User device, common device, method thereby, and program

Abstract

According to the present invention, an individual acoustic signal specialized for a specific user, who is any one of a plurality of users, is presented to the specific user from an acoustic signal output device for the specific user at a timing synchronized with a common acoustic signal presented to the plurality of users from a common sound source.

Description

User device, common device, method using same, and program

[0001] The present invention relates to a technique for allowing multiple users to listen to an acoustic signal.

[0002] 2. Description of the Related Art There is known an acoustic signal output device that allows a user to listen to individual reproduced sounds while still being able to hear surrounding sounds (see, for example, Non-Patent Document 1).

[0003] “WHAT ARE OPEN-EAR HEADPHONES?”, [online], Bose Corporation, [Retrieved September 13, 2021], Internet <https: / / www.bose.com / en_us / better_with_bose / open-ear-headphones.html>

[0004] However, it cannot be said that the advantage of the audio signal output device, which allows individual reproduced sounds to be heard while still being able to hear surrounding sounds, is fully utilized.

[0005] In view of this, the present invention provides a diverse service that takes advantage of an audio signal output device that allows individual reproduced sounds to be heard while still being able to hear surrounding sounds.

[0006] At a timing synchronized with a common acoustic signal presented to a plurality of users from a common sound source, an individual acoustic signal specialized for a specific user, which is one of the plurality of users, is presented to the specific user from an acoustic signal output device for the specific user.

[0007] This makes it possible to provide a variety of services that take advantage of the audio signal output device, which allows individual reproduced sounds to be heard while still being able to hear surrounding sounds.

[0008] FIG. 1 is a diagram illustrating the configuration of a playback system according to an embodiment. FIG. 2 is a diagram illustrating the configurations of a user device and a common device according to an embodiment. FIG. 3 is a transparent perspective view illustrating the configuration of an acoustic signal output device that does not completely seal the ear canal. FIG. 4A is a transparent plan view illustrating the configuration of an acoustic signal output device that does not completely seal the ear canal. FIG. 4B is a transparent front view illustrating the configuration of an acoustic signal output device that does not completely seal the ear canal. FIG. 4C is a bottom view illustrating the configuration of an acoustic signal output device that does not completely seal the ear canal. FIG. 5A is a 4BA-4BA end view of FIG. 4B. FIG. 5B is a 4A-4A end view of FIG. 4A. FIG. 5C is a 4BC-4BC end view of FIG. 2B. FIG. 6 is a block diagram illustrating the hardware configuration of a user device and a common device according to an embodiment.

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] <Overall Configuration> As illustrated in FIG. 1, a playback system 1 of the first embodiment includes M user devices 11-1, ..., 11-M, M sets of acoustic signal output devices 10-1, ..., 10-M, N common devices 13-1, ..., 13-N, and N acoustic signal output devices 14-1, ..., 14-N. Here, M is an integer of 2 or greater, and m=1, ..., M. N is an integer of 1 or greater, and n=1, ..., N. M users 101-1, ..., 101-M use the playback system 1, and each user 101-m uses a user device 11-m and an acoustic signal output device 10-m. Note that the positions and orientations of the common devices 13-n and the acoustic signal output devices 14-n may be fixed or variable. The user 101-m wears the acoustic signal output device 10-m and can move together with the acoustic signal output device 10-m. The user device 11-m may be movable together with the user 101-m and the acoustic signal output device 10-m, or may be located at a location remote from the user 101-m and the acoustic signal output device 10-m. The user device 11-m is configured to be able to communicate with the acoustic signal output device 10-m and the acoustic signal output device 10-n via wired or wireless communication, and the acoustic signal output device 10-n is configured to be able to communicate with the acoustic signal output device 14-n via wired or wireless communication.

[0010] <Acoustic Signal Output Device 10-m> The acoustic signal output device 10-m is an acoustic signal output device for a user 101-m (an acoustic signal output device for a specific user). In this embodiment, an acoustic signal output device 10-m is illustrated as being worn by the user 101-m without completely sealing the ear canal, and emitting an acoustic signal (individual acoustic signal) specialized for each user 101-m (specific user) into the ear canal of the user 101-m. Examples of such acoustic signal output devices 10-m include open-ear earphones, headphones, audio sunglasses, head-mounted displays, neck speakers, bone conduction speakers, and other speakers. <User Device 11-m> As illustrated in FIG. 2, the user device 11-m of the first embodiment includes an individual information providing unit 111-m, a transmitting unit 112-m, a receiving unit 113-m, an input unit 114-m, and an individual playback unit 115-m.

[0011] <Common device 13-n> As illustrated in FIG. 2, the common device 13-n of the first embodiment has storage units 131-n, 133-n, a common playback unit 132-n, a receiving unit 134-n, an individual sound selection unit 135-n, and a transmitting unit 136-n (output unit).

[0012] <Acoustic signal output device 14-n> The acoustic signal output device 14-n (common sound source) is a device that allows multiple users (for example, M users 101-1, ..., 101-M) to hear a common acoustic signal (common acoustic signal). The acoustic signal output device 14-n may be any device that emits a common acoustic signal around the user 101-m. An example of the acoustic signal output device 14-n is a speaker.

[0013] <Pre-processing> As pre-processing, a common sound DB (database) representing a common (identical) sound signal (common sound signal) for multiple users (e.g., M users 101-1, ..., 101-M) is stored in the memory unit 131-n of the common device 13-n (FIG. 2). Examples of common sound signals include music, voice, sound effects, and environmental sounds. In addition, the memory unit 133-n stores an individual sound DB representing a sound signal (individual sound signal) specialized for each user 101-m (specific user). Examples of individual sound signals include music, voice, sound effects, and environmental sounds. The individual sound signal is a signal with content specialized for each user 101-m (specific user), and is, for example, a signal corresponding to at least one of the attributes, preferences, actions, posture, orientation, position, or situation of each user 101-m (specific user). The attributes of the user 101-m include, for example, age, gender, occupation, nationality, native language, learned language, learned language level, place of residence, family structure, income, educational background, work history, and perceptual / cognitive characteristics. The preferences of the user 101-m include, for example, music preference, vocal preference, content preference, tempo preference, voice preference, environmental sound preference, and environmental sound preference. The actions of the user 101-m include, for example, walking, running, turning, stopping, sitting, standing, speaking, and silence. The posture and orientation of the user 101-m include, for example, facing forward, facing backward, facing right, facing left, facing upward, facing downward, looking down, leaning back, a direction with an elevation / depression angle θ from a reference position, a direction with an azimuth angle σ from a reference position, and the like. The location of the user 101-m may be, for example, a location in a geographic coordinate system, a relative location to a reference location, or a relative location to another user device 11-m' (where m' ≠ m, m' ∈ {1, ..., M}). The reference location may be, for example, a fixed specific location, a moving specific location, the location of any of the common devices 13-n, or the location of any of the other user devices 11-m' (where m' ≠ m, m' ∈ {1, ..., M}). The status of the user 101-m may be, for example, participating, not participating, logged in, logged out, playing, not playing, studying, not studying, concentrated, distracted, fatigued, or awake. The individual acoustic signal is associated with registered individual information representing, for example, the corresponding user 101-m, their attributes, preferences, actions, posture, orientation, location, or status.The individual sound DB may be set only in a pre-processing, or may be updated in a subsequent update process.

