Modulation method, modulation system, and program

Abstract

Provided is a modulation method in which, even when an acoustic apparatus is worn, changes in sound and spatial impression in the real world are less than those when the acoustic apparatus is not worn. This modulation method is executed by a modulation system. A first acoustic signal, which is derived from an acoustic signal emitted from a sound emission device disposed at a prescribed position and can arrive near an ear of a person or dummy head wearing an acoustic apparatus, is acquired. A second acoustic signal, which is derived from the acoustic signal emitted from the sound emission device and can arrive near an ear of a person or dummy head not wearing the acoustic apparatus, is acquired. The acoustic signal is modulated so as to reduce the change of the first acoustic signal with respect to the second acoustic signal.

Description

Modulation method, modulation system, program

[0001] This disclosure relates to methods, systems, and programs for modulating acoustic signals.

[0002] The provision of Audio Augmented Reality (AAR) experiences, which fuse real-world sounds with virtual sounds to create a 3D audio experience, is becoming more widespread (for example, Non-Patent Documents 1 and 2).

[0003] Non-patent document 1 discloses a technology that provides three-dimensional spatial sound by simultaneously allowing the user to listen to voices and music playing in the venue and acoustic signals emitted from earphones.

[0004] Non-patent document 2 discloses a technology that presents information without disrupting the atmosphere of the venue by allowing users to simultaneously listen to sounds generated in the stadium, the voices of the athletes, and commentary emitted from earphones.

[0005] Nippon Telegraph and Telephone Corporation, “Challenging a New Spatial Sound Production for Super Kabuki Powered by NTT – Realizing a Spatial Sound Production Where Realistic Stage Sounds and Ear-Level Sound Effects Crossover,” [online], April 29, 2023, [Retrieved January 7, 2025], Internet <URL: https: / / group.ntt / jp / newsrelease / 2023 / 04 / 29 / 230429b.html> SPORTS BUSINESS ONLINE, “Sound Brand nwm Expands the Possibilities of Sports,” [online], January 4, 1994, [Retrieved January 7, 2025], Internet <URL: https: / / sportsbusiness.online / 2024 / 01 / 04 / nwm / >

[0006] In prior art, users simultaneously hear sounds emitted from direct sound sources or speakers, as well as sounds emitted from audio devices such as earphones or headphones. However, the transmission characteristics from the direct sound source or speaker to the user's ear canal entrance change depending on whether or not they are wearing audio devices such as earphones or headphones. Because the transmission characteristics modulate the sound from direct sound sources or speakers, there was a problem in that when wearing earphones or headphones, the real-world sound and spatial impression seemed different compared to when they were not.

[0007] Therefore, the purpose of this disclosure is to provide a modulation method that minimizes changes in real-world sound and spatial impression even when audio equipment is worn, compared to when it is not worn.

[0008] The modulation method described herein is performed by a modulation system.

[0009] A first acoustic signal is acquired, which originates from an acoustic signal emitted from a sound-emitting device placed in a predetermined position and may arrive around the ears of a person or dummy head wearing acoustic equipment.

[0010] A second acoustic signal is acquired, which originates from the acoustic signal emitted from the sound-emitting device and may arrive around the ears of a person or dummy head not wearing any acoustic equipment.

[0011] The acoustic signals are modulated to reduce the change in the first acoustic signal relative to the second acoustic signal.

[0012] According to the modulation method of this disclosure, even when wearing audio equipment, there is less change in real-world sounds and spatial impressions compared to when not wearing it.

