Acoustic processing device, acoustic processing method, and acoustic processing program

Abstract

Provided is an acoustic processing device comprising: an acquisition unit that acquires an outside acoustic signal that is a signal derived from acoustics propagating outside the external auditory canal of a user and an inside acoustic signal that is a signal derived from acoustics propagating inside the external auditory canal; a hearing aid processing unit that adjusts the sound volume of the outside acoustic signal on the basis of the auditory characteristics of the user measured in advance; an adjustment unit that, on the basis of the adjustment amount of the sound volume of the outside acoustic signal by the hearing aid processing unit, adjusts an occlusion cancellation amount for attenuating an occlusion that causes the sound volume of the inside acoustic signal to be amplified due to wearing of an acoustic device on an ear of the user; and an output unit that outputs, to the user, an output sound with which the sound volume of the outside acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit.

Description

Sound processing device, sound processing method, and sound processing program

[0001] The present disclosure relates to a sound processing device, a sound processing method, and a sound processing program.

[0002] When a user wears an acoustic device such as an earphone or a hearing aid, the entrance to the user's ear canal is sealed by the acoustic device. When the user speaks in this state, the volume of the internal acoustic signal, which is an acoustic signal derived from the sound propagating inside the ear canal, is amplified, resulting in a so-called occlusion effect (hereinafter simply referred to as "occlusion"). The user may feel uncomfortable because the sound they produce sounds different from normal due to the occlusion.

[0003] As a technique for reducing such discomfort felt by the user, a technique for performing occlusion cancellation is known.

[0004] Patent No. 6604376

[0005] In conventional technology, occlusion cancellation is achieved by suppressing the volume of the frequency corresponding to the user's own voice toward a state in which the audio device is not worn.

[0006] However, conventional technologies are not designed to provide a function that makes it easier for users to hear sounds that are difficult for users to hear. Therefore, there is a need for a technology that makes it easier for users to hear sounds that are difficult for users to hear while reducing the discomfort felt by users.

[0007] Therefore, the present disclosure proposes a sound processing device, a sound processing method, and a sound processing program that make it easier for a user to hear sounds that are difficult for the user to hear while reducing discomfort to the user.

[0008] According to the present disclosure, there is provided a sound processing device comprising: an acquisition unit that acquires an outer acoustic signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid processing unit that adjusts the volume of the outer acoustic signal based on the hearing characteristics of the user that have been measured in advance; an adjustment unit that adjusts an occlusion cancellation amount, which is an amount by which occlusion that is amplified when the sound device is worn on the user's ear, is attenuated, based on the amount of adjustment of the volume of the outer acoustic signal by the hearing aid processing unit; and an output unit that outputs to the user an output sound in which the volume of the outer acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit.

[0009] 1 is a diagram showing a schematic configuration of a hearing aid system 1 according to an embodiment. FIG. 2 is a block diagram of a hearing aid 2 and a charger 3 according to an embodiment. FIG. 3 is a block diagram of an information processing device 40 according to an embodiment. FIG. 4 is a block diagram of a hearing aid 2 according to a first embodiment. FIG. 5 is a diagram for explaining an example of a hearing aid processing unit 212. FIG. 6 is a diagram for explaining an example of speech enhancement processing. FIG. 7 is a diagram for explaining an example of hearing correction processing. FIG. 8 is a graph showing a target value of the amount of occlusion cancellation for each frequency. FIG. 9 is a graph showing an expected amount of cancellation of a designed filter for each frequency. FIG. 10 is a graph showing a target value of the amount of occlusion cancellation, an expected amount of cancellation of a designed filter, and an adjusted expected amount of cancellation for each frequency. FIG. 11 is a flowchart of adjustment of acoustic processing according to the first embodiment. FIG. 12 is a flowchart of operation of acoustic processing according to the first embodiment. FIG. 13 is a block diagram of a hearing aid 2a according to a second modified example of the first embodiment. FIG. 14 is a block diagram of a hearing aid 2b according to a third modified example of the first embodiment. FIG. 15 is a block diagram of a hearing aid 2c according to a second embodiment. FIG. 16 is a block diagram of a hearing aid 2d according to a modified example of the second embodiment. FIG. 17 is a diagram for explaining an example of a howling cancellation filter of a howling cancellation unit 212A. FIG. 10 is a block diagram of a hearing aid 2e according to a third embodiment. FIG. 11 is a diagram for explaining an example of a separation section 225. FIG. 12 is a block diagram of a hearing aid 2f according to a fourth embodiment. FIG. 13 is a diagram for explaining an example of a hearing aid processing section 212f. FIG. 14 is a flowchart for adjusting sound processing according to the fourth embodiment. FIG. 15 is a flowchart for the operation of sound processing according to the fourth embodiment. FIG. 16 is a block diagram of a hearing aid 2g according to a modified example of the fourth embodiment. FIG. 17 is a diagram for explaining an example of a hearing aid processing section 212g. FIG. 18 is a graph showing the amount of suppression of the own voice signal for each frequency. FIG. 19 is a hardware configuration diagram showing an example of a computer that realizes the functions of a hearing aid 2 according to an embodiment.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. In the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0011] The present disclosure will be described in the following order: 1. Overview of hearing aid system 1 2. Details of hearing aid system 1 3. First embodiment 3.1 Hearing aid 2 3.2 Acoustic processing method 3.3 Modified example 4. Second embodiment 4.1 Hearing aid 2c 4.2 Modified example 5. Third embodiment 6. Fourth embodiment 6.1 Hearing aid 2f 6.2 Acoustic processing method 6.3 Modified example 7. Other embodiments 8. Effects of the sound processing device according to the present disclosure 9. Hardware configuration 10. Supplementary information

[0012] <<1. Overview of Hearing Aid System 1>> An overview of a hearing aid system 1 according to an embodiment will be described with reference to Figures 1 to 3. Figure 1 is a diagram showing the schematic configuration of a hearing aid system 1 according to an embodiment. Figure 2 is a block diagram of a hearing aid (acoustic device, sound processing device) 2 and a charger 3 according to an embodiment. Figure 3 is a block diagram of an information processing device (sound processing device) 40 according to an embodiment.

[0013] The hearing aid system 1 will be described below using as an example a case where the acoustic device and the acoustic processing device are binaural hearing aids 2 worn on both the left and right ears. However, the acoustic device is not limited to this example and may be a monoaural device worn on either the left or right ear, or may be an earphone, a headphone, etc. Furthermore, the acoustic processing device may be the same as the acoustic device, or may be a different device from the acoustic device, such as an information processing device such as a terminal or a server.

[0014] In Figure 1, the hearing aid system 1 of the embodiment includes a pair of hearing aids 2 (left and right), a charger 3 that stores and charges the hearing aids 2, and an information processing device 40 such as a terminal such as a smartphone that can communicate with at least one of the hearing aids 2 and the charger 3.

[0015] The hearing aid 2 is worn in the ear of a user. In Fig. 2, the hearing aid 2 includes an acquisition unit 20, a signal processing unit 21, an output unit 22, a battery 23, a connection unit 24, a communication unit 25, a memory unit 26, a control unit 27, and a communication unit 28.

[0016] The acquisition unit 20 includes an outer sound collection unit 20f that acquires an outer acoustic signal, which is an acoustic signal derived from sound propagating outside the user's ear canal, and an inner sound collection unit 20b that acquires an inner acoustic signal.

[0017] The outer sound collection unit 20f and the inner sound collection unit 20b each include a microphone 201 and an A / D (analog / digital) conversion unit 202. The microphone 201 collects sound from the outside or inside of the ear canal, generates an analog acoustic signal from the sound, and outputs the analog acoustic signal to the A / D conversion unit 202. The A / D conversion unit 202 performs digital conversion processing on the analog acoustic signal input from the microphone 201 to obtain an outer acoustic signal or an inner acoustic signal, which is a digitized acoustic signal, and outputs the outer acoustic signal or the inner acoustic signal to the signal processing unit 21.

[0018] The "outer acoustic signal" is not limited to an acoustic signal input to the microphone 201f outside the user's ear canal, but includes, for example, an acoustic signal obtained by applying predetermined processing to the outer acoustic signal. The "inner acoustic signal" is not limited to an acoustic signal input to the microphone 201b inside the user's ear canal, but includes, for example, an acoustic signal obtained by applying predetermined processing to the inner acoustic signal.

[0019] The signal processing unit 21 is configured with a memory and a processor having hardware such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor). The signal processing unit 21 performs signal processing on the digital acoustic signal input from the acquisition unit 20 and outputs the signal to the output unit 22.

