device 200. By simultaneously viewing stereoscopic images and stereoscopic sounds, the images enhance the auditory realism and the sounds enhance the visual realism, respectively, allowing the user to experience the images and sounds as if they were at the scene where they were taken. For example, when an image (moving image) of people talking is displayed, it is known that even if the position of the sound image of the conversation sound is not aligned with the mouth of the person, the user 99 perceives the conversation sound as coming from the mouth of the person. In this way, the position of the sound image is corrected by visual information, and the sense of realism can be enhanced by combining the image and sound.

[0041] The three-dimensional video reproduction device 200 is an image display device worn on the head of the user 99. Therefore, the three-dimensional video reproduction device 200 moves integrally with the head of the user 99. For example, the three-dimensional video reproduction device 200 is a glasses-type device supported by the ears and nose of the user 99, as shown in the figure.

[0042] The stereoscopic video reproduction device 200 changes the image displayed in response to the movement of the user 99's head, thereby making the user 99 perceive the movement of his / her head in the three-dimensional image space. In other words, when an object in the three-dimensional image space is located in front of the user 99, when the user 99 turns to the right, the object moves to the left of the user 99, and when the user 99 turns to the left, the object moves to the right of the user. In this way, the stereoscopic video reproduction device 200 moves the three-dimensional image space in the opposite direction to the movement of the user 99 in response to the movement of the user 99.

[0043] The stereoscopic video reproduction device 200 displays two images with a parallax difference to each of the left and right eyes of the user 99. The user 99 can perceive the three-dimensional position of an object on the image based on the parallax difference between the displayed images. Note that when the user 99 uses the audio reproduction device 100 with his / her eyes closed, for example, when using the audio reproduction device 100 to reproduce healing sounds for sleep induction, the stereoscopic video reproduction device 200 does not need to be used at the same time. In other words, the stereoscopic video reproduction device 200 is not an essential component of the present disclosure.

[0044] The sound reproducing device 100 is a sound presentation device that is worn on the head of the user 99. Therefore, the sound reproducing device 100 moves integrally with the head of the user 99. For example, the sound reproducing device 100 in this embodiment is a so-called over-ear headphone type device. There is no particular limitation on the form of the sound reproducing device 100, and it may be, for example, two earplug-type devices that are independently worn on the left and right ears of the user 99. These two devices communicate with each other to present sounds for the right ear and the left ear in a synchronized manner.

[0045] The sound reproducing device 100 changes the sound presented in response to the movement of the head of the user 99, thereby making the user 99 perceive as if the user 99 is moving his / her head within the three-dimensional sound field. For this reason, as described above, the sound reproducing device 100 moves the three-dimensional sound field in the opposite direction to the movement of the user 99.

[0046] It is known that when a sound image presented to the user overlaps with an external sound that arrives from the outside and is heard by the user, it becomes difficult for the user 99 to distinguish between these sounds. The sound reproducing device 100 according to this embodiment corrects the sound presented by information processing so as to avoid this phenomenon, thereby making the user 99 perceive at least one of the sound image and the external sound. In other words, the sound reproducing device 100 detects the overlap between the sound image and the external sound and operates to eliminate this overlap, thereby making the user 99 perceive at least one of the sound image and the external sound.

[0047] [composition] Next, the configuration of the sound reproducing device 100 according to the present embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the functional configuration of the sound reproducing device according to the embodiment.

[0048] As shown in FIG. 2, the sound reproducing device 100 according to this embodiment includes a processing module 101, a communication module 102, a detector 103, and a driver 104.

[0049] The processing module 101 is an arithmetic device for performing various signal processing in the sound reproduction device 100. The processing module 101 is equipped with, for example, a processor and a memory, and performs various functions by the processor executing a program stored in the memory.

[0050] The processing module 101 includes an acquisition unit 111, a filter selection unit 121, an output sound generation unit 131, and a signal output unit 141. Details of each functional unit included in the processing module 101 will be described below together with details of the configuration other than the processing module 101.

[0051] The communication module 102 is an interface device for accepting input of sound information to the sound reproducing device 100. The communication module 102 includes, for example, an antenna and a signal converter, and receives sound information from an external device by wireless communication. More specifically, the communication module 102 receives a wireless signal indicating sound information converted into a format for wireless communication using the antenna, and reconverts the wireless signal into sound information using the signal converter. In this way, the sound reproducing device 100 acquires sound information from an external device by wireless communication. The sound information acquired by the communication module 102 is acquired by the acquisition unit 111. In this way, the sound information is input to the processing module 101. Note that the communication between the sound reproducing device 100 and the external device may be performed by wired communication.