[0013] A block diagram showing the device configuration of the modulation system of Example 1. A block diagram showing the functional configuration of each device in the modulation system of Example 1. A sequence diagram showing the operation of each device in the modulation system of Example 1. A block diagram showing the device configuration of the modulation system of Modification Example 1. A block diagram showing the functional configuration of each device in the modulation system of Modification Example 1. A sequence diagram showing the operation of each device in the modulation system of Modification Example 1. A block diagram showing the device configuration of the modulation system of Modification Example 2. A block diagram showing the functional configuration of each device in the modulation system of Modification Example 2. A sequence diagram showing the operation of each device in the modulation system of Modification Example 2. A block diagram showing the functional configuration of the modulation section of the modulation system of Modification Example 3. A sequence diagram showing the operation of the modulation section of the modulation system of Modification Example 3. A diagram showing an example of the change in sound energy arriving at the sound insulation material. A diagram showing an example of the functional configuration of a computer.

[0014] The embodiments of the present invention will be described in detail below. Components having the same function will be given the same number, and redundant explanations will be omitted.

[0015] The device configuration of the modulation system of Embodiment 1 will be described below with reference to Figure 1. As shown in the figure, the modulation system 1 of this embodiment includes an acoustic device 9, an acoustic signal acquisition device 11, an acoustic signal correction device 12, and a sound emission device 13.

[0016] If this modulation system 1 is considered as a system that appropriately presents sound from the sound equipment 9 and sound from the sound emission device 13 simultaneously, then it is preferable to include the sound equipment 9 as one of the devices constituting this system.

[0017] However, if we consider this modulation system 1 as a system for modulating acoustic signals, then the acoustic device 9 is a type of object under measurement and does not perform the modulation process itself, so it is not necessary to consider the acoustic device 9 as a device included in this modulation system 1. The details of each device are described below.

[0018] <Audio Device 9> Audio device 9 is a sound-emitting device that can be worn on the human head or elsewhere. Examples include earphones, headphones, neck speakers, headsets, and intercoms. In the case of earphones, in-ear, canal, over-ear, neckband, and open-ear types that do not block the ear canal can all be used as audio device 9. Similarly, in the case of headphones, over-ear, on-ear, and open-ear types can all be used as audio device 9.

[0019] Open-ear earphones and headphones are also called open-ear ear speakers (see Non-Patent Document 1), and open-ear ear speakers can also be used as audio equipment 9.

[0020] (Reference Non-Patent Literature 1: NTT sonority, Inc., “nwm - Official Website / Online Store”, [online], [Retrieved January 7, 2025], Internet <URL: https: / / nwm.global / ?srsltid=AfmBOorX8Pf56giXvsBlW2cUIKzmGsggD0F3s0U8NwET75Fs800hmQqv>) Furthermore, both wired and wireless audio equipment 9 can be used, and both equipment with and without noise-canceling functions can be used.

[0021] As shown in the figure, the sound device 9 is attached to and detached from a person 8 or a dummy head 8 positioned in the sweet spot. If a person 8 is to participate in the measurement, the sound device 9 is attached to and detached from the person 8's head or other part of their body. If a person 8 is to participate in the measurement, this person 8 may be the actual user experiencing the sound effects, or it may be another person.

[0022] As shown in Modification 2 described later, if multiple human beings 8 (or dummy heads 8) are arranged, the same sound equipment 9 may be used for each human being 8 (or each dummy head 8), or different sound equipment 9 may be used.

[0023] <Acoustic signal acquisition device 11> The acoustic signal acquisition device 11 is typically a microphone. A measurement microphone may be used as the acoustic signal acquisition device 11, or a microphone attached to the acoustic device 9 may be used. The acoustic signal acquisition device 11 is preferably configured to be able to acquire sound around the ears of the human 8 (or dummy head 8) (for example, around the entrance of the external auditory canal). The acoustic signal acquisition device 11 is preferably arranged and open around the ears of the human 8 (or dummy head 8) (for example, around the entrance of the external auditory canal). The acoustic signal acquisition device 11 is assumed to be connected communicably to the acoustic signal correction device 12 wirelessly or by wire.

[0024] <Acoustic signal correction device 12> The acoustic signal correction device 12 is a device that obtains a filter from the acoustic signal acquired from the acoustic signal acquisition device 11 and modulates the acoustic signal to be emitted from the sound emitting device 13, and can typically be realized by a general-purpose PC or the like. Note that the modulation of the acoustic signal may be performed in the sound emitting device 13 described later.