[0020] The signal processing includes filtering processing that separates acoustic signals by frequency, howling cancellation processing that suppresses howling, voice enhancement processing that emphasizes the acoustic signals that the user wants to hear, and hearing correction processing that adjusts the volume of external acoustic signals based on the user's hearing characteristics that have been measured in advance.

[0021] The above and hereinafter "every frequency" is not limited to meaning every 1 Hz, but also includes meanings of every predetermined frequency interval such as 500 Hz, 1000 Hz, 2000 Hz, etc., and every predetermined frequency band such as 500 Hz or more and 1000 Hz or less, or 1000 Hz or more and 2000 Hz or less.

[0022] The output unit 22 includes a D / A (digital / analog) conversion unit 221 and a receiver 222. The D / A conversion unit 221 performs analog conversion processing on the digital acoustic signal input from the signal processing unit 21 and outputs the signal to the receiver 222. The receiver 222 is a speaker. The receiver 222 generates output sound from the analog acoustic signal input from the D / A conversion unit 221. The receiver 222 then outputs the output sound.

[0023] The battery 23 is a rechargeable secondary battery such as a lithium ion battery. The battery 23 supplies power to each component of the hearing aid 2. The battery 23 is charged by power supplied from the charger 3 via the connection unit 24.

[0024] The connection unit 24 is one or more pins. When the hearing aid 2 is stored in the charger 3, the connection unit 24 connects to the connection unit 331 of the charger 3, receives power and various information from the charger 3, and outputs various information to the charger 3.

[0025] The communication unit 25 is a communication module that communicates with the charger 3 and the information processing device 40 via a communication network in accordance with a communication standard such as Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0026] The storage unit 26 is a RAM (Random Access Memory), a ROM (Read Only Memory), or a memory card. The storage unit 26 stores various information related to the hearing aid 2. The storage unit 26 stores a program 261 executed by the hearing aid 2, and data 262 such as the user's age, whether or not they have used the hearing aid 2 before, their gender, and the length of time they have used the hearing aid 2.

[0027] The control unit 27 is composed of a memory and a processor having hardware such as a CPU and a DSP. The control unit 27 controls each part of the hearing aid 2. The control unit 27 reads a program 261 into a working area of ​​the memory and executes it, and controls each part through the execution of the program 261 by the processor.

[0028] The communication unit 28 is a communication module that communicates with the other hearing aid 2 by short-range communication such as NFMI (Near Field Magnetic Induction).

[0029] The hearing aid 2 may further include an operation unit (not shown). The operation unit is a push-button switch, a button, or a touch panel. The operation unit receives input signals for operating the hearing aid 2 and outputs the signals to the control unit 27.

[0030] In FIG. 2 , the charger 3 includes a display unit 31 , a battery 32 , a storage unit 33 , a communication unit 34 , a storage unit 35 , and a control unit 36 ​​.

[0031] The display unit 31 is a light-emitting diode (LED). The display unit 31 displays various types of information. The display unit 31 displays information indicating that the hearing aid 2 is being charged and information indicating that various types of information are being received from the information processing device 40.

[0032] The battery 32 is a secondary battery such as a lithium ion battery. The battery 32 supplies power to the hearing aid 2 and the charger 3 housed in the housing 33 via a connection 331 provided in the housing 33.

[0033] When the hearing aid 2 has two channels, left and right, the storage unit 33 stores each of them separately. The storage unit 33 is provided with a connection unit 331 that can be connected to the connection unit 24 of the hearing aid 2. The connection unit 331 is one or more pins. When the hearing aid 2 is stored in the storage unit 33, the connection unit 331 connects to the connection unit 24 of the hearing aid 2, and transmits power from the battery 32 and various information from the control unit 36, as well as receiving various information from the hearing aid 2 and outputting it to the control unit 36.

[0034] The communication unit 34 is a communication module that communicates with the information processing device 40 via a communication network in accordance with a communication standard such as Wi-Fi or Bluetooth.

[0035] The storage unit 35 is a RAM, a ROM, a flash memory, or a memory card. The storage unit 35 stores a program 351 to be executed by the charger 3.

[0036] The control unit 36 ​​is composed of a memory and a processor having hardware such as a CPU and a DSP. The control unit 36 ​​controls each part of the charger 3. When the hearing aid 2 is stored in the storage unit 33, the control unit 36 ​​supplies power from the battery 32 via the connection unit 331. The control unit 36 ​​reads and executes a program 351 into a working area of ​​the memory, and controls each part through the execution of the program 351 by the processor.

[0037] In FIG. 3, the information processing device 40 includes an input unit 41, a communication unit 42, an output unit 43, a display unit 44, a storage unit 45, and a control unit 46.

[0038] The input unit 41 is a switch or a touch panel, and receives various operations from the user and outputs a signal corresponding to the received operation to the control unit 46.

[0039] The communication unit 42 is a communication module that communicates with the charger 3 or the hearing aid 2 via a communication network.

[0040] The output unit 43 is a speaker that outputs an output sound at a volume set for each frequency.

[0041] The display unit 44 is a liquid crystal display or an organic EL (Electroluminescence) display, and displays various information related to the information processing device 40 and the hearing aid 2.

[0042] The storage unit 45 is a recording medium such as a RAM, a ROM, a flash memory, a memory card, etc. The storage unit 45 stores various information related to the information processing device 40, a program 451 executed by the information processing device 40, and the like.

[0043] The control unit 46 is composed of a memory and a processor having hardware such as a CPU and a DSP. The control unit 46 controls each unit of the information processing device 40. The control unit 46 reads a program 451 stored in the storage unit 45 into a working area of ​​the memory, executes the program, and controls each unit through the execution of the program 451 by the processor.

[0044] <<2. Details of Hearing Aid System 1>> Details of the hearing aid system 1 according to the embodiment will be described. The purpose of the hearing aid system 1 is to reduce discomfort to the user while maintaining its original function of making sounds of difficult-to-hear frequencies easier to hear. To achieve this purpose, the hearing aid system 1 performs acquisition processing, hearing aid processing, adjustment processing, and output processing.

[0045] (Acquisition process) The hearing aid system 1 acquires an outside acoustic signal and an inside acoustic signal. As the outside acoustic signal, the hearing aid system 1 acquires a voice signal of the user or another person, an output sound signal of the output sound output from the output unit 22, and an acoustic signal of noise such as environmental sound. As the inside acoustic signal, the hearing aid system 1 acquires an outside-originating acoustic signal which is an acoustic signal originating from the outside among the inside acoustic signals and including an acoustic signal of noise leaking in from the outside, and an inside-originating acoustic signal which is an acoustic signal originating from the inside among the inside acoustic signals and including an own voice signal which is a signal of the user's own voice.

[0046] (Hearing Aid Processing) The hearing aid system 1 adjusts the volume of the outside acoustic signal based on the user's hearing characteristics that have been measured in advance. "Hearing characteristics" refer to the ease with which the user can hear sounds at each frequency.

[0047] Since hearing characteristics differ from user to user, it is not linear, such as the higher the frequency of sound being more difficult for the user to hear. For this reason, the hearing aid system 1 adjusts the amplification amount of the external sound signal so that the amplification amount varies for each frequency based on the user's hearing characteristics. The parameters that determine the amplification amount for each frequency and other behavior in this process are called "hearing correction setting values."

[0048] For example, if an audiogram, which is a graph showing the ease with which a user hears sounds for each frequency, indicates that the user cannot hear low-frequency sounds, the hearing aid system 1 determines that the user has difficulty hearing low-frequency sounds. In this case, the hearing aid system 1 amplifies the volume of low-frequency sounds. Similarly, if the hearing aid system 1 determines that the user can hear high-frequency sounds at the same level as a person with normal hearing, it does not amplify the volume of high-frequency sounds.

[0049] (Adjustment Process) The hearing aid system 1 adjusts the amount of occlusion cancellation, which is the amount by which occlusion is attenuated, based on the amount by which the volume of the outside acoustic signal is adjusted by the hearing aid process.

[0050] "Occlusion cancellation" is a process that attenuates the volume of specific frequencies in the output sound signal in order to eliminate discomfort caused by the amplification of the volume of the internal sound signal. Because the hearing aid system 1 performs hearing aid processing based on the hearing characteristics as described above, simply performing occlusion cancellation with a preset occlusion cancellation amount could cause problems with the hearing aid processing. For this reason, the hearing aid system 1 adjusts the occlusion cancellation amount based on the user's hearing characteristics.

[0051] Details of this processing will be described later, but as an example, let's assume that the amount of amplification of the volume of an outer acoustic signal at a predetermined frequency by the hearing aid processing is X dB, and the amount of occlusion at this time is 20 dB. In this case, the user will simultaneously hear two sounds in their ears: sound amplified by X dB by the hearing aid processing, and sound amplified by 20 dB by occlusion. Note that the "amount of occlusion" refers to the amount of amplification of the volume of the inner acoustic signal amplified by wearing the hearing aid 2 in the user's ear.