[0052] The sound information acquired by the sound reproducing device 100 is encoded in a predetermined format such as MPEG-H 3D Audio (ISO / IEC 23008-3). As an example, the encoded sound information includes information about a predetermined sound reproduced by the sound reproducing device 100 and information about a localization position when the sound image of the sound is localized at a predetermined position in a three-dimensional sound field (i.e., the sound is perceived as coming from a predetermined direction), i.e., information about the predetermined direction. For example, the sound information includes information about a plurality of sounds including a first predetermined sound and a second predetermined sound, and the sound images are localized so that the sound images when the respective sounds are reproduced are perceived as coming from different directions in the three-dimensional sound field.

[0053] This stereoscopic sound can improve the sense of realism of the content being viewed, for example, together with the image viewed using the stereoscopic video reproducing device 200. The sound information may include only information about the predetermined sound. In this case, information about the predetermined direction may be acquired separately. As described above, the sound information includes the first sound information about the first predetermined sound and the second sound information about the second predetermined sound, but a plurality of pieces of sound information including these separately may be acquired and simultaneously reproduced to localize the sound image at different positions in the three-dimensional sound field. In this way, there is no particular limitation on the form of the input sound information, and it is sufficient that the sound reproducing device 100 is provided with an acquisition unit 111 that corresponds to various forms of sound information.

[0054] Here, an example of the acquisition unit 111 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing a functional configuration of the acquisition unit according to the embodiment. As shown in Fig. 3, the acquisition unit 111 in the present embodiment includes, for example, an encoded sound information input unit 112, a decode processing unit 113, and a sensing information input unit 114.

[0055] The encoded sound information input unit 112 is a processing unit to which the encoded (in other words, encoded) sound information acquired by the acquisition unit 111 is input. The encoded sound information input unit 112 outputs the input sound information to the decoding processing unit 113. The decoding processing unit 113 is a processing unit that decodes (in other words, decodes) the sound information output from the encoded sound information input unit 112 to generate information about a specific sound and information about a specific direction included in the sound information in a format used for subsequent processing. The sensing information input unit 114 will be described below together with the functions of the detector 103.

[0056] The detector 103 is a device for detecting the moving speed of the head of the user 99. The detector 103 is configured by combining various sensors used for detecting movement, such as a gyro sensor and an acceleration sensor. In this embodiment, the detector 103 is built in the sound reproducing device 100, but may be built in an external device, such as a stereoscopic image reproducing device 200 that operates in response to the movement of the head of the user 99 in the same manner as the sound reproducing device 100. In this case, the detector 103 does not need to be included in the sound reproducing device 100. In addition, the detector 103 may detect the movement of the user 99 by capturing an image of the head movement of the user 99 using an external imaging device or the like and processing the captured image.

[0057] The detector 103 is, for example, fixed integrally to the housing of the sound reproducing device 100 and detects the speed of movement of the housing. After the sound reproducing device 100 including the housing is worn by the user 99, it moves integrally with the head of the user 99, and as a result, the detector 103 can detect the speed of movement of the head of the user 99.

[0058] For example, the detector 103 may detect an amount of rotation about at least one of three mutually orthogonal axes in a three-dimensional space as a rotation axis, as the amount of movement of the head of the user 99, or may detect an amount of displacement about at least one of the above three axes as a displacement direction. Furthermore, the detector 103 may detect both the amount of rotation and the amount of displacement as the amount of movement of the head of the user 99.

[0059] The sensing information input unit 114 acquires the movement speed of the head of the user 99 from the detector 103. More specifically, the sensing information input unit 114 acquires the amount of head movement of the user 99 detected by the detector 103 per unit time as the movement speed. In this way, the sensing information input unit 114 acquires at least one of the rotation speed and the displacement speed from the detector 103. The amount of head movement of the user 99 acquired here is used to determine the coordinates and the orientation of the user 99 in the three-dimensional sound field. In the sound reproducing device 100, the relative position of the sound image is determined based on the determined coordinates and orientation of the user 99, and the sound is reproduced. Specifically, the above functions are realized by the filter selection unit 121 and the output sound generation unit 131.