[0025] In the present embodiment, the "filter" refers to a broad concept and includes a correction filter, an equalizer, and the like.

[0026] <Sound emitting device 13> The sound emitting device 13 is a device that emits a measurement sound during filter learning and emits an acoustic signal modulated by a filter after filter learning, and is realized by, for example, a speaker.

[0027] Hereinafter, the functional configurations of the respective devices will be described with reference to FIG. 2. As shown in the figure, the acoustic signal acquisition device 11 of the present embodiment includes a first acoustic signal acquisition unit 111 and a second acoustic signal acquisition unit 112. The acoustic signal correction device 12 includes a first acoustic signal acquisition unit 121, a second acoustic signal acquisition unit 122, a filter acquisition unit 123, and a modulation unit 124. The sound emitting device 13 includes an acoustic signal acquisition unit 131 and a sound emitting unit 132. Hereinafter, the operations of the respective functional configurations will be described with reference to FIG. 3.

[0028] The first acoustic signal acquisition unit 111 acquires a first acoustic signal that is derived from the acoustic signal emitted from the sound emitting device 13 arranged at a predetermined position and arrives around the ears of the human 8 or dummy head 8 wearing the acoustic device 9, and transmits it to the acoustic signal correction device 12 (S111).

[0029] Next, the second acoustic signal acquisition unit 112 acquires a second acoustic signal that is derived from the acoustic signal emitted from the sound playback device 13 and arrives around the ears of a human 8 or a dummy head 8 who is not wearing the acoustic device 9, and transmits it to the acoustic signal correction device 12 (S112).

[0030] In steps S111 and S112, the sound emitted from the sound playback device 13 may be any sound, but since it is a test signal, for example, a TSP signal, an exponential chirp signal, etc. may be used, or a sound source that is actually planned to be played back by the user may be used.

[0031] The first acoustic signal acquisition unit 121 of the acoustic signal correction device 12 acquires the first acoustic signal (S121). The second acoustic signal acquisition unit 122 acquires the second acoustic signal (S122).

[0032] The filter acquisition unit 123 acquires a filter that reduces the change of the first acoustic signal with respect to the second acoustic signal (S123). Hereinafter, the filter acquired in step S123 will be described.

[0033] The transfer characteristic of the right ear from the sound playback device 13 to the entrance of the external auditory canal when the acoustic device 9 is worn is represented by H , wo , w , wo,BRTF , tp , w,BRTF , tp , , R , R , R , R , R , R , R w,BRTF (s, p, f), and the transfer characteristic of the right ear from the sound playback device 13 to the entrance of the external auditory canal when the acoustic device 9 is not worn is represented by H R wo,BRTF (s, p, f), and the sound emitted from the sound playback device 13 is represented by X(f). Here, s is a parameter representing the physical characteristics of the listener (the shape of the body such as the head, ears, and torso), and p is a parameter representing the position of the listener and the orientation of the listener's face. The right ear listening sound Y R w (f), and the right ear listening sound Y R wo (f) are respectively represented by the following equations. Therefore, the acoustic permeability H R tp (f) is represented by the following equation. The filter C R tp (f) for the right ear is the acoustic permeability H Rtp Since it is the reciprocal of (f), it can be expressed by the following formula. Filter C for the left ear L tp (f) is calculated similarly. The combined filter C is formed by combining the filters for the left and right ears. tp (f) is expressed by the following formula. In the above equation, if there is only one sound-emitting device 13 and it is not biased to the left or right, such as in front or behind, the left and right filters may be averaged and used as an integrated filter. If there is only one sound-emitting device 13 and it is positioned closer to either the left or right side, the filter on the closer side may be used as the integrated filter. Since the same filter is used to correct the left and right received sounds, this is particularly suitable when the sound source is in the direction of the listener's midline (for example, in front or behind).