[0052] If X dB ≥ 20 dB, the user will feel that their own voice is amplified by X dB due to the characteristics of the sound. In this case, even if occlusion cancellation is performed and the amount of occlusion is reduced to 10 dB or 0 dB, the user will still hear sound that has been amplified by X dB through hearing aid processing, so the user's bodily sensation will remain almost unchanged. In other words, in such a case, there is no point in increasing the amount of occlusion cancellation through information processing.

[0053] On the other hand, if XdB<20dB, the user will be more affected by occlusion than by hearing aid processing, and will hear as if only their own voice has been amplified by 20dB. However, the user would actually want to hear sound with the level of difficult-to-hear frequencies amplified by XdB, and having only their own voice amplified by 20dB results in a result that is contrary to the intended function of the hearing aid 2.

[0054] Therefore, in such a case, the hearing aid system 1 adjusts the amount of occlusion cancellation so that the amount of occlusion, 20 dB, is equal to or less than X dB, which is the amplification amount of the volume of the outside acoustic signal.

[0055] Thereafter, as an output process, the hearing aid system 1 outputs to the user an output sound in which the volume of the outside acoustic signal and the amount of occlusion cancellation have been adjusted by the hearing aid process and the adjustment process.

[0056] In this way, the hearing aid system 1 adjusts the amount of occlusion cancellation based on the amount of adjustment of the volume of the outside acoustic signal by the hearing aid processing. This allows the hearing aid system 1 to suppress sounds such as the user's own voice that are overly amplified in the ear and that the user does not want to hear, while allowing the user to hear sounds that have been amplified at a level that the user finds difficult to hear, thereby reducing the user's discomfort and making sounds that the user finds difficult to hear easier to hear.

[0057] <<3. First embodiment>> <3.1 Hearing aid 2> Next, the hearing aid 2 according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a block diagram of the hearing aid 2 according to the first embodiment.

[0058] The hearing aid 2 in Fig. 4 comprises an acquisition unit 20 having additional functions in addition to those described with reference to Fig. 2, a signal processing unit 21, and an output unit 22. The other components of the hearing aid 2 in Fig. 4 have the same functions as those described with reference to Fig. 2, and therefore their description will be omitted.

[0059] (Acquisition Unit 20) The acquisition unit 20 in FIG. 4 functions as the outer sound collection unit 20f and the inner sound collection unit 20b of the acquisition unit 20 in FIG. 2, and also functions as a processor or the like that further acquires the user's hearing characteristics and the amount of occlusion.

[0060] The acquisition unit 20 acquires the hearing characteristics of the user. The hearing characteristics are, for example, information in a format called an audiogram, and are obtained based on the user's responses to a hearing test such as a hearing test to determine whether the user can hear sounds of various pitches and volumes.

[0061] The acquisition unit 20 acquires a hearing correction setting value based on the acquired hearing characteristics. The hearing correction setting value is a value obtained from a predetermined calculation formula called a prescription formula based on the hearing characteristics, etc., or is a value obtained from the prescription formula and adjusted by, for example, an audiologist, who is an expert in hearing, based on counseling, etc.

[0062] Specifically, when an audiologist or the like inputs into the information processing device 40 as a setting value the numerical value obtained by calculation using a prescription formula from the hearing characteristics obtained using a dedicated application, or a numerical value related to hearing aid processing obtained by further adjusting that numerical value, the acquisition unit 20 acquires the setting value as the hearing correction setting value via the communication unit 25.

[0063] 4, the acquisition unit 20 indirectly acquires the hearing correction setting value from the information processing device 40. However, instead of the acquisition unit 20, an application dedicated to audiologists installed in the control unit 46 of the information processing device 40, such as a smartphone, can calculate and set the hearing correction setting value, thereby directly acquiring the hearing correction setting value.

[0064] The acquisition unit 20 acquires, as the amount of occlusion, the amplification amount of the peak corresponding to the peak of the acoustic spectrum of the self-voice signal amplified by wearing the hearing aid 2. Specifically, the "peak" is the volume of the acoustic signal corresponding to the peak of the acoustic spectrum having a sawtooth shape (harmonic structure) with peaks at the fundamental frequency and its integer multiple frequencies.

[0065] The acquisition unit 20 acquires, as the amount of occlusion, for example, the difference between the peaks of the self-voice signal for each frequency from the internal microphones of the left and right acoustic devices corresponding to microphone 201b when one of the left and right hearing aids 2 is replaced with a measurement acoustic device that is less sealed than the hearing aid 2.

[0066] The measurement acoustic device, which has a lower degree of sealing than the hearing aid 2, is an earpiece or housing that has been acoustically adjusted by opening a vent or other method to create conditions that are almost the same as when the acoustic device is not being worn in the frequency band where occlusion cancellation is effective.

[0067] The self-voice signal used to obtain the amount of occlusion is a signal of the user's voice that follows a guide to obtain the amount of occlusion, such as sounds such as "eh," "hmm," or "oh" emitted by the user for several seconds, or a signal of the user's voice when reading a sentence.

[0068] (Signal Processing Unit 21) In FIG. 4, the signal processing unit 21 includes a microphone amplifier 211, a hearing aid processing unit 212, an equalizing processing unit (adjustment unit) 213, a microphone amplifier 214, a subtraction unit 215, an occlusion cancellation unit 216, an addition unit 217, and a power amplifier 218.

[0069] (Microphone amplifier 211) The microphone amplifier 211 is an amplifier for adjusting the volume of the outside acoustic signal. The microphone amplifier 211 adjusts the volume of the outside acoustic signal acquired by the outside sound collection unit 20f, for example by amplifying the volume of the outside acoustic signal. The microphone amplifier 211 then inputs the volume-adjusted outside acoustic signal to the hearing aid processing unit 212.

[0070] (Hearing aid processor 212) The hearing aid processor 212 performs the above-mentioned hearing aid processing. An example of the hearing aid processor 212 will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining an example of the hearing aid processor 212. In Fig. 5, the hearing aid processor 212 includes a feedback cancellation section 212A, a voice enhancement processing section 212B, and a hearing correction processing section 212C.

[0071] (Feedback Cancellation Unit 212A) The feedback cancellation unit 212A uses an output sound signal, which is a signal corresponding to the output sound, as a signal for suppressing feedback that occurs when the output sound is input from the output unit 22 to the acquisition unit 20.

[0072] When the feedback cancellation unit 212A includes a feedback cancellation filter, the feedback cancellation unit 212A subtracts the result of processing the output sound signal through the feedback cancellation filter from the acoustic signal output from the microphone amplifier 211, thereby suppressing feedback.

[0073] (Audio enhancement processing unit 212B) The audio enhancement processing unit 212B performs audio enhancement processing to enhance the audio signal that the user wants to hear from among the outside audio signals. For example, the audio enhancement processing unit 212B suppresses noise in the outside audio signal by performing equalization processing on the outside audio signal based on the feature amount of the outside audio signal from which the output audio signal has been subtracted.

[0074] An example of the voice enhancement processing by the voice enhancement processing unit 212B will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining an example of the voice enhancement processing. In Fig. 6, the voice enhancement processing unit 212B suppresses stationary noise as the voice enhancement processing. The voice enhancement processing unit 212B uses a value obtained by subtracting a moving average from the instantaneous value of the sound pressure level of the outside acoustic signal at a predetermined frequency as a feature, and dynamically determines a gain, which is the amount of amplification of the volume of the outside acoustic signal at the predetermined frequency, according to the feature.

[0075] (Auditory correction processing unit 212C) The auditory correction processing unit 212C adjusts the volume of the outside acoustic signal based on the user's auditory characteristics that have been measured in advance. For example, the auditory correction processing unit 212C sets the amplification amount of the volume of the outside acoustic signal so that the amplification amount varies for each frequency based on the user's auditory characteristics. Specifically, if the user has difficulty hearing low-frequency sounds, the auditory correction processing unit 212C increases the amplification amount of the volume of the low-frequency outside acoustic signal.

[0076] In the above embodiments, the amplified self-voice signal should be suppressed. However, the hearing correction processor 212C can also amplify the volume of the self-voice signal as long as it is within a range that does not cause discomfort to the user. For example, if the user has difficulty hearing low-frequency sounds corresponding to the frequency band of the self-voice signal, the hearing correction processor 212C amplifies the volume of the low-frequency sounds within a range that does not cause discomfort to the user.