[0014] <Processing> The common playback unit 132-n of the common device 13-n (FIG. 2) extracts a common acoustic signal from the common sound DB stored in the storage unit 131-n and outputs an output signal for presenting the common acoustic signal (information for presenting the common acoustic signal from a common sound source to multiple users) (step S132-n). This output signal is an electrical signal and is supplied to the acoustic signal output device 14-n via a wired or wireless connection. The acoustic signal output device 14-n (common sound source) presents (outputs) the common acoustic signal to multiple users in accordance with the supplied output signal. This common acoustic signal is emitted around the user device 11-m. The user 101-m can hear the common acoustic signal presented by the acoustic signal output device 14-n, but the volume and sound quality of the audible common acoustic signal may vary depending on the location and environment of the user 101-m. Depending on the location and environment of the user 101-m, the user 101-m may not be able to hear any of the common acoustic signals presented by any of the acoustic signal output devices 14-n, may be able to hear only the common acoustic signal presented by one of the acoustic signal output devices 14-n, or may be able to hear only the common acoustic signal presented by multiple acoustic signal output devices 14-n. １ , 14-n ２ (However, n １ ≠n ２ , n １ , n ２ ∈{1, ..., N}) can be heard (step S14-n).

[0015] The individual information providing unit 111-m of the user device 11-m (FIG. 2) obtains and outputs individual information specialized for the user 101-m. The individual information may be preset, input in real time, or acquired in real time. Examples of the individual information include at least one of the attributes, preferences, actions, posture, orientation, location, or situation of the user 101-m. Specific examples of the attributes, preferences, actions, posture, orientation, location, or situation are as described above. For example, the individual information providing unit 111-m can obtain the actions, posture, orientation, etc. of the user 101-m using an acceleration information sensor, camera, or microphone; obtain the position using a position sensor; detect the situation of the user 101-m using a computing device, biosignal sensor, camera, or the like; and detect the attributes, preferences, etc. of the user 101-m using a computing device in which personal information is stored (step S111-m). The individual information of the user 101-m output from the individual information providing unit 111-m is sent to the transmitting unit 112-m, and is then transmitted from the transmitting unit 112-m to the common device 13-n (step S112-m).

[0016] The receiving unit 134-n of the common device 13-n receives the individual information of the user 101-m transmitted from the user device 11-m and sends it to the individual sound selecting unit 135-n (step S134-n). The individual sound selecting unit 135-n uses the received individual information to search the individual sound DB in the storage unit 133-n and extracts the individual acoustic signal associated with the registered individual information corresponding to this individual information. The individual sound selecting unit 135-n cooperates with the common reproducing unit 132-n to generate individual playback control information for presenting the individual acoustic signal extracted from the individual sound DB from the acoustic signal output device 10-m at a timing synchronized with the aforementioned common acoustic signal. The individual sound selecting unit 135-n sends the individual playback control information to the transmitting unit 136-n (step S135-n).

[0017] The transmitting unit 136-n transmits the individual playback control information to the user device 11-m. That is, the transmitting unit 136-n (output unit) outputs information for presenting an individual audio signal specialized for a specific user, which is one of the multiple users, to the specific user from the audio signal output device for the specific user, at a timing synchronized with the common audio signal presented to the multiple users from the common audio source (step S136-n).

[0018] The individual playback control information is received by the receiving unit 113-m of the user device 11-m and sent to the individual playback unit 115-m (step S113-m). Based on the individual playback control information, the individual playback unit 115-m outputs an individual playback signal for presenting the individual audio signal extracted by the individual sound selection unit 135-n to the user 101-m via the audio signal output device 10-m, synchronized with the common audio signal output from the audio signal output device 14-n. In other words, the individual playback unit 115-m outputs an individual playback signal for presenting an individual audio signal specialized for a specific user, one of multiple users, to the specific user from the audio signal output device for the specific user, synchronized with the common audio signal presented to multiple users from a common audio source. Furthermore, the individual playback signal may be corrected or adjusted based on information input in advance or in real time via the input unit 114-m (step S115-m).

[0019] The individual reproduction signal is input to the acoustic signal output device 10-m. The acoustic signal output device 10-m outputs the individual acoustic signal extracted by the individual sound selection unit 135-n based on the individual reproduction signal, at a timing synchronized with the common acoustic signal output from the acoustic signal output device 14-n. As a result, the user 101-m hears the individual reproduction signal emitted from the acoustic signal output device 14-n, along with the common acoustic signal emitted from the acoustic signal output device 14-n, at a timing synchronized with the common acoustic signal. In particular, the acoustic signal output device 10-m of this embodiment is worn in the ear canal of the user 101-m without completely sealing it, and emits the individual acoustic signal into the ear canal of the user 101-m at a timing synchronized with the common acoustic signal. Therefore, even when wearing the acoustic signal output device 10-m, the user 101-m can hear the common acoustic signal emitted around them, and can hear the common acoustic signal and the individual acoustic signal in a synchronized state (step S10-m).

[0020] <Features of this embodiment> Each user 101-m can listen to a common audio signal presented to multiple users and an individual audio signal tailored to that user 101-m at synchronized timing. This makes it possible to provide diverse audio content or optimized audio content that reflects the attributes, preferences, actions, posture, orientation, location, or situation of each user 101-m.