[0034] The sound Y received in the right ear is the sound modulated based on the above filter and emitted from the sound emission device 13. R c (f) The sound Y received in the left ear L c (f) is expressed by the following equation, and each is Y R wo (f), Y L wo This will be an approximate value of (f). As described above, the filter detects the sound Y when the audio device 9 is attached. w (f) The sound Y received when the audio device 9 is not attached. wo (f) can also be used to determine this, but it is also possible to determine it from the transmission characteristics from the sound emission device 13 to the entrance of the external auditory canal. For example, the transmission characteristics H required for calculating acoustic transmission w,BRTF (s,p,f), H wo,BRTF The impulse response of (s,p,f) can be measured in an anechoic chamber.

[0035] If the characteristics of a room such as an anechoic chamber, including reflections and reverberation, are not included, H w , H wo H w,HRTF (s,θ,φ,d,f), H wo,HRTF It can also be expressed as (s,θ,φ,d,f). Here, θ is the horizontal angle of the sound source, φ is the upward angle of the sound source, and d is the distance. That is, Hwo This is the head-related transfer function.

[0036] In this case, the dummy head 8 is placed in an anechoic chamber, the acoustic signal acquisition device 11 is placed at the entrance of the ear canal of the dummy head 8, the acoustic equipment 9 is attached to the dummy head 8, and the sound emission device 13 is placed in front of the dummy head 8.

[0037] As a method for obtaining a filter from the impulse response of the transfer characteristics, one can apply a Kaiser window to the impulse response, perform an FFT, and then calculate the inverse characteristics by dividing by the frequency domain as described above to obtain the impulse response of the filter.

[0038] As a method for obtaining a filter from the impulse response of the transfer characteristics, one can apply a Kaiser window to the impulse response, perform an FFT, divide by the amplitude spectrum to calculate the inverse amplitude characteristic, calculate the minimum phase filter using the Hilbert transform, reconstruct the transfer function, and perform an inverse FFT to obtain the impulse response of the filter.

[0039] Next, the modulation unit 124 of the acoustic signal correction device 12 modulates the acoustic signal emitted from the sound emitter 13 based on the filter acquired in step S123 (S124). Alternatively, the modulation unit 124 may be provided in the sound emitter 13, and the sound emitter 13 may perform the modulation process. In this case, the acoustic signal correction device 12 transmits the filter acquired in step S123 to the sound emitter 13, and the sound emitter 13 executes step S124 based on the received filter. [Modification Example 1]

[0040] The following describes a modulation system 1A (modification 1) in which there are multiple sound-emitting devices 13, with reference to Figure 4. As shown in the figure, in this modification, there are a total of t sound-emitting devices 13 (t is an integer of 2 or more), and each sound-emitting device is referred to as sound-emitting device 13-1, ..., 13-t. As shown in the figure, examples of sound-emitting devices 13 surrounding the listener include a 2.1ch stereo speaker with t=2, a 5.1ch surround speaker with t=5, and a 7.1.2ch surround speaker with t=9. Although the subwoofer, represented as "...1", is not counted as a sound-emitting device 13, it may be counted as one of the sound-emitting devices 13.

[0041] In this modified example, the acoustic signal acquisition device 11 of Example 1 is replaced with an acoustic signal acquisition device 11A, and the acoustic signal correction device 12 of Example 1 is replaced with an acoustic signal correction device 12A.

[0042] As shown in Figure 5, the acoustic signal acquisition device 11A includes a first acoustic signal acquisition unit 111A and a second acoustic signal acquisition unit 112A. The acoustic signal correction device 12A includes a first acoustic signal acquisition unit 121A, a second acoustic signal acquisition unit 122A, a filter acquisition unit 123A, and a modulation unit 124A. The sound emission device 13 has the same functions as in Embodiment 1, but differs from Embodiment 1 in that there are a total of t units.