[0060] The filter selection unit 121 is a processing unit that determines, based on the determined coordinates and orientation of the user 99, from which direction in the three-dimensional sound field the user 99 will perceive the predetermined sound as coming from, and selects a stereophonic filter to be applied to the predetermined sound. The stereophonic filter is a function filter that convolves a specific head-related transfer function with the input predetermined sound, thereby making the user 99 perceive the predetermined sound as coming from a specific direction based on the specific head-related transfer function. In other words, by inputting the predetermined sound (or information on the predetermined sound) to the stereophonic filter, a sound pressure difference, a time difference, a phase difference, and the like are generated between the left and right sound signals of the predetermined sound, and a sound signal that can reproduce the predetermined sound with a controlled arrival direction can be output.

[0061] A plurality of stereophonic filters to be candidates for selection are prepared in advance, for example, by adjusting for each user 99. The plurality of stereophonic filters are generated by calculation for each direction of arrival, and are stored in a storage device (not shown) for storing a plurality of stereophonic filters.

[0062] Here, an example of the filter selection unit 121 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing a functional configuration of the filter selection unit according to the embodiment. As shown in Fig. 4, the filter selection unit 121 in the present embodiment includes, for example, a first analysis unit 122, a second analysis unit 123, a third analysis unit 124, a first judgment unit 125, a second judgment unit 126, and an adjustment unit 127.

[0063] The first analysis unit 122 is a processing unit that analyzes the type of a predetermined sound included in the sound information. The first analysis unit 122 outputs, as an analysis result, information indicating which of a plurality of preset types the predetermined sound corresponds to.

[0064] The type of the predetermined sound may be, for example, a human voice or not, i.e., two types, voice and non-voice, or may be a type that does not require a specific object, such as a first type, a second type, etc., classified by frequency characteristics from the source of the sound. There is no particular limit to the number of types, and the number may be set according to the type of the predetermined sound included in the sound information and the type of external sound expected from the environment in which the sound reproducing device 100 is used. The description regarding the type of the predetermined sound also applies to the type of external sound.

[0065] The second analysis unit 123 is a processing unit that analyzes the type of an external sound that arrives from outside the sound reproducing device 100 and is heard by the user 99. The second analysis unit 123 obtains the following as a result of the analysis: External Sound The second analysis unit 123 outputs information on which of a plurality of preset types the external sound corresponds to. The analysis result of the type of external sound by the second analysis unit 123 is used for comparison with the type of the predetermined sound. Therefore, as the external sound, a sound that is expected to make it difficult to hear at least one of the predetermined sound and the external sound when it overlaps with the predetermined sound is used, and the others may be deleted. For example, the sound pressure of the predetermined sound is determined in advance by the sound information and the volume set by the user 99 in the sound reproduction device 100. Therefore, a threshold may be set for whether or not to use the predetermined sound as an external sound depending on whether it is within a sound pressure range that can sufficiently interfere with the reproduced predetermined sound.

[0066] The analysis of the type of the predetermined sound by the first analysis section 122 and the analysis of the type of the external sound by the second analysis section 123 will be described further below with reference to FIG.

[0067] The third analysis unit 124 is a processing unit that analyzes the arrival direction of the external sound. The third analysis unit 124 acquires the external sound picked up by each of the two or more sound collection devices as external sound information, and performs external sound analysis based on the external sound information between the two or more sound collection devices. but The same external sound is identified, and the arrival direction of the external sound is analyzed by calculation based on the arrival time difference, sound pressure difference, phase difference, etc. The third analysis unit 124 outputs information on the direction from which the external sound arrived with respect to the user 99 as the analysis result.

[0068] The first determination unit 125 is a processing unit that determines whether the type of the predetermined sound and the type of the external sound match. For this purpose, the first determination unit 125 acquires the analysis results of the first analysis unit 122 and the second analysis unit 123. Based on these analysis results, the first determination unit 125 determines whether the arrival directions of the predetermined sound and the external sound match. The first determination unit 125 outputs information indicating whether the type of the predetermined sound and the type of the external sound match as a determination result. Note that, when there are a plurality of predetermined sounds and a plurality of external sounds, the first determination unit 125 may perform a determination for all combinations of the predetermined sound and the external sound, or may perform a determination for all combinations of the predetermined sound and the external sound only within a predetermined range seen from the user 99.