[0021] [Variation 1 of the First Embodiment] In the first embodiment, the storage unit 133-n of the common device 13-n stores an individual sound DB representing individual sound signals specialized for each user 101-m. However, each user device 11-m may store an individual sound signal specialized for each user 101-m. In this case, the storage unit 133-n of the common device 13-n may be omitted. In this case, instead of step S135-n, the individual sound selection unit 135-n of the common device 13-n cooperates with the common playback unit 132-n to generate individual playback control information for presenting the individual sound signals stored in each user device 11-m from the sound signal output device 10-m at a timing synchronized with the common sound signal. This individual playback control information is sent to the transmission unit 136-n, and the transmission unit 136-n transmits the individual playback control information to the user device 11-m. The individual playback control information is received by the receiving unit 113-m of the user device 11-m and sent to the individual playback unit 115-m (step S113-m). Furthermore, the individual audio signal stored in the user device 11-m is also sent to the individual playback unit 115-m. Based on the individual playback control information and the individual audio signal, the individual playback unit 115-m outputs an individual playback signal for presenting this individual audio signal to the user 101-m via the audio signal output device 10-m, at a timing synchronized with the common audio signal output from the audio signal output device 14-n. The individual playback control information is sent to the individual playback unit 115-m. The subsequent steps are the same as steps S115-m and S10-m in the first embodiment.

[0022] [Variation 2 of the First Embodiment] Furthermore, if each user device 11-m stores an individual audio signal specific to each user 101-m, the user device 11-m may be provided with an individual audio selection unit. In this case, the individual audio selection unit of the user device 11-m selects an individual audio signal appropriate to the individual information (e.g., movement, posture, orientation, position, or situation) obtained by the individual information providing unit 111-m from the individual audio signals stored in the user device 11-m, and sends the selected individual audio signal to the individual playback unit 115-m. Based on the individual playback control information and the individual audio signal, the individual playback unit 115-m outputs an individual playback signal for presenting this individual audio signal to the user 101-m via the audio signal output device 10-m, synchronized with the common audio signal output from the audio signal output device 14-n. The rest of the process is the same as step S10-m of the first embodiment. In such a configuration, the individual audio selection unit 135-n may be omitted from the common device 13-n.

[0023] [Third Modification of the First Embodiment] Furthermore, ambient sounds of the user 101-m may be picked up by an acoustic signal sensor such as a microphone, and information about the ambient sounds may be input to the individual playback unit 115-m, which may then use the ambient sound information to optimize the playback timing of the individual acoustic signal.

[0024] [Second embodiment] In addition to a common acoustic signal presented to multiple users, an individual acoustic signal may be presented to each user 101-m at a timing specific to that user 101-m, or an individual acoustic signal that has undergone acoustic signal processing specific to that user 101-m may be presented to each user 101-m. The following description will focus on differences from the first embodiment, and the same reference numerals will be used to simplify the description of matters already described.

[0025] <Overall Configuration> As illustrated in FIG. 1, the playback system 2 of the second embodiment includes M user devices 21-1, ..., 21-M, M sets of acoustic signal output devices 10-1, ..., 10-M, N common devices 23-1, ..., 23-N, and N acoustic signal output devices 14-1, ..., 14-N. M users 101-1, ..., 101-M use the playback system 2, and each user 101-m uses a user device 21-m and an acoustic signal output device 10-m. The positions and orientations of the common device 23-n and the acoustic signal output device 14-n may be fixed or variable. The user 101-m wears the acoustic signal output device 10-m and is movable along with the acoustic signal output device 10-m. The user device 21-m may be movable together with the user 101-m and the acoustic signal output device 10-m, or may be located at a location remote from the user 101-m and the acoustic signal output device 10-m.

[0026] <User device 21-m> As illustrated in Figure 2, the user device 21-m of the second embodiment has an individual information providing unit 111-m, a transmitting unit 112-m, a receiving unit 213-m, an input unit 114-m, an individual playback unit 115-m, and an acoustic signal processing unit 216-m.

[0027] <Common device 23-n> As illustrated in FIG. 2, the common device 23-n of the second embodiment has storage units 131-n, 133-n, a common playback unit 132-n, a receiving unit 234-n, an individual sound selection unit 135-n, a transmitting unit 236-n (output unit), and an individual control determination unit 237-n.

[0028] <Pre-processing> The same as in the first embodiment.

[0029] <Processing> Instead of the common device 13-n, the common device 23-n executes the process of step S132-n, and the acoustic signal output device 14-n executes the process of step S14-n. Instead of the user device 11-m, the user device 21-m executes the processes of steps S111-m and S112-m.

[0030] The receiving unit 234-n of the common device 23-n receives the individual information of the user 101-m transmitted from the user device 21-m and sends it to the individual sound selecting unit 135-n and the individual control determining unit 237-n (step S134-n). The individual sound selecting unit 135-n uses the received individual information to search the individual sound DB in the storage unit 133-n and extracts the individual acoustic signal associated with the registered individual information corresponding to this individual information. The individual sound selecting unit 135-n cooperates with the common playback unit 132-n to generate individual playback control information for presenting the individual acoustic signal extracted from the individual sound DB from the acoustic signal output device 10-m at a timing synchronized with the aforementioned common acoustic signal. The individual sound selecting unit 135-n sends the individual playback control information to the transmitting unit 136-n (step S135-n).