[0043] The functional configurations of the acoustic signal acquisition device 11A and the acoustic signal correction device 12A are generally the same as those in Embodiment 1, but as shown in Figure 6, steps S111, S112, S121, S122, S123, and S124 are performed for each of the sound emission devices 13-1, ..., 13-t (corresponding to the branch numbers of the sound emission devices 13, each process is expressed as S111-1, ..., t, S112-1, ..., t, ..., etc.). The only difference from Embodiment 1 is that these processes modulate the acoustic signals emitted from each of the sound emission devices 13-1, ..., 13-t using different filters.

[0044] Typically, modulation can be performed based on filters determined for each sound emitter 13-1, ..., 13-t. However, alternatively, the positions of the sound emitters 13 may be grouped into multiple directions such as front, back, left, and right, and modulation may be performed for each group based on filters suitable for that group's modulation. Alternatively, the average value of the filters determined for each sound emitter 13-1, ..., 13-t may be used for the modulation of all sound emitters 13-1, ..., 13-t. Furthermore, the filters determined for each sound emitter 13-1, ..., 13-t may be mixed and used in an appropriate manner, taking into account their characteristics.

[0045] Similar to Example 1, each sound emission device 13-1, ..., 13-t may perform modulation processing. [Modification 2]

[0046] The following describes a modulation system 1B (modification 2) when multiple people (or multiple dummy heads 8) are arranged, with reference to Figure 7. As shown in the figure, in this modification, there are a total of k people (or k dummy heads 8, where k is an integer greater than or equal to 2), and the people 8 (or dummy heads 8) are numbered 8-1, ..., 8-k. There are k acoustic signal acquisition devices 11, corresponding to the number of people (or dummy heads 8) (or k pairs, left and right, if the acoustic signal acquisition devices 11 are placed on each ear), and each is numbered 11-1, ..., k.

[0047] As shown in Figure 8, the acoustic signal acquisition devices 11-1, ..., k are the same as the acoustic signal acquisition device 11 in Embodiment 1. The acoustic signal correction device 12B includes a first acoustic signal acquisition unit 121B, a second acoustic signal acquisition unit 122B, a filter acquisition unit 123B, and a modulation unit 124B. The sound emission device 13 is the same as in Embodiment 1.

[0048] As shown in Figure 9, each acoustic signal acquisition device 11-1, ..., k performs steps S111 and S112 in the same manner as in Embodiment 1 (each process is expressed as S111-1, ..., k, S112-1, ..., k, ..., etc., corresponding to the branch number).

[0049] The acoustic signal correction device 12B performs the modulation process in step S124B based on one of the filters obtained by performing steps S121 to S123 for each human 8 or each dummy head 8 (S121-1, ..., k, S122-1, ..., k, S123-1, ..., k), or based on a filter obtained by performing statistical processing on the obtained filters.

[0050] As a statistical process, for example, all acquired filters may be averaged, or specific filters may be weighted before averaging. When weighting, the hearing ability of humans may be taken into consideration. For example, weighting may be applied to prioritize the correction of transparency for people with good hearing and who are sensitive to the deterioration of transparency.

[0051] [Modification 3] Hereinafter, a modulation system 1C (Modification 3) using a crossover network will be described with reference to Figure 10. Since the functional configuration of the modulation system 1C in this modification is the same as in Embodiment 1 except for the modulation section, the figures other than the modulation section have been omitted. As shown in the figure, the modulation section 124C of the acoustic signal correction device 12C in this modification includes a low-pass filter section 1241, a high-pass filter section 1242, a modulation section 1243, a delay / phase compensation filter section 1244, and a signal synthesis section 1245.

[0052] As shown in Figure 11, the low-pass filter section 1241 performs low-pass filtering on the acoustic signal (S1241), and the high-pass filter section 1242 performs high-pass filtering on the acoustic signal (S1242). Butterworth and Linkwitz-Riley filters are commonly used as low-pass / high-pass filters in crossover networks.