[0077] An example of the hearing correction processing by the hearing correction processing unit 212C will be described with reference to Fig. 7 . Fig. 7 is a diagram for explaining an example of the hearing correction processing. The hearing correction processing unit 212C controls the volume so that the input level of an outside acoustic signal of a predetermined frequency input to the hearing correction processing unit 212C and the output level of an outside acoustic signal of a predetermined frequency output from the hearing correction processing unit 212C have a nonlinear relationship as shown in Fig. 7 . Note that this processing is performed for each frequency band. Furthermore, the input / output relationship as shown in Fig. 7 is set differently for each frequency depending on the hearing characteristics.

[0078] (Equalizing Processing Unit 213) Returning to the explanation of Fig. 4, the equalizing processing unit 213 adjusts the amplitude and phase of the acoustic signal output from the hearing aid processing unit 212 in accordance with the inner acoustic signal. For example, the equalizing processing unit 213 adjusts the amplitude and phase of the acoustic signal output from the hearing aid processing unit 212 so that the occlusion cancellation unit 216 does not suppress an outer-origin acoustic signal, which is a signal component attributable to the acoustic signal output from the receiver 222 of the output unit 22 and is included in the inner acoustic signal.

[0079] The equalizing processor 213 can also perform equalization processing according to the characteristics of the microphone 201b on the acoustic signal output from the hearing aid processor 212. For example, if the transfer function based on the characteristics of the microphone 201b and the microphone amplifier 214 is "M(i)", the equalizing processor 213 imparts a frequency characteristic of "target characteristic - M(i)" to the outside acoustic signal, the volume of which has been amplified at frequencies according to the hearing characteristics.

[0080] The amount of occlusion cancellation related to the processing and purpose of the equalizing processing unit 213 is performed by an occlusion processing adjustment unit (adjustment unit), which is an application installed in the control unit 46 of the information processing device 40 such as a smartphone.

[0081] The occlusion processing adjustment unit adjusts the amount of occlusion cancellation, which is the amount by which occlusion is attenuated, based on the amount of adjustment of the volume of the outside acoustic signal by the hearing aid processing, before the operation of the acoustic processing.

[0082] For example, the occlusion processing adjustment unit performs various settings by adjusting various parameters such as the filter gain described below based on setting information received from the information processing device 40 via a UI of an application or the like of the information processing device 40, such as a smartphone.

[0083] The occlusion processing adjustment unit sets a target value for each frequency based on the setting information. The occlusion processing adjustment unit also compares the amount of occlusion with the target value for each frequency. For example, if the amount of occlusion, which is the amount of peak amplification, is greater than the target value for the frequency corresponding to the peak frequency, the occlusion processing adjustment unit sets the target value as the amount of occlusion cancellation. If the amount of occlusion, which is the amount of peak amplification, is equal to or less than the target value for the frequency corresponding to the peak frequency, the occlusion processing adjustment unit changes the amount of occlusion cancellation for the specified frequency to 0.

[0084] The occlusion processing adjustment unit sets an occlusion cancellation filter, which is a filter for attenuating occlusion, according to a target value as follows: Specifically, the "occlusion cancellation filter" is a filter that outputs an occlusion cancellation signal, which is a signal that can suppress occlusion when an output sound output from the output unit 22 in response to an input of an inside acoustic signal is superimposed on the inside acoustic signal at the user's eardrum.

[0085] First, the occlusion processing adjustment unit searches for a filter "jmin" and a filter gain "αmin" that minimize the value of the following formula (1). Next, the occlusion processing adjustment unit selects a filter in which the coefficient of the filter "jmin" is multiplied by the filter gain "αmin" as the occlusion cancellation filter.

[0086]

[0087] In equation (1), "i" is a frequency. "j" is a filter. "D(i)" is a target value set for each frequency. "Ej(i)" is an adjusted expected cancellation amount obtained by multiplying the transfer function of "Ej(i)," which is the occlusion cancellation amount (expected cancellation amount) for each frequency expected for each of a plurality of pre-designed filters, by a filter gain "α," which is a scalar value between 0 and 1.

[0088] The setting of the occlusion cancellation filter by the occlusion processing adjustment unit described above will be described in detail with reference to Figs. 8 to 10. Fig. 8 is a graph showing the target value of the occlusion cancellation amount for each frequency. Fig. 9 is a graph showing the expected cancellation amount of a pre-designed filter for each frequency. Fig. 10 is a graph showing the target value of the occlusion cancellation amount for each frequency, the expected cancellation amount of a pre-designed filter, and the adjusted expected cancellation amount.

[0089] The occlusion processing adjustment unit brings the expected cancellation amount "Ej(i)" of the designed filter closer to the target value "D(i)" in Fig. 8. The occlusion processing adjustment unit sets the filter "jmin" as the occlusion cancellation filter, which has an adjusted expected cancellation amount "Ej(i, α)" that is closest to "D(i)" based on each of "Ej(i)" such as "E1(i)," "E2(i)," and "E3(i)" in Fig. 9. "Ej(i)" is determined by the following equation (2):

[0090]

[0091] "H(i)" in equation (2) is a transfer function based on the characteristics of the headphone driver for driving the output unit 22 such as headphones and the power amplifier 218 such as a headphone amplifier, and is a transfer function measured in a state where occlusion is suppressed. "F(i)" is a transfer function based on the characteristics from the headphone driver to the microphone 201b. "M(i)" is the same as described above.

[0092] "C(i)" is a transfer function based on the characteristics of the A / D conversion unit 202b and the D / A conversion unit 221. "β(i)" is a transfer function based on the characteristics of the filter of the FB noise cancellation unit 226, which is multiplied when the hearing aid 2 further includes the FB noise cancellation unit 226 described below.

[0093] "Ej(i, α)" is obtained by adjusting the transfer function of "Ej(i)" by multiplying it by a filter gain "α" as shown in the following equation (3). The occlusion processing adjustment unit varies "α" of "Ej(i, α)" corresponding to each filter within a scalar value range of 0 to 1. The occlusion processing adjustment unit sets the filter corresponding to "Ej(i, α)" that is closest to "D(i)" as the occlusion cancellation filter.

[0094] 10, the shape of "Ej(i)" is close to "D(i)" for both "E1(i)" and "E3(i)." However, "Ej(i)" is expressed as the maximum expected amount of cancellation for each frequency of filter "j," and when multiplied by the transfer function of "α," which is between 0 and 1, "Ej(i,α)" does not have a larger amount of cancellation than "Ej(i)."

[0095] Therefore, "E1(i, α)" based on "E1(i)" having a larger amount of cancellation than "D(i)" is closest to "D(i)", rather than "E3(i)" having a smaller amount of cancellation than "D(i)". For this reason, the occlusion processing adjustment unit sets the filter of "1" corresponding to "E1(i, α)" as the occlusion cancellation filter.

[0096]

[0097] Note that "α" itself does not depend on frequency, but "Ej(i, α)" varies depending on frequency. Making "α" itself dependent on frequency is equivalent to designing a new filter. Designing a new filter is not impossible. However, there is no straightforward method for ensuring the stability of a newly designed filter. For this reason, it is difficult to make "α" itself dependent on frequency.

[0098] In the above example, the occlusion processing adjustment unit cannot set the target value to a value equal to or greater than "Ej(i)," which is expressed as the maximum expected cancellation amount for each frequency. However, the occlusion processing adjustment unit can set the target value to a value equal to or greater than "Ej(i)" by adjusting the value of parameters such as "α."

[0099] (Microphone amplifier 214) Returning to the description of Fig. 4, the microphone amplifier 214 is an amplifier for adjusting the volume of the inside acoustic signal. The microphone amplifier 214 adjusts the volume, for example by amplifying the volume of the inside acoustic signal acquired by the inside sound collection unit 20b. Next, the microphone amplifier 214 inputs the acoustic signal output from the microphone amplifier 214 to the subtraction unit 215.

[0100] (Subtraction Unit 215) The subtraction unit 215 subtracts the acoustic signal output from the hearing aid processing unit 212 from the inner acoustic signal.

[0101] (Occlusion Cancellation Unit 216) The occlusion cancellation unit 216 generates an occlusion cancellation signal based on the acoustic signal output from the subtraction unit 215. The occlusion cancellation signal is a signal that can suppress a signal component corresponding to the input signal to the occlusion cancellation unit 216 when the output sound output from the output unit 22 is superimposed on an inner acoustic signal at the eardrum of the user.

[0102] (Adder 217) The adder 217 adds the acoustic signal output from the hearing aid processor 212 and the signal output from the occlusion cancellation unit 216 that can suppress occlusion at the eardrum.