[0069] The second determination unit 126 is a processing unit that determines whether the direction of arrival of the predetermined sound overlaps with the direction of arrival of the external sound based on the analysis result of the third analysis unit 124. The second determination unit 126 calculates the direction of arrival of the predetermined sound based on the predetermined direction included in the sound information and the coordinates and orientation of the user 99, and compares the calculated direction of arrival of the predetermined sound with the direction of arrival of the external sound to determine whether they overlap. In the determination of the second determination unit 126, the direction of arrival of the predetermined sound and the direction of arrival of the external sound do not need to completely match. For example, if it is known that the direction of arrival of the predetermined sound and the direction of arrival of the external sound interfere with each other and make it difficult for the user 99 to distinguish them if they are within a certain angle range, a threshold value for such an angle range may be set. This threshold value is influenced by the sound pressure of the specified sound, the sound pressure of external sounds, the minimum discrimination angle of the user 99, etc., so it may be set for each user 99, or it may be set as a fixed value such as 5 degrees, 10 degrees, 15 degrees, 20 degrees, etc. that is determined averagely for multiple users 99.

[0070] The adjustment unit 127 is a processing unit that performs adjustment to improve the discriminability of at least one of the predetermined sound and the external sound based on the judgment result of the first judgment unit 125 and the judgment result of the second judgment unit 126, and selects a stereophonic filter. The user 99 can set in advance which sound, the predetermined sound or the external sound, the discriminability of which the adjustment unit 127 will improve. The adjustment unit 127 reads this setting value, and performs adjustment to improve the discriminability of at least one of the predetermined sound and the external sound according to the setting value. The adjustment by the adjustment unit 127 will be described later together with the operation of the sound reproduction device 100.

[0071] The sound adjustment by the adjustment unit 127 is performed by changing the stereophonic filter from a stereophonic filter based on a predetermined direction in the original sound information to a stereophonic filter in the sound arrival direction for achieving the adjustment. In other words, the sound adjustment by the adjustment unit 127 can also be considered as determining the stereophonic filter after the change. As a result, the filter selection unit 121 selects and outputs the stereophonic filter after the change, which is the stereophonic filter as the initial value changed. The arrival direction of the sound in the output sound signal at this time is a direction different from the predetermined direction in the sound information.

[0072] Note that the stereophonic filter may be directly determined without setting the initial value of the stereophonic filter as described above. In other words, the change of the stereophonic filter is an expression used for convenience of explanation, and the present disclosure also includes directly selecting and outputting the stereophonic filter without using the initial value.

[0073] The output sound generation unit 131 is a processing unit that generates an output sound signal by using the stereophonic filter selected by the filter selection unit 121 and inputting information about a specific sound included in the sound information to the selected stereophonic filter.

[0074] Here, an example of the output sound generating unit 131 will be described with reference to FIG. 5. FIG. 5 is a block diagram showing a functional configuration of the output sound generating unit according to the embodiment. As shown in FIG. 5, the output sound generating unit 131 in the present embodiment includes, for example, a filter processing unit 132. The filter processing unit 132 sequentially reads in the filters continuously selected by the filter selection unit 121, and inputs information on the corresponding predetermined sound on the time axis, thereby continuously outputting a sound signal in which the arrival direction from which the predetermined sound arrives is controlled in the three-dimensional sound field. In this way, the sound information divided into processing unit times on the time axis is output as a continuous sound signal (output sound signal) on the time axis.

[0075] The signal output unit 141 is a functional unit that outputs the generated output sound signal to the driver 104. The signal output unit 141 generates a waveform signal by performing signal conversion from a digital signal to an analog signal based on the output sound signal, and generates sound waves in the driver 104 based on the waveform signal to present the sound to the user 99. The driver 104 has, for example, a diaphragm and a driving mechanism such as a magnet and a voice coil. The driver 104 operates the driving mechanism according to the waveform signal, and vibrates the diaphragm with the driving mechanism. In this way, the driver 104 generates sound waves by the vibration of the diaphragm according to the output sound signal, and the sound waves propagate through the air to the ears of the user 99, and the user 99 perceives the sound.

[0076] [Operation] Next, the operation of the above-described sound reproducing device 100 will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a flowchart showing the operation of the sound reproducing device according to the embodiment. Fig. 7 is a flowchart showing the operation of the first analysis unit and the second analysis unit according to the embodiment. First, when the operation of the sound reproducing device 100 is started, the acquisition unit 111 acquires sound information via the communication module 102. The sound information is decoded by the decoding processing unit 113 into information about a specific sound and information about a specific direction, and filter selection is started.