[0053] The cutoff frequency fc of the low-pass / high-pass filter is preferably set to around 4kHz, for example, considering the small individual differences in HRTF (ear shape).

[0054] The modulation unit 1243 modulates the acoustic signal, which has been filtered using a low-pass filter, with a filter that corrects acoustic transparency, similar to the first embodiment (S1243). In this embodiment, since the modulation process is performed using a combination of a crossover network filter and a filter that corrects acoustic transparency, the modulation process may be performed in S1243 only for a specific frequency band. For example, a frequency band of 4kHz or less where the effect of the HRTF is small, or 10kHz or less where the effect of the mounting position is small, can be considered.

[0055] The delay / phase compensation filter section 1244 performs filtering to compensate for delay and phase in the high-pass filtered acoustic signal (S1244). The delay / phase compensation filter section 1244 can utilize an all-pass filter with phase characteristics approximately equal to those of the filter in step S1243. The delay / phase compensation filter section 1244 can be omitted if the filter in step S1243 has minimum phase. If the filter in step S1243 does not have minimum phase, a pure delay circuit can be used to match the delay (timing) of the filter in step S1243.

[0056] The signal synthesis unit 1245 synthesizes the acoustic signal obtained by performing low-pass filtering in step S1241 and acoustic transparency correction filtering in step S1243, and the acoustic signal obtained by performing high-pass filtering in step S1242 and delay / phase compensation filtering in step S1244, and transmits it to the sound emission device 13 (S1245).

[0057] As shown in Figure 12, the original sound energy E depends on the sound insulation material of the sound device 9 worn by the user. l Reflected energy E r Energy E absorbed as heat a Energy E that escapes to the back t It is known that they are different.

[0058] Therefore, modulation may be performed based on the shape and / or material of the sound device 9 worn by the user. More specifically, it is preferable to perform the modulation based on the shape and / or material that affects the sound insulation and sound absorption characteristics. For example, it may be based on the thickness of the structure, the structure connecting the inside and outside of the sound device 9, or the characteristics of the material of each structure itself. It may also be based on the proportion that the structure covers the ear. More specifically, the reflected energy E when sound waves from the sound source arrive at the structure. r And, energy E transmitted towards the user via the structure. t And the energy E absorbed by the structure a You should take that into consideration.

[0059] Furthermore, the filter learning and modulation by the filter in the above embodiments and modifications do not necessarily have to be performed in the same space, as shown in Figures 1, 4, and 7, for example; they may be performed in separate spaces. In that case, the relationship between the human 8 and the sound emission device 13 can be considered to be approximately the same during learning and modulation, that is, the s and p in the above-mentioned mathematical formulas can be considered to be approximately the same.

[0060] Filter learning may be performed in advance at a time separate from the modulation process. Therefore, assuming a modulation system (modulation method) that only performs modulation, the first and second acoustic signals are not observed in that system (method). Therefore, from the perspective of that system (method), the first acoustic signal can also be described as a signal that originates from the acoustic signal emitted from the sound emission device 13 and "may" arrive around the ear of a person 8 or dummy head 8 wearing the acoustic device 9. Similarly, the second acoustic signal can also be described as a signal that originates from the acoustic signal emitted from the sound emission device 13 and "may" arrive around the ear of a person 8 or dummy head 8 not wearing the acoustic device 9.

[0061] <Effects> According to the modulation system and modulation method disclosed in the above-described embodiments and modifications, it is possible to reproduce a sound that is similar to that when the sound device 9 is not worn, even when the sound device 9 is worn. This makes it possible to provide an AAR experience in which virtual sounds emitted from the sound device 9 are superimposed on real-world sounds that are similar to how they are heard when the sound device 9 is not worn.

[0062] Furthermore, the device (terminal) may also be used for using the device, system, or method of disclosure via a network (telecommunication line). The "device (terminal) for use" may be equipped with functions necessary to obtain the effects of implementing the device, system, or method of disclosure (e.g., control functions, decoding functions, restoration functions, input / output functions, etc.).