[0103] (Power amplifier 218) The power amplifier 218 is an amplifier for adjusting the volume of the acoustic signal output from the adder 217. The power amplifier 218 adjusts the volume, for example by amplifying the volume of the acoustic signal output from the adder 217. Subsequently, the power amplifier 218 inputs the acoustic signal output from the power amplifier 218 to the output unit 22.

[0104] (Output unit 22) The output unit 22 outputs to the user an output sound in which the volume of the outside acoustic signal and the amount of occlusion cancellation have been adjusted by the hearing aid processing unit 212 and the occlusion processing adjustment unit. In Fig. 4, the output unit 22 outputs the output sound of the acoustic signal output from the power amplifier 218.

[0105] 3.2 Acoustic Processing Method Next, the acoustic processing method according to the first embodiment will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a flowchart of the adjustment of acoustic processing according to the first embodiment. Fig. 12 is a flowchart of the operation of acoustic processing according to the first embodiment.

[0106] (Adjustment of Acoustic Processing) First, with reference to Fig. 11, a method for adjusting acoustic processing that is performed before performing an operation as acoustic processing will be described. In step S11, the acquisition unit 20 acquires the user's auditory characteristics. In step S12, the occlusion cancellation unit 216 sets a target value for occlusion based on the auditory characteristics. In step S13, the acquisition unit 20 acquires the auditory characteristics that have been adjusted based on counseling by an audiologist, etc. In step S14, the acquisition unit 20 acquires the amount of occlusion.

[0107] In step S15, the occlusion processing adjustment unit compares the amount of occlusion with a target value. In step S16, the occlusion processing adjustment unit adjusts the amount of occlusion cancellation. In step S17, the occlusion processing adjustment unit sets an occlusion cancellation filter according to the target value.

[0108] (Acoustic Processing Operation) The operating method of the acoustic processing will be described with reference to Fig. 12. In step S21, the acquisition unit 20 acquires an outer acoustic signal and an inner acoustic signal. In step S22, the feedback cancellation unit 212A suppresses feedback. In step S23, the audio enhancement processing unit 212B enhances the acoustic signal that the user wants to hear from the outer acoustic signal.

[0109] In step S24, the hearing correction processing unit 212C adjusts the volume of the outside acoustic signal based on the user's hearing characteristics measured in advance. In step S25, the occlusion cancellation unit 216 generates an occlusion cancellation signal. In step S26, the output unit 22 outputs to the user the output sound in which the volume of the outside acoustic signal and the amount of occlusion cancellation have been adjusted by the hearing aid processing unit 212 and the occlusion processing adjustment unit.

[0110] 4 and may include, for example, only the acquisition unit 20, the hearing correction processing unit 212C, the equalizing processing unit 213, the occlusion cancellation unit 216, and the output unit 22. The equalizing processing unit 213 may also function as, for example, the occlusion processing adjustment unit described above.

[0111] (Second Modification) When the user also listens to calls and music at the same time, the hearing aid 2 can be configured as shown in Fig. 13. Fig. 13 is a block diagram of a hearing aid 2a according to a second modification of the first embodiment.

[0112] 13 , the signal processing unit 21a of the hearing aid 2a further includes an adder 219 in addition to the signal processing unit 21. The adder 219 adds the acoustic signal output from the hearing aid processing unit 212 to an acoustic signal such as a call sound or music input from the outside. The adder 219 inputs the signal output from the adder 219 to the equalizing processing unit 213 and the adder 217.

[0113] (Third Modification) As a variation of the hearing aid 2, the hearing aid 2 can be configured as shown in Fig. 14. Fig. 14 is a block diagram of a hearing aid 2b according to a third modification of the first embodiment.

[0114] The signal processing unit 21 b of the hearing aid 2 b includes an equalizing processing unit 213 b with a different function from the equalizing processing unit 213 .

[0115] The equalizing processing unit 213b adjusts the amplitude of the acoustic signal output from the hearing aid processing unit 212 in accordance with the inner acoustic signal, similar to the equalizing processing unit 213. However, the equalizing processing unit 213b amplifies the volume of the outer acoustic signal corresponding to the amount of suppression of the volume of the outer-origin acoustic signal that is suppressed in conjunction with occlusion cancellation by the occlusion cancellation unit 216.

[0116] The hearing aid 2b may further include an equalizing processing unit 213, similar to the hearing aid 2. In this case, the equalizing processing unit 213 prevents the occlusion cancellation unit 216 from impairing the sound quality of the outside-originating sound signal by preventing suppression of the outside-originating sound signal included in the inside-originating sound signal.

[0117] Even if the volume of the outside-originated sound signal is suppressed as described above, the equalizing processing unit 213b can adjust the volume after suppression so that it is equivalent to the volume that would originally reach the user's eardrum.

[0118] Like the hearing aid 2a, the hearing aid 2b can further include an adder 219. In this case, the equalizing processing unit 213b performs equalization processing on the signal obtained by adding the acoustic signal output from the hearing aid processing unit 212 and the acoustic signal of the call sound, music, or the like by the adder 219.

[0119] <<4. Second embodiment>> <4.1 Hearing aid 2c> The hearing aid 2a can also suppress noise in external acoustic signals. Therefore, a hearing aid 2c according to the second embodiment will be described with reference to Fig. 15. Fig. 15 is a block diagram of the hearing aid 2c according to the second embodiment.

[0120] The signal processing unit 21c of the hearing aid 2c further includes an FF (Feed Forward) noise canceling unit (noise suppressing unit) 220 compared to the hearing aid 2a.

[0121] (FF noise cancellation unit 220) The FF noise cancellation unit 220 generates an acoustic signal for suppressing the acoustic signal of the environmental sound around the user that has leaked into the hearing aid 2 c. For example, if the FF noise cancellation unit 220 has a filter with a coefficient "x" that satisfies the following equation (4), it performs filtering to input the outside acoustic signal to the filter, thereby generating an acoustic signal for suppressing the acoustic signal of the environmental sound around the user that has leaked into the hearing aid 2 c.

[0122]

[0123] "F"(i)" in equation (4) is a transfer function based on the characteristics from the headphone driver to the microphone 201a of the outer sound collection unit 20a. H(i) is the same as described above. "M'(i)" is a transfer function based on the characteristics of the microphone 201f of the outer sound collection unit 20f and the microphone amplifier 211. "N(i)" is the outer acoustic signal. "F'(i)" is the transfer function of the propagation environment for the outer acoustic signal to reach the inside of the user's ear canal via the housing of the hearing aid 2c.

[0124] 4.2 Modification The hearing aid 2c can also suppress feedback that occurs in the path of the FF noise cancellation section 220. A hearing aid 2d according to a modification of the second embodiment will now be described with reference to Fig. 16. Fig. 16 is a block diagram of the hearing aid 2d according to a modification of the second embodiment.

[0125] The signal processing unit 21d of the hearing aid 2d is provided with a howling cancellation filter 223 having additional functions to the howling cancellation filter of the howling cancellation unit 212A, and a subtraction unit 224, in comparison with the signal processing unit 21c of the hearing aid 2c.

[0126] (Feedback Cancellation Filter 223) The feedback cancellation filter 223 adjusts to the delay caused by the hearing aid processing by the hearing aid processing unit 212, and then suppresses feedback occurring in the FF noise cancellation unit 220 based on the output sound signal.

[0127] The relationship between the howling cancellation filter of the howling cancellation unit 212A and the howling cancellation filter 223 will be described with reference to Fig. 17. Fig. 17 is a diagram for explaining an example of the howling cancellation filter of the howling cancellation unit 212A.

[0128] In FIG. 17, the howling cancellation filter 223, which is an example of the howling cancellation filter of the howling cancellation unit 212A, is composed of a cascade connection of a delay filter 2231 for increasing the delay to match the delay caused by the hearing aid processing, which is a process that involves algorithm delay, and a howling cancellation filter 2232 for the noise cancellation path.

[0129] For example, it is assumed that it takes 10 microseconds for the feedback cancellation filter 223 to receive an output sound from the output unit 22, such as a speaker, after an acoustic signal is input to the microphone 201f. In contrast, it is assumed that it takes 10 milliseconds for the path of the hearing aid processing unit 212 to receive an output sound from the output unit 22 after an acoustic signal is input to the microphone 201f. In this case, the delay filter 2231 delays the processing by the noise cancellation path feedback cancellation filter 2232 by 9.99 milliseconds, which is 10 milliseconds minus 10 microseconds.

[0130] (Subtraction unit 224) Returning to the description of Fig. 16 , the subtraction unit 224 subtracts the output signal from the feedback cancellation filter 223 from the outside acoustic signal (the input signal to the outer microphone 201f). This corresponds to estimating and subtracting from the outside acoustic signal a signal component resulting from the output sound output from the output unit 22, such as a speaker, leaking into the outer microphone 201f. The subtraction unit 224 also inputs the acoustic signal output from the subtraction unit 224 to the FF noise cancellation unit 220.