[0077] In the filter selection unit 121, a stereophonic filter that reproduces a predetermined sound so as to match the arrival direction set in advance in the content is read from a storage device or the like as an initial value.

[0078] The sound reproducing device 100 reproduces the sound by selecting and applying a stereophonic filter so that the predetermined sound arrives from the arrival direction. In parallel with the reproduction of the sound, the first analysis unit 122 analyzes the type of the reproduced predetermined sound (S101) and continuously outputs the analysis result. The analysis of the type of the predetermined sound by the first analysis unit 122 is performed as shown in FIG. 7. First, the first analysis unit 122 divides the predetermined sound into a predetermined processing unit time and generates divided data (S201). Next, the first analysis unit 122 inputs the divided data into a machine learning model such as a neural network constructed to cluster the divided data into classes associated with the types, and calculates the likelihood for each class (S202). As a result, the first analysis unit 122 determines that the input divided data is a type corresponding to the class with the highest likelihood, and outputs an analysis result indicating that the input divided data corresponds to the type with the highest likelihood (S203).

[0079] 6, the sound collection device for collecting external sound starts collecting external sound when the sound reproduction device 100 starts operating, and sequentially outputs external sound information to the second analysis unit 123. The second analysis unit 123, in the same manner as the first analysis unit 122, analyzes the type of external sound from the acquired external sound information (S102) and continuously outputs the analysis results.

[0080] Furthermore, the third analysis unit 124 analyzes the direction from which the external sound comes for the acquired external sound information and continuously outputs the analysis results. Since the analyses by the first analysis unit 122, the second analysis unit 123, and the third analysis unit 124 are performed in parallel, the order of steps S101 and S102 in the figure may be interchanged.

[0081] Next, the first determination unit 125 determines whether the type of the predetermined sound matches the type of the external sound (S103). If the type of the predetermined sound matches the type of the external sound (Yes in S103), the second determination unit 126 further determines whether the arrival direction of the predetermined sound overlaps with the arrival direction of the external sound (S104). If the arrival direction of the predetermined sound overlaps with the arrival direction of the external sound (Yes in S104), the adjustment unit 127 adjusts the stereophonic filter so as to improve the discriminability of the sound (S105). For example, the adjustment unit 127 determines a stereophonic filter to be changed to in order to change from an initial stereophonic filter whose arrival direction matches the predetermined direction to a stereophonic filter whose arrival direction differs from the predetermined direction. On the other hand, if the type of the specified sound does not match the type of the external sound (No in S103), and if the direction from which the specified sound comes does not overlap with the direction from which the external sound comes (No in S104), the filter selection unit 121 ends the processing and outputs the initial stereophonic filter as the selected stereophonic filter.

[0082] Hereinafter, the determination of the stereophonic filter by the adjustment unit 127 (in other words, changing the stereophonic filter) will be described with reference to Figs. 8 to 10. Fig. 8 is a first diagram for explaining the arrival direction of a predetermined sound by a selected stereophonic filter according to an embodiment. Fig. 9 is a second diagram for explaining the arrival direction of a predetermined sound by a selected stereophonic filter according to an embodiment. Fig. 10 is a third diagram for explaining the arrival direction of a predetermined sound by a selected stereophonic filter according to an embodiment. In Figs. 8 to 10, a user 99 in a posture with the upper direction of the paper facing forward is shown as a circle with a "U" added thereto, and the user 99 is in an upright posture perpendicular to the paper.

[0083] Furthermore, in Figs. 8 to 10, the positions where the predetermined sounds are localized are indicated by black circles, and icons of virtual sound sources according to the types of sounds are also shown.

[0084] Figure 8 As shown in FIG. 1, the position where the first predetermined sound is located at a certain time is the first position S1. At the same time, the first external sound arrives from the second position S2. The first predetermined sound and the first external sound are marked with the same speaker icon, and it can be seen that they are the same type. Therefore, the determination result by the first determination unit 125 indicates a match in type. The range marked with dot hatching in the figure (the front side in the figure) is a range that spreads from the arrival direction of the first predetermined sound and can be considered to be an arrival direction that overlaps with the first predetermined sound. Since the arrival direction of the first external sound is within this range, it can be seen that the first predetermined sound and the first external sound overlap.