[0031] Furthermore, the individual control determination unit 237-n uses the received individual information to obtain individual control information for controlling signal processing specialized for the user device 21-m (specific user). An example of signal processing specialized for the user device 21-m is processing for reproducing an individual audio signal in synchronization with a common audio signal at a timing specialized for the user device 21-m (specific user). For example, the optimal reproduction timing of the individual audio signal relative to the common audio signal may vary depending on the attributes of the user 101-m (e.g., age, nationality, native language, learned language, learned language level, perceptual / cognitive characteristics, etc.), preferences (e.g., musical preferences, tempo preferences, etc.), actions (e.g., walking, running, stopping, etc.), posture, orientation, position (e.g., relative position from the audio signal output device 14-n, etc.), and situation (e.g., concentration state, distraction state, fatigue state, wakefulness state, etc.). In such a case, the individual control determiner 237-n may determine the optimal playback timing of the individual audio signal relative to the common audio signal according to the received individual information, and obtain individual control information for playing the individual audio signal in synchronization with the common audio signal at a timing tailored to the user device 21-m (specific user). Another example of signal processing tailored to the user device 21-m is audio signal processing tailored to the user device 21-m (specific user). For example, the optimal audio signal processing for the individual audio signal may differ depending on the attributes of the user 101-m (e.g., age, nationality, native language, learned language, learned language level, perceptual / cognitive characteristics, etc.), preferences (e.g., musical preferences, tempo preferences, etc.), actions (e.g., walking, running, stopping, etc.), posture, orientation, position (e.g., relative position from the audio signal output device 14-n, etc.), and situation (e.g., concentration state, distraction state, fatigue state, wakefulness state, etc.). For example, when the acoustic signal processing is processing of convolving a head-related transfer function (HRTF) or a head-related impulse response (HRIR) with an individual acoustic signal, the head-related transfer function or head-related impulse response that reproduces an appropriate sense of presence, sense of distance, sense of direction, etc. may differ depending on the posture, orientation, or position of the user 101-m. Also, when the acoustic signal processing is panning or volume adjustment for the individual acoustic signal, the sound image localization and volume that can reproduce an appropriate sense of presence, sense of distance, sense of direction, etc. may differ depending on the posture, orientation, or position of the user 101-m.For example, if the acoustic signal processing involves applying a low-pass filter, a high-pass filter, a band-pass filter, or the like to the individual acoustic signal, the optimal passband and attenuation band may differ depending on the attributes of the user 101-m, such as their perceptual and cognitive characteristics, their preferences, such as musical tastes, and their states, such as their concentration, distraction, fatigue, and alertness. In such cases, the individual control determiner 237-n may obtain individual control information for performing acoustic signal processing specialized for a specific user, in accordance with the received individual information. The individual control determiner 237-n sends the above-mentioned individual control information to the transmitter 136-n (step S237-n).

[0032] The transmitting unit 236-n transmits the individual playback control information and the individual control information to the user device 21-m. That is, the transmitting unit 236-n (output unit) outputs information for presenting an individual audio signal specialized for a specific user, which is one of the multiple users, to the specific user from the audio signal output device for the specific user, at a timing synchronized with the common audio signal presented to the multiple users from the common audio source (step S236-n).

[0033] The individual playback control information and the individual control information are received by the receiving unit 213-m of the user device 21-m and sent to the audio signal processing unit 216-m (step S213-m).

[0034] The acoustic signal processing unit 216-m performs signal processing on the individual acoustic signal represented by the individual playback control information based on the individual control information, and generates and outputs new individual playback control information for presenting the processed individual acoustic signal from the acoustic signal output device 10-m at a timing synchronized with the common acoustic signal. For example, the acoustic signal processing unit 216-m may perform processing to reproduce the individual acoustic signal in synchronization with the common acoustic signal at a timing specialized for the user device 21-m, and then generate and output new individual playback control information for reproducing the resulting individual acoustic signal in synchronization with the common acoustic signal at a timing specialized for the user device 21-m. For example, the acoustic signal processing unit 216-m may perform acoustic signal processing specialized for the user device 21-m on the individual acoustic signal, and then generate and output new individual playback control information for presenting the resulting individual acoustic signal from the acoustic signal output device 10-m at a timing synchronized with the common acoustic signal. For example, the audio signal processing unit 216-m may perform audio signal processing specific to the user device 21-m on the individual audio signal, and then generate and output new individual playback control information for presentation from the audio signal output device 10-m at a timing specific to the user device 21-m and synchronized with the common audio signal. Furthermore, the new individual playback control information may be corrected or adjusted based on information input in advance or in real time from the input unit 114-m. The new individual playback control information is sent to the individual playback unit 115-m (step S216-m).

[0035] Based on the new individual playback control information, the individual playback unit 115-m outputs an individual playback signal for presenting the individual audio signal to the user 101-m via the audio signal output device 10-m at a timing synchronized with the common audio signal output from the audio signal output device 14-n. The individual playback signal is a signal with content specialized for a specific user based on the new individual playback control information. For example, the individual playback signal of this embodiment may include a signal that is played back in synchronization with the common audio signal at a timing specialized for the user device 21-m (specific user), or may include a signal that has undergone audio signal processing specialized for the user device 21-m (specific user). Furthermore, the individual playback signal may be corrected or adjusted based on information input in advance or information input in real time from the input unit 114-m (step S115-m).

[0036] The individual playback signal is input to the acoustic signal output device 10-m. Based on this individual playback signal, the acoustic signal output device 10-m presents the individual acoustic signal to the user 101-m at the acoustic signal output device 10-m at a timing synchronized with the common acoustic signal output from the acoustic signal output device 14-n. In this embodiment, for example, the individual acoustic signal is played back in synchronization with the common acoustic signal at a timing specialized for the user device 21-m, the individual acoustic signal that has undergone acoustic signal processing specialized for the user device 21-m is played back in synchronization with the common acoustic signal, or the individual acoustic signal that has undergone acoustic signal processing specialized for the user device 21-m is played back in synchronization with the common acoustic signal at a timing specialized for the user device 21-m (step S10-m).

[0037] <Features of this embodiment> Each user 101-m can listen to a common audio signal presented to multiple users and an individual audio signal tailored to each user 101-m at synchronized timing. This makes it possible to provide diverse audio content or optimized audio content that reflects the attributes, preferences, actions, posture, orientation, location, or situation of each user 101-m. Furthermore, this embodiment can perform timing and audio signal processing tailored to each user 101-m, making it possible to provide audio content that is further optimized for the sense of presence, distance, and direction for each user 101-m.

[0038] [Variation 1 of the Second Embodiment] In the second embodiment, the storage unit 133-n of the common device 23-n stores an individual sound DB representing individual sound signals specialized for each user 101-m. However, each user device 21-m may store an individual sound signal specialized for each user 101-m. In this case, the storage unit 133-n of the common device 23-n may be omitted. In this case, instead of step S135-n, the individual sound selection unit 135-n of the common device 23-n cooperates with the common playback unit 132-n to generate individual playback control information for presenting the individual sound signals stored in each user device 21-m from the sound signal output device 10-m at a timing synchronized with the common sound signal. This individual playback control information is sent to the transmission unit 136-n, and the transmission unit 136-n transmits the individual playback control information to the user device 21-m. The individual playback control information is received by the receiving unit 113-m of the user device 21-m and sent to the audio signal processing unit 216-m. Furthermore, the individual audio signal stored in the user device 21-m is also sent to the audio signal processing unit 216-m. The audio signal processing unit 216-m performs signal processing on this individual audio signal based on the individual control information, and generates and outputs new individual playback control information for presentation from the audio signal output device 10-m at a timing synchronized with the aforementioned common audio signal after signal processing. The new individual playback control information is sent to the individual playback unit 115-m. The subsequent steps are the same as steps S115-m and S10-m in the second embodiment.