[0131] <<5. Third embodiment>> The hearing aid 2 can separate an inner acoustic signal into an outer-originated acoustic signal and an inner-originated acoustic signal. A hearing aid 2e according to a third embodiment will now be described with reference to Fig. 18. Fig. 18 is a block diagram of the hearing aid 2e according to the third embodiment.

[0132] Compared to the signal processing unit 21, the signal processing unit 21e of the hearing aid 2e further comprises a separation unit 225 and an FB (Feedback) noise cancellation unit (external noise suppression unit) 226. The signal processing unit 21e also comprises an occlusion cancellation unit 216e with a different function from the occlusion cancellation unit 216.

[0133] (Separation unit 225) The separation unit 225 separates the inner acoustic signal into an outer-origin acoustic signal and an inner-origin acoustic signal based on the outer acoustic signal. For example, if the separation unit 225 includes a separation filter for performing this separation, the separation unit 225 separates the inner acoustic signal into the outer-origin acoustic signal and the inner-origin acoustic signal by performing a filter process of inputting the inner acoustic signal to the separation filter.

[0134] An example of the separation unit 225 will be described with reference to Fig. 19. Fig. 19 is a diagram illustrating an example of the separation unit 225. In Fig. 19, the separation unit 225 includes a separation filter 2251 and a subtraction unit 2252.

[0135] The separation filter 2251 outputs an outside-originated acoustic signal in response to an input of the outside acoustic signal. For example, the separation filter 2251 outputs the outside-originated acoustic signal by adjusting the amplitude and phase in response to the inside acoustic signal. The subtraction unit 2252 generates an inside-originated acoustic signal by subtracting the outside-originated acoustic signal from the acoustic signal output from the subtraction unit 215.

[0136] The separation unit 225 may use a separation filter 2251 with predetermined coefficients determined by measurements at the time of design, or may use a separation filter 2251 with adaptively determined coefficients. When the separation unit 225 uses a separation filter 2251 with adaptively determined coefficients, the separation filter 2251 is updated based on the probability that an own voice signal is detected from an inner acoustic signal.

[0137] Specifically, the separation unit 225 determines that a self-voice signal has been detected if the difference in short-time energy between the inner acoustic signal and the outer acoustic signal is equal to or greater than a predetermined value. The separation unit 225 can also determine that a self-voice signal has been detected if a value output from a function that outputs a value between 0 and 1 inclusive in response to an input of the short-time energy difference is equal to or greater than a predetermined value.

[0138] The short-term energy is the acoustic energy per short period of time. A "short period" corresponds to a "short period" defined in, for example, spectrum analysis, which analyzes the frequency of an acoustic signal in a short period of time extracted from the acoustic signal. When the acoustic processing device is an earphone, a headphone, or the like, the "short period" is, for example, several tens of milliseconds. When the acoustic processing device is a hearing aid 2, the frequency of the acoustic signal may be analyzed in a shorter time than with earphones or headphones, so the "short period" is, for example, several milliseconds or more and several tens of milliseconds or less.

[0139] The separation unit 225 updates the separation filter 2251 only when the own voice signal is not detected from the inner acoustic signal, or decreases the amount of update of the separation filter 2251 as the probability of detecting the own voice signal increases.

[0140] When updating separation filter 2251, separation unit 225 updates the coefficients of separation filter 2251 so as to minimize the mean square of the difference between the time signals, which are the differences between the inner acoustic signal and the outer acoustic signal per short time, for example. Furthermore, when the amount of update of separation filter 2251 is reduced the higher the probability that a self-voice signal is detected, separation unit 225 multiplies the update term of separation filter 2251 by another coefficient instead of updating the coefficients of separation filter 2251 so as to minimize the mean square of the difference between the time signals.

[0141] Specifically, when the coefficient of separation filter 2251 is "A(n)," separation unit 225 normally updates the coefficient to "A(n)+d(n)" by minimizing the root mean square of the difference between time signals, but in this case separation unit 225 updates the coefficient to "A(n)+0.1*d(n)." In this way, by multiplying "d(n)," which is the update term for the coefficient, by another coefficient of 0.1, separation unit 225 can update the coefficient at one-tenth the normal speed.

[0142] The above-described method of updating the separation filter 2251 by the separation unit 225 follows the LMS (Least-Mean-Square) algorithm. Since the LMS is a method commonly used in this field, as shown in the following reference, a detailed description will be omitted. Reference: S. Haykin (2002). Adaptive Filter Theory, 4th Edition, Prentice-Hall.

[0143] (FB noise cancellation unit 226) Returning to the description of Fig. 18 , the FB noise cancellation unit 226 generates an acoustic signal for suppressing the acoustic signal of environmental sound around the user that has leaked into the hearing aid 2e, based on the externally-originated acoustic signal. For example, the FB noise cancellation unit 226 performs filtering to input the externally-originated acoustic signal output from the separation unit 225 into a filter with coefficients determined in the same way as the FF noise cancellation unit 220, thereby generating an acoustic signal for suppressing the acoustic signal of environmental sound around the user that has leaked into the hearing aid 2e.

[0144] (Occlusion Cancellation Unit 216e) The occlusion cancellation unit 216e generates an occlusion cancellation signal based on the inside-originated sound signal. For example, the occlusion cancellation unit 216e generates an occlusion cancellation signal based on the inside-originated sound signal, similar to the occlusion cancellation unit 216.

[0145] <<6. Fourth embodiment>> <6.1 Hearing aid 2f> The hearing aid 2 can also perform own voice signal suppression processing, which suppresses the own voice signal from the outside acoustic signal based on the inside acoustic signal. Therefore, a hearing aid 2f according to the fourth embodiment will be described with reference to Fig. 20. Fig. 20 is a block diagram of the hearing aid 2f according to the fourth embodiment.

[0146] The hearing aid processor 212f of the signal processor 21f of the hearing aid 2f suppresses the own voice signal from the outside acoustic signal based on the inside acoustic signal. In Fig. 20, the hearing aid processor 212f uses the acoustic signal output from the subtractor 215 as a signal for suppressing the own voice signal.

[0147] An example of the hearing aid processor 212f will be described with reference to Fig. 21. Fig. 21 is a diagram for explaining an example of the hearing aid processor 212f. In Fig. 21, the hearing aid processor 212f further includes an own voice signal canceller 212D in addition to the hearing aid processor 212.

[0148] (Own voice signal canceling unit 212D) The own voice signal canceling unit 212D includes an own voice signal canceling filter 2121D and a subtraction unit 2122D.

[0149] The own voice signal cancellation filter 2121D outputs an own voice similar signal, which is an audio signal whose difference in volume for each frequency from the own voice signal is within a predetermined range, in response to input of the audio signal output from the subtraction unit 215. The subtraction unit 2122fD subtracts the own voice similar signal from the outside audio signal.

[0150] The own voice signal cancellation section 212D may use an own voice signal cancellation filter 2121D with predetermined coefficients determined by measurement during design, or may use an own voice signal cancellation filter 2121D with adaptively determined coefficients. When the own voice signal cancellation section 212D uses an own voice signal cancellation filter 2121D with adaptively determined coefficients, the own voice signal cancellation section 212D updates the own voice signal cancellation filter 2121D in the same way as the separation filter 2251.

[0151] The self-voice signal cancellation unit 212D can adjust the amount of self-voice signal suppression that suppresses the self-voice signal from the external acoustic signal by multiplying the coefficient of the self-voice signal cancellation filter 2121D by another coefficient. The amount of self-voice signal suppression can take any value equal to or greater than 0 dB, as long as it is an amount that the user finds comfortable.

[0152] 6.2 Acoustic Processing Method Next, an acoustic processing method according to the fourth embodiment will be described with reference to Fig. 22 and Fig. 23. Fig. 22 is a flowchart of adjustment of acoustic processing according to the fourth embodiment. Fig. 23 is a flowchart of operation of acoustic processing according to the fourth embodiment.

[0153] (Adjustment of Acoustic Processing) A method of adjusting acoustic processing according to the fourth embodiment will be described with reference to Fig. 22. In step S17, the own voice signal canceller 212D adjusts the amount of suppression of the own voice signal.

[0154] (Acoustic Processing Operation) The operating method of the acoustic processing according to the fourth embodiment will be described with reference to Fig. 23. In step S27, the own voice signal canceller 212D suppresses the own voice signal from the outside acoustic signal based on the inside acoustic signal.