[0085] Therefore, the determination result by the second determination unit 126 indicates an overlap of the arrival directions. As a result, in the example of FIG. 8, the stereophonic filter is changed so as to lower the sound pressure of the first external sound and improve the discriminability of the first predetermined sound. For this purpose, the adjustment unit 127 changes the stereophonic filter so as to generate a signal of the opposite phase of the first external sound from the external sound information of the first external sound and superimpose this signal. As a result, the output sound signal obtained by inputting information about the predetermined sound to the stereophonic filter is a signal to which a signal of the opposite phase of the first external sound is added, and the sound pressure of the first external sound is reduced by canceling out the arriving first external sound.

[0086] 8, the dashed line extending to the left and right of the user 99 indicates a virtual boundary surface dividing the user 99's head into the front and back. This boundary surface may be a surface along the ear canal of the user 99, a surface passing through the rearmost point of the user 99's auricle, or simply a surface passing through the center of gravity of the user 99's head. It is known that there is a difference in ease of hearing sounds before and after such a boundary surface, that is, in front and behind the user 99. Therefore, it is effective to make the characteristics of the stereophonic filter change different between the front side and the rear side of the boundary surface.

[0087] In FIG. 8, the position where the second predetermined sound is localized at the same time point as above is the third position S3. At the same time point, the second external sound arrives from the fourth position S4. The second predetermined sound and the second external sound are marked with the same speaker icon, and it can be seen that they are the same type. Therefore, the determination result by the first determination unit 125 indicates that the types match. In addition, the range marked with dot hatching in the figure (the rear side in the figure) is a range that spreads from the arrival direction of the second predetermined sound and can be considered to be an arrival direction that overlaps with the second predetermined sound. Since the arrival direction of the second external sound is within this range, it can be seen that the second predetermined sound and the second external sound overlap. Therefore, the determination result by the second determination unit 126 indicates that the arrival directions overlap. As a result, in the example of FIG. 8, the stereophonic filter is changed so as to lower the sound pressure of the second external sound and improve the discriminability of the second predetermined sound.

[0088] The first predetermined sound and the second predetermined sound are the same sound, but differ only in the direction of arrival, and the first external sound and the second external sound are the same sound, but differ only in the direction of arrival. However, the range in which the directions of arrival of the second predetermined sound and the second external sound on the rear side of the boundary surface can be considered to overlap is set to be larger than the range in which the directions of arrival of the first predetermined sound and the first external sound on the front side of the boundary surface can be considered to overlap. In this way, a configuration may be provided that corresponds to the width of the minimum discrimination angle for the direction of arrival of a sound arriving from the rear side (i.e., behind the user 99) compared to the front side.

[0089] As another example of adjustment by the adjustment unit 127, as shown in FIG. 9, a stereophonic filter that rotates the arrival direction may be changed so that the localization position of the first predetermined sound is set to the fifth position S1a. Here, the arrival direction of the first predetermined sound is rotated in a direction away from the arrival direction of the first external sound until the range with dot hatching does not overlap with the arrival direction of the external sound. In this example, the distinctiveness of both the first predetermined sound and the first external sound is improved, and the user 99 can hear them. The adjustment unit 127 can also simply reduce the sound pressure of the first predetermined sound to improve the distinctiveness of the first external sound and make it audible.

[0090] In addition, in the case shown in FIG. 10, the adjustment unit 127 may not change the stereophonic filter. As shown in FIG. 10, the third external sound arrives from the sixth position S5 and the fourth external sound arrives from the seventh position S6 with respect to the first predetermined sound. As shown in the figure, the first predetermined sound and the third external sound are different types of sounds with different icons attached, so they can be distinguished and heard even if their arrival directions overlap. In addition, the first predetermined sound and the fourth predetermined sound are the same type of sounds with the same speaker icon attached, but their arrival directions are sufficiently different, so they can be distinguished and heard. In this way, the identification unit 127 does not need to change the stereophonic filter when the determination result of the first determination unit 125 indicates that they are different types, and when the determination result of the second determination unit 126 indicates that the arrival directions do not overlap.

[0091] However, in cases where the sound types are different but the directions of arrival are completely the same, or where the sound pressures of the sound sources affect each other even if the directions of arrival do not overlap, the stereophonic filters may be changed.