[0039] [Variation 2 of the Second Embodiment] Furthermore, if each user device 21-m stores an individual audio signal specific to each user 101-m, the user device 21-m may be provided with an individual audio selection unit. In this case, the individual audio selection unit of the user device 21-m selects an individual audio signal appropriate to the individual information (e.g., movement, posture, orientation, position, or situation) obtained by the individual information providing unit 111-m from the individual audio signals stored in the user device 21-m, and sends the selected individual audio signal to the audio signal processing unit 216-m. The audio signal processing unit 216-m performs signal processing on the individual audio signal based on individual control information, and generates and outputs new individual playback control information for presentation from the audio signal output device 10-m of the processed individual audio signal at a timing synchronized with the aforementioned common audio signal. In such a configuration, the individual audio selection unit 135-n may be omitted from the common device 23-n.

[0040] [Variation 3 of the Second Embodiment] Furthermore, ambient sounds of the user 101-m may be picked up by an acoustic signal sensor such as a microphone, and information about the ambient sounds may be input to the acoustic signal processing unit 216-m, which may then use the ambient sound information to optimize the timing of playback of the individual acoustic signals.

[0041] [Variation 4 of Second Embodiment] In the second embodiment, the common device 23-n is provided with an individual control determination unit 237-n. However, the function of the individual control determination unit 237-n may be included in the audio signal processing unit 216-m of the user device 21-m. The audio signal processing unit 216-m performs signal processing on the individual audio signal based on the individual information (e.g., movement, posture, direction, position, or situation) obtained by the individual information providing unit 111-m, and generates and outputs new individual playback control information for presentation from the audio signal output device 10-m at a timing synchronized with the aforementioned common audio signal after signal processing. The rest is as described in the second embodiment.

[0042] [Fifth Modification of the Second Embodiment] In the second embodiment, the individual acoustic signal was a signal with content specialized for the user device 21-m (specific user). However, an individual acoustic signal common to all users 101-1, ..., 101-M may be played back in synchronization with the common acoustic signal at a timing specialized for each user device 21-m (specific user). Alternatively, an individual acoustic signal common to all users 101-1, ..., 101-M may be subjected to acoustic signal processing specialized for each user device 21-m (specific user), and the resulting new individual acoustic signal may be played back in synchronization with the common acoustic signal. Alternatively, an individual acoustic signal common to all users 101-1, ..., 101-M may be subjected to acoustic signal processing specialized for each user device 21-m (specific user), and the resulting new individual acoustic signal may be played back in synchronization with the common acoustic signal at a timing specialized for each user device 21-m (specific user). In such a case, instead of step S135-n in the second embodiment, the individual sound selection unit 135-n can generate individual playback control information to be presented from the audio signal output device 10-m at a timing synchronized with the common audio signal, which is an individual audio signal common to all users 101-1, ..., 101-M, and send it to the transmission unit 136-n.

[0043] [Example of the acoustic signal output device 10-m] An example of the acoustic signal output device 10-m of each of the above-mentioned embodiments is shown below. The acoustic signal output device 10-m in this example has a function to suppress sound leakage to the outside, and is particularly suitable for applications in which an acoustic signal specialized for each user device 21-m is played back only on the user device 21-m, as described in each embodiment and its modified examples.

[0044] An example of this acoustic signal output device 10-m is shown in Figures 3, 4A-4C, and 5A-5C. For simplicity's sake, the acoustic signal output devices 10-m will be referred to as the acoustic signal output device 10 without distinction. Similarly, the user 101-m, user device 11-m, and individual playback unit 115-m will be referred to as the user 101, user device 11, and individual playback unit 115.

[0045] As illustrated in Figures 3, 4A-4C, and 5A-5C, the acoustic signal output device 10 in this example has a driver unit 1011 that converts the individual playback signal output from the individual playback unit 115 of the user device 11 into an acoustic signal and outputs it, and a housing 1012 that houses the driver unit 1011 inside.

[0046] <Driver Unit 1011> The driver unit (speaker driver unit) 1011 is a device (device with speaker function) that emits (emits sound from) an acoustic signal AC1 (first acoustic signal) based on an input individual playback signal to one side (D1 direction), and emits an acoustic signal AC2 (second acoustic signal) that is an inverse phase signal (phase-inverted signal) of the acoustic signal AC1 or an approximate signal of the inverse phase signal to the other side (D2 direction). That is, the acoustic signal emitted from the driver unit 1011 to one side (D1 direction) will be referred to as the acoustic signal AC1 (first acoustic signal), and the acoustic signal emitted from the driver unit 1011 to the other side (D2 direction) will be referred to as the acoustic signal AC2 (second acoustic signal). For example, the driver unit 1011 includes a diaphragm 10113 that emits the acoustic signal AC1 in the D1 direction from one surface 10113a by vibration, and emits the acoustic signal AC2 in the D2 direction from the other surface 10113b by this vibration (FIG. 4B). In this example, the driver unit 1011 emits an acoustic signal AC1 from one surface 10111 in the direction D1, as the diaphragm 10113 vibrates based on the input individual playback signal, and emits an acoustic signal AC2, which is an inverse phase signal of the acoustic signal AC1 or a signal approximating the inverse phase signal, from the other surface 10112 in the direction D2. That is, the acoustic signal AC2 is emitted secondarily in conjunction with the emission of the acoustic signal AC1. Note that the D2 direction (the other side) is, for example, the opposite direction of the D1 direction (the one side), but the D2 direction does not need to be strictly the opposite direction of the D1 direction; it is sufficient that the D2 direction is different from the D1 direction. The relationship between the one side (D1 direction) and the other side (D2 direction) depends on the type and shape of the driver unit 1011. Furthermore, depending on the type and shape of the driver unit 1011, the acoustic signal AC2 may be strictly an inverse phase signal of the acoustic signal AC1, or the acoustic signal AC2 may be a signal approximating the inverse phase signal of the acoustic signal AC1. For example, the approximation signal of the opposite phase signal of acoustic signal AC1 may be (1) a signal obtained by shifting the phase of the opposite phase signal of acoustic signal AC1, (2) a signal obtained by changing (amplifying or attenuating) the amplitude of the opposite phase signal of acoustic signal AC1, or (3) a signal obtained by shifting the phase of the opposite phase signal of acoustic signal AC1 and then changing the amplitude.The phase difference between the opposite phase signal of the acoustic signal AC1 and its approximation signal is δ of one period of the opposite phase signal of the acoustic signal AC1. １ % or less. １ Examples of % are 1%, 3%, 5%, 10%, 20%, etc. Furthermore, it is desirable that the difference between the amplitude of the antiphase signal of acoustic signal AC1 and the amplitude of its approximation signal be δ2% or less of the amplitude of the antiphase signal of acoustic signal AC1. Examples of δ2% are 1%, 3%, 5%, 10%, 20%, etc. Note that examples of the type of driver unit 1011 include a dynamic type, a balanced armature type, a hybrid type of a dynamic type and a balanced armature type, and a capacitor type. Furthermore, there are no limitations on the shapes of the driver unit 1011 and the diaphragm 10113. In this example, for the sake of simplicity, an example is shown in which the outer shape of the driver unit 1011 is a substantially cylindrical shape with both end faces, and the diaphragm 10113 is a substantially disc-shaped, but this does not limit the present invention. For example, the outer shape of the driver unit 1011 may be a rectangular parallelepiped shape, or the diaphragm 10113 may be a dome-shaped shape.