[0155] 6.3 Modifications As a variation of the own voice signal suppression processing, the hearing aid processor 212f of the hearing aid 2f can also change the amount of own voice signal suppression based on whether or not the own voice signal is detected from the inside acoustic signal. Therefore, a hearing aid 2g according to a modification of the fourth embodiment will be described with reference to Fig. 24. Fig. 24 is a block diagram of a hearing aid 2g according to a modification of the fourth embodiment.

[0156] The hearing aid processor 212g of the signal processor 21g of the hearing aid 2g changes the amount of suppression of the own voice signal based on whether or not the own voice signal is detected from the inside acoustic signal.

[0157] An example of the hearing aid processor 212g will be described with reference to Fig. 25. Fig. 25 is a diagram for explaining an example of the hearing aid processor 212g. In Fig. 25, the hearing aid processor 212g further includes an own voice signal suppressor 212E instead of the own voice signal canceller 212D.

[0158] (Own voice signal suppression unit 212E) The own voice signal suppression unit 212E includes a detection unit 2121E and an equalizing processing unit 2122E. The detection unit 2121E detects the own voice from the inner acoustic signal. The equalizing processing unit 2122E changes the amount of suppression of the own voice signal based on whether the own voice signal is detected from the inner acoustic signal. For example, the equalizing processing unit 2122E changes the amount of suppression of the own voice signal so that the higher the probability that the own voice signal is detected from the inner acoustic signal, the greater the amount of suppression of the own voice signal.

[0159] Specifically, the equalizing processing unit 2122E suppresses the self-voice signal from the outer acoustic signal by calculating the product for each frequency of the probability that the self-voice signal is detected from the inner acoustic signal, a preset coefficient between 0 and 1, and the maximum suppression amount of the self-voice signal, as the actual suppression amount of the self-voice signal.

[0160] The relationship between frequency and the amount of suppression of the own voice signal can be represented graphically as shown in Figure 26. Figure 26 is a graph showing the relationship between frequency and the amount of suppression of the own voice signal. In Figure 26, the equalizing processing unit 2122E changes the actual amount of suppression so that the amount of suppression of the own voice signal in the low frequency range corresponding to the frequency band of the own voice signal is increased, and also changes the actual amount of suppression in accordance with the probability that the own voice signal is detected and a preset coefficient.

[0161] Furthermore, instead of the probability that an own voice signal is detected from the inner acoustic signal, the equalizing processing unit 2122E can also use the product of 1 when an own voice signal is detected from the inner acoustic signal and 0 when an own voice signal is not detected as the actual suppression amount of the own voice signal.

[0162] The hearing aid processor 212g may further include an own voice signal cancellation unit 212D. For example, if the amount of occlusion cancellation is equal to or greater than a predetermined value, the own voice signal cancellation unit 212D suppresses the own voice signal. This allows the hearing aid processor 212g to prevent deterioration of the sound quality of the outside acoustic signal compared to when the own voice signal is suppressed by the own voice signal suppression unit 212E.

[0163] Furthermore, if the amount of occlusion cancellation is smaller than a predetermined value, the own voice signal suppressor 212E suppresses the own voice signal. This allows the hearing aid processor 212g to suppress the own voice signal by a greater amount than when the own voice signal is suppressed by the own voice signal canceller 212D.

[0164] <<7. Other Embodiments>> The processes according to the embodiments can be implemented in various different forms other than the above-described embodiments.

[0165] Of the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using known methods. In addition, the information including the processing procedures, specific names, various data, and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified. The various information shown in each drawing is not limited to the information shown in the drawings.

[0166] The components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads and usage conditions.

[0167] The above-described embodiments and modifications can be combined as appropriate within the scope of not causing any contradiction in the processing content.

[0168] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0169] <<8. Effects of the Sound Processing Device According to the Present Disclosure>> As described above, the sound processing device according to the present disclosure (hearing aid 2 in this embodiment) includes an acquisition unit (acquisition unit 20 in this embodiment), a hearing aid processing unit (hearing aid processing unit 212 in this embodiment), an adjustment unit (occlusion processing adjustment unit in this embodiment), and an output unit (output unit 22 in this embodiment).

[0170] The acquisition unit acquires an outer acoustic signal, which is a signal derived from sound propagating outside the user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal. The hearing aid processing unit adjusts the volume of the outer acoustic signal based on the user's hearing characteristics measured in advance. The adjustment unit adjusts an occlusion cancellation amount, which is an amount by which occlusion caused by the volume of the inner acoustic signal being amplified when the acoustic device (in this embodiment, a hearing aid 2) is worn on the user's ear, based on the adjustment amount of the volume of the outer acoustic signal made by the hearing aid processing unit. The output unit outputs to the user an output sound in which the volume and amount of occlusion cancellation of the outer acoustic signal have been adjusted by the hearing aid processing unit and the adjustment unit.

[0171] In this way, the sound processing device according to the present disclosure adjusts the amount of occlusion cancellation based on the amount of adjustment of the volume of the outside sound signal by the hearing aid processing. As a result, the sound processing device can suppress sounds such as the user's own voice that are overly amplified in the user's ear and that the user does not want to hear, while allowing the user to hear sounds that have been amplified to a level that the user finds difficult to hear. This reduces the user's discomfort and makes the sounds that the user finds difficult to hear easier to hear.

[0172] The adjustment unit adjusts the amount of occlusion cancellation further based on the amount of occlusion, which is the amount of amplification of the volume of the inner acoustic signal amplified by wearing the acoustic device on the user's ear, measured in advance. This allows the sound processing device to adjust the amount of occlusion cancellation so that occlusion cancellation is performed only when the effect of occlusion is stronger than the hearing aid processing, such as when the amount of occlusion is greater than the amount of amplification of the volume of the outer acoustic signal.

[0173] The sound processing device further includes a howling cancellation unit (in this embodiment, a howling cancellation unit 212A) that uses an output sound signal, which is a signal corresponding to the output sound, as a signal for suppressing howling that occurs when the output sound is input from the output unit to the acquisition unit.This allows the sound processing device to suppress howling even if it occurs due to hearing aid processing.

[0174] The adjustment unit further includes a subtraction unit (in this embodiment, subtraction unit 215) that adjusts the amplitude and phase of the acoustic signal output from the hearing aid processing unit in accordance with the inner acoustic signal and subtracts the acoustic signal output from the adjustment unit from the inner acoustic signal, and an occlusion cancellation unit (in this embodiment, occlusion cancellation unit 216) that generates, based on the acoustic signal output from the subtraction unit, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to the input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner acoustic signal at the user's eardrum.

[0175] As a result, even when the sound processing device performs occlusion cancellation, it does not excessively suppress the outside-originated sound signal included in the inside sound signal, and therefore can appropriately suppress occlusion without impairing the sound quality, etc., of the outside-originated sound signal.

[0176] The sound processing device further includes an adder (adder 217 in this embodiment) that adds the sound signal output from the hearing aid processor and the sound signal output from the subtractor, thereby enabling the sound processing device to output to the user an output sound in which occlusion has been suppressed, based on the sound signal output from the adder, without impairing the sound quality, etc., of the outside-originated sound signal.

[0177] The adjustment unit (in this embodiment, the equalizing processing unit 213b) adjusts the amplitude of the acoustic signal output from the hearing aid processing unit in accordance with the inner acoustic signal, and further includes an occlusion cancellation unit that generates, based on the inner acoustic signal, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to the input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner acoustic signal at the user's eardrum, and an adder that adds the acoustic signal output from the adjustment unit and the acoustic signal output from the occlusion cancellation unit.

[0178] This allows the sound processing device to amplify the amplitude of the outside sound signal before the outside-originated sound signal is suppressed due to occlusion cancellation, so that even if the volume of the outside-originated sound signal is suppressed, the sound processing device can adjust the volume after the suppression to be equivalent to the volume that would originally reach the user's eardrum.

[0179] The adjustment unit sets a target value for occlusion, and if the amount of occlusion is greater than the target value, sets the target value as the amount of occlusion cancellation, thereby enabling the sound processing device to adjust the amount of occlusion cancellation so that occlusion cancellation is performed only when the sound processing device is strongly affected by occlusion.

[0180] The adjustment unit sets an occlusion cancellation filter corresponding to a target value as an occlusion cancellation filter that is a filter for attenuating occlusion.

[0181] This allows the sound processing device to set, as the occlusion cancellation filter, a filter that can cancel occlusion up to a value closest to the target value from among a plurality of pre-designed filters, thereby enabling appropriate occlusion cancellation.