[0092] In this manner, in the present embodiment, when it is difficult to distinguish between the specified sound and the external sound because the types of the specified sound and the external sound match and the directions from which the specified sound and the external sound come overlap, at least one of (a) adjusting the sound pressure of at least one of the specified sound and the external sound and (b) adjusting the direction from which the specified sound comes is performed. This improves the distinguishability of at least one of the specified sound and the external sound, making it easier to hear the one with improved distinguishability, thereby enabling the user 99 to perceive a more appropriate three-dimensional sound.

[0093] (Other embodiments) Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments.

[0094] For example, in the above embodiment, an example in which sound does not follow the movement of the user's head has been described, but the contents of the present disclosure are also effective in cases in which sound follows the movement of the user's head. In other words, in an operation in which the user perceives a predetermined sound as a sound arriving from a first position that moves relatively with the movement of the user's head, if the type of the predetermined sound and the external sound match and the arrival directions overlap, the stereophonic filter may be changed to improve the discriminability of at least one of them.

[0095] Also, for example, the sound reproducing device described in the above embodiment may be realized as a single device including all the components, or may be realized by allocating each function to a plurality of devices and coordinating the functions of the plurality of devices. In the latter case, an information processing device such as a smartphone, a tablet terminal, or a PC may be used as the device corresponding to the processing module.

[0096] As a configuration different from the above embodiment, for example, the decode processing unit can correct the original sound information to select a modified stereophonic filter. Specifically, the decode processing unit in this example is a processing unit that generates information about a specific direction included in the sound information and corrects the original sound information. The decode processing unit performs the same operations as the first analysis unit, the second analysis unit, the third analysis unit, the first judgment unit, and the second judgment unit, and then corrects the information about the specific direction so as to shift the arrival direction of the specific sound by a preset angle in a direction away from the arrival direction of the external sound as necessary. As a result, the modified stereophonic filter in the above embodiment is applied by simply selecting a stereophonic filter that specifies the arrival direction of the specific sound based on the corrected information about the specific direction output from the decode processing unit.

[0097] In this way, the information processing method and the like disclosed in the present application may be realized by correcting information about a specific direction in the original sound information. For example, by simply inserting the above-mentioned decoding processing unit in place of a processing unit that performs decoding processing in a conventional stereophonic sound reproducing device, it is possible to realize a sound reproducing device that can achieve the same effect as that disclosed in the present application.

[0098] The sound reproducing device of the present disclosure can also be realized as a sound processing device that is connected to a reproducing device having only a driver and outputs an output sound signal to the reproducing device using a stereophonic filter selected based on the acquired sound information. In this case, the sound processing device may be realized as hardware having a dedicated circuit, or as software for causing a general-purpose processor to execute a specific process.

[0099] In the above embodiment, the processes executed by a specific processing unit may be executed by another processing unit. The order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0100] In the above-described embodiment, each component may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

[0101] Furthermore, each component may be realized by hardware. For example, each component may be a circuit (or an integrated circuit). These circuits may form a single circuit as a whole, or each may be a separate circuit. Furthermore, each of these circuits may be a general-purpose circuit, or a dedicated circuit.

[0102] In addition, the general or specific aspects of the present disclosure may be realized in an apparatus, a device, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM. In addition, the general or specific aspects of the present disclosure may be realized in any combination of an apparatus, a device, a method, an integrated circuit, a computer program, and a recording medium.

[0103] For example, the present disclosure may be realized as an audio signal reproducing method executed by a computer, or as a program for causing a computer to execute the audio signal reproducing method. The present disclosure may be realized as a computer-readable non-transitory recording medium having such a program recorded thereon.

[0104] In addition, the present disclosure also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art may conceive, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present disclosure. [Industrial Applicability]

[0105] The present disclosure is useful in reproducing sound, for example, by allowing a user to perceive stereoscopic sound. [Explanation of symbols]

[0106] 99 users 100 Sound reproduction device 101 Processing Module 102 Communication module 103 Detector 104 Driver 111 Acquisition Department 112 Encoded audio information input section 113 Decoding processing section 114 Sensing information input section 121 Filter selection section 122 1st Analysis Department 123 Second Analysis Department 124 Third Analysis Department 125 1st Judgment Section 126 Second Judgment Section 127 Adjustment section 131 Output sound generation unit 132 Filter processing section 141 Signal output section 200 3D image playback device S1 1st position S1a 5th position S2 2nd position S3 3rd position S4 4th position S5 6th position S6 7th position