[0047] <Housing 1012> Housing 1012 is a hollow member with an outer wall and houses driver unit 1011 inside. For example, driver unit 1011 is fixed to the end of housing 1012 on the D1 direction side. However, this does not limit the present invention. There are no limitations on the shape of housing 1012, but it is desirable that the shape of housing 1012 be rotationally symmetric (line symmetric) or approximately rotationally symmetric about axis A1 extending along the D1 direction. This makes it easy to provide sound hole 10123a (described in detail below) so as to reduce the variation in the energy of sound emitted from housing 1012 in each direction. As a result, it becomes easy to reduce sound leakage uniformly in each direction. For example, the housing 1012 has a first end face, which is a wall portion 10121, arranged on one side (the D1 direction side) of the driver unit 1011, a second end face, which is a wall portion 10122, arranged on the other side (the D2 direction side) of the driver unit 1011, and a side face, which is a wall portion 10123, which surrounds the space between the first end face and the second end face, centered on an axis A1 passing through the first end face and the second end face (FIGS. 4B and 5B). In this example, for simplicity of explanation, an example is shown in which the housing 1012 has a substantially cylindrical shape with both end faces. For example, the distance between the wall portion 10121 and the wall portion 10122 is 10 mm, and the wall portions 10121 and 10122 are circular with a radius of 10 mm. However, these are merely examples and do not limit the present invention. For example, the housing 1012 may have a substantially dome-shaped shape with walls at the ends, a hollow, substantially cubic shape, or any other three-dimensional shape. There is also no limitation on the material that constitutes the housing 1012. The housing 1012 may be made of a rigid body such as synthetic resin or metal, or may be made of an elastic body such as rubber.

[0048] <Sound holes 10121a, 10123a> The wall of housing 1012 is provided with sound hole 10121a (first sound hole) that guides acoustic signal AC1 (first acoustic signal) emitted from driver unit 1011 to the outside, and sound hole 10123a (second sound hole) that guides acoustic signal AC2 (second acoustic signal) emitted from driver unit 1011 to the outside. Sound hole 10121a and sound hole 10123a are, for example, through holes that penetrate the wall of housing 1012, but this does not limit the present invention. Sound hole 10121a and sound hole 10123a do not have to be through holes as long as they can guide acoustic signal AC1 and acoustic signal AC2 to the outside, respectively.

[0049] The acoustic signal AC1 emitted from the sound hole 10121a reaches the ear canal of the user 101 and is heard by the user 101. Meanwhile, an acoustic signal AC2, which is an inverse phase signal of the acoustic signal AC1 or an approximation of the inverse phase signal, is emitted from the sound hole 10123a. A portion of this acoustic signal AC2 cancels out a portion (sound leakage component) of the acoustic signal AC1 emitted from the sound hole 10121a. That is, the acoustic signal AC1 (first acoustic signal) is emitted from the sound hole 10121a (first sound hole) and the acoustic signal AC2 (second acoustic signal) is emitted from the sound hole 10123a (second sound hole), and thus the attenuation rate η of the acoustic signal AC1 (first acoustic signal) at position P2 (second position) relative to position P1 (first position) is １１ Set a predetermined value η ｔｈ or the attenuation amount η of the acoustic signal AC1 (first acoustic signal) at the position P2 (second position) relative to the position P1 (first position) １２ a predetermined value ω ｔｈ Here, position P1 (first point) is a predetermined point where the acoustic signal AC1 (first acoustic signal) emitted from the sound hole 10121a (first sound hole) arrives. On the other hand, position P2 (second point) is a predetermined point that is farther from the acoustic signal output device 10 than position P1 (first point). The predetermined value η ｔｈ is the attenuation rate η of an arbitrary or specific acoustic signal (sound) due to air propagation at a position P2 (second position) relative to a position P1 (first position). ２１ In addition, the predetermined value ωｔｈ is the attenuation η of an arbitrary or specific acoustic signal (sound) due to air propagation at a position P2 (second position) relative to a position P1 (first position). ２２ That is, the acoustic signal output device 10 of this example has an attenuation rate η １１ is the decay rate η ２１ A predetermined value η smaller than ｔｈ It is designed to be equal to or less than the attenuation η １２ is the attenuation η ２２ a predetermined value ω greater than ｔｈ The acoustic signal AC1 is propagated through the air from position P1 to position P2, and is attenuated due to this air propagation and the acoustic signal AC2. １１ is the magnitude AMP of the acoustic signal AC1 at the position P1 １ (AC1), the magnitude AMP of the acoustic signal AC1 at the position P2 attenuated due to air propagation and the acoustic signal AC2. ２ (AC1) ratio (AMP ２ (AC1) / AMP １ (AC1)). Also, the attenuation amount η １２ is the magnitude AMP １ (AC1) and size AMP ２ Difference from (AC1) (|AMP １ (AC1)-AMP ２ On the other hand, if the acoustic signal AC2 is not assumed, any or specific acoustic signal AC propagating through the air from the position P1 to the position P2 is ａｒ is attenuated due to air propagation, not due to the acoustic signal AC2. ２１ is the acoustic signal AC at position P1 ａｒ The magnitude of AMP １ (AC ａｒ ) at position P2, which is attenuated due to air propagation (attenuation without being attributable to acoustic signal AC2) ａｒ The magnitude of AMP ２ (AC ａｒ ) ratio (AMP ２ (AC ａｒ ) / AMP １ (AC ａｒ )) Also, the attenuation η２２ is the magnitude AMP １ (AC ａｒ ) and the magnitude AMP ２ (AC ａｒ ) and the difference (|AMP １ (AC ａｒ )-AMP ２ (AC ａｒ ) |). Examples of the magnitude of an acoustic signal include the sound pressure of the acoustic signal or the energy of the acoustic signal. Furthermore, the term "sound leakage component" refers to, for example, a component of the acoustic signal AC1 emitted from the sound hole 10121a that is likely to reach an area other than the user 101 wearing the acoustic signal output device 10 (e.g., a person other than the user 101 wearing the acoustic signal output device 10). For example, the term "sound leakage component" refers to a component of the acoustic signal AC1 that propagates in a direction other than direction D1. For example, the direct wave of the acoustic signal AC1 is mainly emitted from the sound hole 10121a, and the direct wave of the second acoustic signal is mainly emitted from the second sound hole. A portion of the direct wave of the acoustic signal AC1 emitted from the sound hole 10121a (the sound leakage component) is canceled out by interference with at least a portion of the direct wave of the acoustic signal AC2 emitted from the sound hole 10123a. However, this does not limit the present invention, and this cancellation can occur with waves other than direct waves. That is, the sound leakage component, which is at least one of the direct wave and the reflected wave of the acoustic signal AC1 emitted from the sound hole 10121a, may be canceled out by at least one of the direct wave and the reflected wave of the acoustic signal AC2 emitted from the sound hole 10123a, thereby suppressing sound leakage.