[0063] [Processors, Programs, Recording Media] The functions realized by the components described herein may be implemented in a circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), CPUs (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to realize the functions described herein. A processor includes transistors and other circuits and is considered a circuitry or processing circuitry. A processor may be a programmed processor that executes a program stored in memory.

[0064] In this specification, circuitry, unit, and means are hardware programmed to perform or execute the functions described herein. Such hardware may be any hardware disclosed herein, or any hardware known to be programmed to perform or execute the functions described herein.

[0065] If the hardware is a processor that is considered to be a type of circuitry, then the circuitry, means, or unit is a combination of hardware and software used to constitute the hardware and / or processor.

[0066] The various processes described above can be carried out by loading a program that executes each step of the above method into the recording unit 10020 of the computer 10000 shown in Figure 13, and then causing the control unit 10010, input unit 10030, output unit 10040, display unit 10050, etc. to operate.

[0067] The program describing this process can be recorded on a computer-readable recording medium. Any computer-readable recording medium can be used, such as a magnetic recording device, optical disc, magneto-optical recording medium, or semiconductor memory.

[0068] A program describing this process may be included in a computer program product.

[0069] Furthermore, this program may be distributed, for example, by selling, transferring, or lending portable recording media such as DVDs or CD-ROMs on which the program is recorded. Alternatively, the program may be stored in the storage device of a server computer and distributed by transferring the program from the server computer to other computers via a network.

[0070] A computer executing such a program may, for example, first store the program recorded on a portable storage medium or a program transferred from a server computer in its own storage device. Then, when processing is to be executed, the computer reads the program stored on its own storage medium and executes the processing according to the read program. Alternatively, the computer may directly read the program from the portable storage medium and execute the processing according to that program, or it may sequentially execute the processing according to the received program each time a program is transferred to it from a server computer. Furthermore, the processing may be executed using a so-called ASP (Application Service Provider) type service, where the processing function is realized only by issuing execution instructions and obtaining results, without transferring the program from the server computer to this computer.In addition, the processing may be executed using a so-called SaaS (Software as a Service) type service, where a part of the server computer is made available to the user along with the program. Furthermore, the term "program" in this form includes information used for processing by an electronic computer that is equivalent to a program (data, etc., that is not a direct instruction to the computer but has the property of defining the processing of the computer).

[0071] Furthermore, in this configuration, the device is configured by executing a predetermined program on a computer, but at least a part of these processes may be implemented in hardware.

Claims

1. A modulation method performed by a modulation system, comprising: acquiring a first acoustic signal originating from an acoustic signal emitted from a sound-emitting device positioned at a predetermined location and which may arrive around the ears of a person or dummy head wearing an acoustic device; acquiring a second acoustic signal originating from the acoustic signal emitted from the sound-emitting device and which may arrive around the ears of a person or dummy head not wearing the acoustic device; and modulating the acoustic signals such that the change in the first acoustic signal relative to the second acoustic signal is reduced.

2. The modulation method according to claim 1, wherein the modulation is performed by a filter, and the filter is obtained based on the relationship between the position of the human or the dummy head and the position of the sound emission device.

3. The modulation method according to claim 2, wherein the modulation is performed based on the shape and / or material of the sound equipment.

4. A modulation system comprising an acoustic signal acquisition device, an acoustic signal correction device, and a sound emission device, wherein the acoustic signal acquisition device acquires a first acoustic signal originating from an acoustic signal emitted from the sound emission device positioned at a predetermined location and arriving around the ears of a person or dummy head wearing an acoustic device, and acquires a second acoustic signal originating from an acoustic signal emitted from the sound emission device and arriving around the ears of a person or dummy head not wearing the acoustic device, and the acoustic signal correction device modulates the acoustic signal to reduce the change in the first acoustic signal relative to the second acoustic signal.

5. A program for causing a computer to perform the modulation method described in claim 1.

Images