Claims

1. An information processing method for generating an output sound signal from sound information including information about a predetermined sound and information about a predetermined direction, for allowing a user to perceive the predetermined sound as a sound arriving from an arrival direction in a three-dimensional sound field corresponding to the predetermined direction, comprising: A first analysis step of analyzing the type of the predetermined sound; A second analysis step of analyzing a type of external sound heard by the user as a sound from the outside; A third analysis step of analyzing the direction from which the external sound comes; a first determination step of determining whether or not the type of the predetermined sound and the type of the external sound match by comparing the analyzed type of the predetermined sound with the analyzed type of the external sound; a second determination step of determining whether or not the arrival direction of the predetermined sound and the arrival direction of the external sound overlap by comparing the arrival direction of the predetermined sound with the analyzed arrival direction of the external sound; and (b) performing at least one of adjusting a sound pressure of at least one of the predetermined sound and the external sound and adjusting an arrival direction of the predetermined sound based on the determination results of the first determination step and the second determination step. Information processing methods.

2. In the adjustment step, when it is determined in the first determination step that the type of the predetermined sound and the type of the external sound match, and when it is determined in the second determination step that the arrival direction of the predetermined sound and the arrival direction of the external sound overlap, at least one of (a) and (b) is performed. The information processing method according to claim 1 .

3. In the adjusting step, as the step (a), a superimposed sound having an antiphase with the external sound is generated and superimposed to attenuate the sound pressure of the external sound.

3. The information processing method according to claim 1 or 2.

4. In the adjustment step, as the step (b), the arrival direction of the predetermined sound is shifted by a preset angle in a direction away from the arrival direction of the external sound. The information processing method according to any one of claims 1 to 3.

5. In the adjustment step, as the step (b), the information about the predetermined direction is corrected so that the arrival direction of the predetermined sound is shifted by a preset angle in a direction away from the arrival direction of the external sound. The information processing method according to claim 4.

6. In the analysis of the type of the predetermined sound and the analysis of the type of the external sound, The sound to be analyzed is divided into units of time in the time domain. By inputting the divided sounds into a machine learning model, the likelihood of each of multiple predefined types is calculated, Outputting an analysis result indicating that the type of the input sound corresponds to the type with the highest calculated likelihood. The information processing method according to any one of claims 1 to 5.

7. The predetermined sound type and the external sound type are two types: voice and non-voice. The information processing method according to any one of claims 1 to 6.

8. the determination of whether the arrival direction of the predetermined sound and the arrival direction of the external sound overlap is performed based on whether an angular difference between the arrival direction of the predetermined sound and the arrival direction of the external sound is smaller than a threshold value; A first threshold value, which is the threshold value when the arrival direction of the predetermined sound and the arrival direction of the external sound are on the rear side of a virtual boundary surface that divides the user's head into front and rear, is larger than a second threshold value, which is the threshold value when the arrival direction of the predetermined sound and the arrival direction of the external sound are on the front side of the boundary surface. The information processing method according to any one of claims 1 to 7.

9. A method for causing a computer to execute the information processing method according to any one of claims 1 to 8. program.

10. 1. A sound reproducing device that generates an output sound signal from sound information including information about a predetermined sound and information about a predetermined direction, for allowing a user to perceive the predetermined sound as a sound coming from an arrival direction in a three-dimensional sound field corresponding to the predetermined direction, and reproduces the output sound signal, An acquisition unit that acquires the sound information; A first analysis unit that analyzes the type of the predetermined sound; A second analysis unit that analyzes a type of an external sound heard by the user as a sound from the outside; A third analysis unit that analyzes the direction from which the external sound comes; a first determination unit that determines whether or not the type of the predetermined sound and the type of the external sound match by comparing the analyzed type of the predetermined sound with the analyzed type of the external sound; a second determination unit that determines whether or not the arrival direction of the predetermined sound and the arrival direction of the external sound overlap by comparing the arrival direction of the predetermined sound with the analyzed arrival direction of the external sound; an adjustment unit that performs at least one of (a) adjusting a sound pressure of at least one of the predetermined sound and the external sound, and (b) adjusting an arrival direction of the predetermined sound based on the determination results of the first determination unit and the second determination unit; an output unit that outputs a sound based on the output sound signal generated by the adjustment; Sound reproduction device.

Images