[0050] [Hardware Configuration of User Device and Common Device] The user devices 11-m, 21-m and the common devices 13-n, 23-n in each embodiment are devices configured by a general-purpose or dedicated computer having, for example, a processor (hardware processor) such as a CPU (central processing unit) and memories such as RAM (random-access memory) and ROM (read-only memory) executing a predetermined program. That is, the user devices 11-m, 21-m and the common devices 13-n, 23-n in each embodiment have, for example, processing circuitry configured to implement each of the components possessed by each device. This computer may have one processor and memory, or multiple processors and memories. This program may be installed on the computer or may be pre-recorded in a ROM or the like. Furthermore, some or all of the processing units may be configured using electronic circuits that independently realize processing functions, rather than electronic circuits that realize functional configurations by loading programs like a CPU. Furthermore, the electronic circuits constituting a single device may include multiple CPUs.

[0051] FIG. 6 is a block diagram illustrating the hardware configuration of the user devices 11-m, 21-m and the common devices 13-n, 23-n in each embodiment. As illustrated in FIG. 6, the user devices 11-m, 21-m and the common devices 13-n, 23-n in this example include a CPU (Central Processing Unit) 10a, an input unit 10b, an output unit 10c, a RAM (Random Access Memory) 10d, a ROM (Read Only Memory) 10e, an auxiliary storage device 10f, a communication unit 10h, and a bus 10g. The CPU 10a in this example includes a control unit 10aa, a calculation unit 10ab, and a register 10ac, and executes various calculation processes according to various programs loaded into the register 10ac. The input unit 10b is an input terminal, keyboard, mouse, touch panel, etc., through which data is input. The output unit 10c is an output terminal, display, etc., through which data is output. The communication unit 10h is a LAN card or the like controlled by the CPU 10a that has loaded a predetermined program. The RAM 10d is a static random access memory (SRAM) or dynamic random access memory (DRAM), and has a program area 10da where the predetermined program is stored and a data area 10db where various data is stored. The auxiliary storage device 10f is a hard disk, magneto-optical disk (MO), semiconductor memory, or the like, and has a program area 10fa where the predetermined program is stored and a data area 10fb where various data is stored. The bus 10g connects the CPU 10a, input unit 10b, output unit 10c, RAM 10d, ROM 10e, communication unit 10h, and auxiliary storage device 10f so that information can be exchanged. The CPU 10a writes the program stored in the program area 10fa of the auxiliary storage device 10f to the program area 10da of RAM 10d in accordance with the loaded OS (Operating System) program. Similarly, the CPU 10a writes various data stored in the data area 10fb of the auxiliary storage device 10f to the data area 10db of the RAM 10d.The addresses on RAM 10d where these programs and data are written are then stored in register 10ac of CPU 10a. Control unit 10aa of CPU 10a sequentially reads these addresses stored in register 10ac, reads the programs and data from the areas on RAM 10d indicated by the read addresses, causes calculation unit 10ab to sequentially execute the calculations indicated by the programs, and stores the calculation results in register 10ac. This configuration realizes the functional configuration of user devices 11-m, 21-m and common devices 13-n, 23-n.

[0052] The above-mentioned program can be recorded on a computer-readable recording medium. Examples of computer-readable recording media include non-transitory recording media. Examples of such recording media include magnetic recording devices, optical disks, magneto-optical recording media, and semiconductor memories.

[0053] This program may be distributed, for example, by selling, transferring, or lending a portable recording medium, such as a DVD or CD-ROM, on which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of a server computer and transferring the program from the server computer to other computers via a network. As described above, a computer that executes such a program may first temporarily store the program recorded on a portable recording medium or transferred from the server computer in its own storage device. Then, when executing a process, the computer reads the program stored in its own storage device and executes processing in accordance with the read program. Alternatively, the program may be executed by a computer that reads the program directly from a portable recording medium and executes processing in accordance with the program. Furthermore, the computer may execute processing in accordance with the received program each time a program is transferred from the server computer to the computer. Alternatively, the server computer may not transfer the program to the computer, but may instead execute the processing function simply by issuing an execution instruction and obtaining the results, thereby executing the processing described above through a so-called ASP (Application Service Provider) service. In this embodiment, the program includes information used for processing by an electronic computer that is equivalent to a program (such as data that is not a direct instruction to a computer but has properties that dictate computer processing).

[0054] In each embodiment, the device is configured by executing a predetermined program on a computer, but at least a part of the processing contents may be realized by hardware.

[0055] [Other Modifications] The present invention is not limited to the above-described embodiments. For example, in the above-described embodiments and modifications, an acoustic signal output device 10-m is exemplified, which is worn by a user 101-m without completely sealing the ear canal and emits an acoustic signal specialized for each user 101-m into the ear canal of that user 101-m. Such an acoustic signal output device 10-m that does not completely seal the ear canal is suitable for applications in which a common acoustic signal presented to multiple users and an individual acoustic signal specialized for each user 101-m are listened to at synchronized timing. However, instead of the acoustic signal output device 10-m that does not completely seal the ear canal, an acoustic signal output device that can capture a common acoustic signal emitted externally and present it to the user 101-m together with the individual acoustic signal may be used.

[0056] Furthermore, in the above-described embodiments and modifications, the common acoustic signal is reproduced from the acoustic signal output device 14-n. However, the common acoustic signal may be a peripheral sound such as an environmental sound, a natural sound, a live sound, or a speech sound. In such a case, the peripheral sound may be picked up by an acoustic signal sensor such as a microphone and sent to the common device 13-n, 23-n, and the individual sound selection unit 135-n of the common device 13-n, 23-n may generate individual reproduction control information for presenting the individual acoustic signal from the acoustic signal output device 10-m at a timing synchronized with the common acoustic signal, which is the peripheral sound.

[0057] Furthermore, the individual acoustic signal may be a signal corresponding to the relationship between the user 101-m (a specific user) and a user 101-m' (where m'∈{1, ..., M}, m'≠m) other than the user 101-m and included in the users 101-1, ..., 101-M (a plurality of users). For example, the individual acoustic signal presented to the user 101-m may differ depending on the distance between the user 101-m and the other users 101-m', or may differ depending on the number of other users 101-m' present in the unit area in which the user 101-m is present. Alternatively, when the user 101-m has a pre-registered relationship (e.g., they are acquaintances) with another user 101-m' present within a predetermined distance from the user 101-m, an individual acoustic signal different from that presented in other cases may be presented to the user 101-m. Such a relationship between user 101-m and other users 101-m' may be acquired in real time by individual information providing unit 111-m, may be set in advance in individual information providing unit 111-m, or may be input in real time to individual information providing unit 111-m.

[0058] Furthermore, the various processes described above may not only be executed in chronological order as described, but may also be executed in parallel or individually depending on the processing capacity of the device executing the processes or as necessary. Needless to say, other modifications are possible within the scope of the present invention.

[0059] The present invention can be used, for example, to provide audio commentary and play music for artworks in art museums, play audio and music in movies, video games, horror attractions at amusement parks, and virtual spaces, add sound to enhance the sense of realism at concerts and live performances, and play simultaneous interpretation audio for business, movies, tourism, and other occasions.

[0060] For example, in the case of use in an art museum or a movie theater, the original commentary audio or an explanation audio in the local language by a commentator is played as a common audio signal. In such a case, if a user does not master the language of the audio played in the common audio signal, they will be unable to understand the content. Here, dubbed audio tailored to the user's nationality, preferred language, and language level can be played individually for each user as an individual audio signal. For example, the following use scenarios are possible: At the venue: An English audio commentary is played as the common audio signal. Person A: Since Person A does not understand English at all, dubbed audio in Person A's native language is played as Person A's individual audio signal for all audio commentary. Person B: Since Person B can understand simple English, dubbed audio in Person A's native language is played as Person A's individual audio signal only for the parts that Person B finds difficult to understand. In such an example, attributes such as the user's native language, language of proficiency, and language level of proficiency are included in the individual information. Furthermore, the type and signal processing of the audio and sound effects that make up the individual audio signal may vary depending on the user's current location information. Furthermore, music tailored to the user's preferences may be played as an individual audio signal.

[0061] In the case of use in a concert or live performance, a live performance at a live venue may be heard by users as a common audio signal, and audio optimized for each user may be reproduced as an individual audio signal. In this example, all users hear the live performance at the venue. However, for example, the live performance does not include vocals. In this case, different vocal sounds may be reproduced as individual audio signals according to the user's pre-set preferences. Alternatively, the same vocal sound may be reproduced for all users as an individual audio signal, but by convolving a head-related transfer function or head-related impulse response according to each user's current position in the audio signal processing unit, all users may feel as if the vocal sound is coming from the direction of the live performance. Alternatively, the same vocal sound may be reproduced for all users as an individual audio signal, but the vocal sound may be reproduced only when each user is in a specific section. Such settings may be changeable in real time.

[0062] 1, 2 Reproduction system 10-m, 14-m Sound signal output device 11-m, 21-m User device 13-n, 23-n Common device 101-m User

Claims

1. an individual reproduction unit that outputs an individual reproduction signal for presenting an individual audio signal specialized for a specific user, which is any one of the multiple users, to the specific user from an audio signal output device for the specific user at a timing synchronized with a common audio signal presented to the multiple users from a common sound source; A user device having the

2. 2. The user device of claim 1, The common sound source emits the common acoustic signal around the specific user; The acoustic signal output device is a user device that is worn by the specific user without completely sealing the ear canal of the specific user and emits the individual acoustic signal into the ear canal of the specific user.

3. 2. The user device of claim 1, A user device, wherein the individual acoustic signal is a signal corresponding to at least one of the attributes, preferences, movements, postures, orientations, situations, or relationships between the specific user and users other than the specific user included in the plurality of users.

4. 2. The user device of claim 1, A user device, wherein the individual acoustic signal includes at least one of a signal having content specialized for the specific user, a signal that is played in synchronization with the common acoustic signal at a timing specialized for the specific user, or a signal that has been subjected to acoustic signal processing specialized for the specific user.

5. a common reproduction unit that outputs information for presenting a common acoustic signal to a plurality of users from a common sound source; an output unit that outputs information for presenting an individual audio signal specialized for a specific user, which is any one of the plurality of users, to the specific user from an audio signal output device for the specific user at a timing synchronized with the common audio signal; A common device having:

6. 1. A method by a user device, comprising: an individual reproduction step of outputting an individual audio signal specialized for a specific user, which is any one of the multiple users, from an audio signal output device for the specific user as an individual reproduction signal for presenting the specific user to the specific user at a timing synchronized with a common audio signal presented to the multiple users from a common sound source; The method according to claim 1,

7. A common device method comprising: a common reproduction step of outputting information for presenting a common acoustic signal to a plurality of users from a common sound source; an output step of outputting, at a timing synchronized with the common audio signal, an individual audio signal specialized for a specific user, which is any one of the plurality of users, from an audio signal output device for the specific user, information for presenting the specific user to the specific user; The method according to claim 1,

8. A program for causing a computer to function as the user device of claim 1 or the common device of claim 5.