[0182] When the amount of occlusion, which is the amplification amount of the peak corresponding to the peak in the acoustic spectrum of the user's own voice signal, which is the signal of the user's own voice amplified by wearing the acoustic device, is greater than the target value for the frequency corresponding to the frequency of the peak, the adjustment unit sets the target value as the amount of occlusion cancellation. This allows the acoustic processing device to compare the amount of occlusion with the target value for each frequency, thereby more appropriately adjusting the amount of occlusion cancellation.

[0183] The sound processing device further includes a noise cancellation unit (in this embodiment, an FF noise cancellation unit 220) that generates, based on the output sound signal, a sound signal for suppressing the sound signal of the environmental sound around the user that has leaked into the sound device. This allows the sound processing device to appropriately suppress noise included in the outside sound signal from which the output sound signal has been subtracted, thereby improving the ease with which the user can hear the sound.

[0184] The howling cancellation unit includes a howling cancellation filter that suppresses howling that occurs in the noise cancellation unit based on the output sound signal after adjusting for a delay caused by the hearing aid processing by the hearing aid processing unit. This allows the sound processing device to suppress howling after adjusting for a delay caused by the hearing aid processing, thereby preventing a loss of noise suppression performance based on the output sound signal used to suppress howling.

[0185] The sound processing device further includes a separation unit (separation unit 225 in this embodiment) that separates the inner sound signal based on the outer sound signal into an outer-originating sound signal, which is an outer-originating sound signal among the inner sound signals, and an inner-originating sound signal, which is an inner-originating sound signal among the inner sound signals, and the occlusion cancellation unit generates an occlusion cancellation signal based on the inner-originating sound signal.

[0186] This allows the sound processing device to appropriately suppress the amount of occlusion from the inside-originated sound signal without suppressing the outside-originated sound signal, thereby improving the ease with which the user can hear the sound.

[0187] The separation unit updates the separation filter for separation based on the probability that an own voice signal, which is a signal of the user's own voice, will be detected from the inner acoustic signal. When the own voice signal is detected, the sound processing device updates the separation filter to enable appropriate separation into two signals.

[0188] The separation unit updates the separation filter only when the own voice signal is not detected from the inner acoustic signal, or reduces the amount of update of the separation filter as the probability of detecting the own voice signal increases. The sound processing device can more appropriately separate the two signals by setting the update conditions of the separation filter in detail.

[0189] The sound processing device further includes an outside-originating noise cancellation unit (in this embodiment, an FB noise cancellation unit 226) that generates an audio signal for suppressing the audio signal of the user's surrounding environmental sound that has leaked into the sound device, based on the outside-originating audio signal. This allows the sound processing device to suppress noise in the outside-originating audio signal even if it cannot sufficiently suppress occlusion, thereby improving the ease with which the user can hear the audio.

[0190] The hearing aid processor suppresses the user's own voice signal, which is a signal of the user's own voice, from the outer sound signal based on the inner sound signal. This allows the sound processing device to suppress the user's own voice signal, which causes occlusion, even if it cannot sufficiently suppress occlusion from the inner sound signal, thereby improving the ease with which the user can hear sounds.

[0191] The hearing aid processor varies the amount of suppression of the own voice signal based on whether or not the own voice signal is detected from the inner acoustic signal. This allows the sound processing device to increase the amount of suppression of the own voice signal when the own voice signal is detected, thereby further improving the ease with which the user can hear sounds.

[0192] The hearing aid processor changes the amount of suppression of the own voice signal so that the larger the probability that the own voice signal is detected from the inside sound signal, the larger the own voice signal becomes. This allows the sound processing device to increase the amount of suppression of the own voice signal the larger the probability that the own voice signal is detected, further improving the ease with which the user can hear sounds.

[0193] <<9. Hardware Configuration>> Information devices such as the hearing aid 2 according to each of the above-described embodiments are realized by a computer 1000 configured as shown in Fig. 27. Fig. 27 is a hardware configuration diagram showing an example of a computer that realizes the functions of the hearing aid 2 according to the embodiments. The computer 1000 comprises a CPU 1100, RAM 1200, ROM 1300, a HDD (Hard Disk Drive) 1400, a communication interface 1500, and an input / output interface 1600. The various components of the computer 1000 are connected by a bus 1050.

[0194] The CPU 1100 operates and controls each unit based on programs stored in the ROM 1300 or the HDD 1400. The CPU 1100 loads the programs stored in the ROM 1300 or the HDD 1400 into the RAM 1200 and executes processing corresponding to the various programs.

[0195] The ROM 1300 stores boot programs such as a Basic Input Output System (BIOS) that is executed by the CPU 1100 when the computer 1000 starts up, and programs that depend on the hardware of the computer 1000 .

[0196] HDD 1400 is a computer-readable recording medium that non-temporarily records programs executed by CPU 1100 and data used by such programs. Specifically, HDD 1400 is a recording medium that records the acoustic processing program according to the present disclosure, which is an example of program data 1450.

[0197] The communication interface 1500 is an interface for connecting the computer 1000 to an external network 1550 (such as the Internet). The CPU 1100 receives data from other devices and transmits data generated by the CPU 1100 to other devices via the communication interface 1500.

[0198] The input / output interface 1600 is an interface for connecting the input / output device 1650 and the computer 1000. The CPU 1100 receives data from input devices such as a keyboard and a mouse via the input / output interface 1600. The CPU 1100 transmits data to output devices such as a display, a speaker, and a printer via the input / output interface 1600. The input / output interface 1600 can also function as a media interface for reading a program recorded on a predetermined recording medium.

[0199] The media may be optical recording media such as DVDs (Digital Versatile Discs) and PDs (Phase Change Rewritable Discs), magneto-optical recording media such as MOs (Magneto-Optical disks), tape media, magnetic recording media, or semiconductor memories.

[0200] When the computer 1000 functions as the hearing aid 2 according to the embodiment, the CPU 1100 of the computer 1000 executes an information processing program loaded onto the RAM 1200 to realize the functions of the control unit 130. The information processing program according to the present disclosure and data in the storage unit 120 are stored in the HDD 1400.

[0201] The CPU 1100 reads and executes the program data 1450 from the HDD 1400. However, as another example, the CPU 1100 can also obtain these programs from other devices via an external network 1550.

[0202] <<10. Supplementary Information>> The present technology can also be configured as follows: (1) A sound processing device comprising: an acquisition unit that acquires an outer acoustic signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid processing unit that adjusts a volume of the outer acoustic signal based on pre-measured hearing characteristics of the user; an adjustment unit that adjusts an occlusion cancellation amount, which is an amount by which occlusion caused by amplification of the volume of the inner acoustic signal when the sound device is worn on the user's ear, based on an adjustment amount of the volume of the outer acoustic signal by the hearing aid processing unit; and an output unit that outputs to the user an output sound in which the volume of the outer acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit. (2) The sound processing device according to (1), wherein the adjustment unit adjusts the occlusion cancellation amount further based on a pre-measured amount of occlusion, which is an amplification amount of the volume of the inner acoustic signal amplified when the sound device is worn on the user's ear. (3) The sound processing device according to (1) or (2), further comprising: a howling cancellation unit that uses an output sound signal that is a signal corresponding to the output sound as a signal for suppressing howling that occurs when the output sound is input from the output unit to the acquisition unit. (4) The sound processing device according to any one of (1) to (3), wherein the adjustment unit adjusts the amplitude and phase of the sound signal output from the hearing aid processing unit according to the inner sound signal, and further comprises: a subtraction unit that subtracts the sound signal output from the adjustment unit from the inner sound signal; and an occlusion cancellation unit that generates, based on the sound signal output from the subtraction unit, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to the input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner sound signal at the eardrum of the user. (5) The sound processing device according to (4), further comprising an addition unit that adds the sound signal output from the hearing aid processing unit and the sound signal output from the subtraction unit.(6) The sound processing device according to any one of (1) to (3), wherein the adjustment unit adjusts the amplitude of the sound signal output from the hearing aid processing unit in accordance with the inner sound signal, an occlusion cancellation unit that generates, based on the inner sound signal, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to an input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner sound signal at the eardrum of the user, and an adder that adds the sound signal output from the adjustment unit and the sound signal output from the occlusion cancellation unit. (7) The sound processing device according to (2), wherein the adjustment unit sets a target value for the amount of occlusion cancellation, and, if the amount of occlusion is greater than the target value, sets the target value to the amount of occlusion cancellation. (8) The sound processing device according to (7), wherein the adjustment unit sets an occlusion cancellation filter corresponding to the target value as an occlusion cancellation filter that outputs the occlusion cancellation signal in response to input of the inside acoustic signal. (9) The sound processing device according to (7) or (8), wherein the adjustment unit sets the target value as the occlusion cancellation amount when the amount of occlusion, which is the amplification amount of a peak corresponding to a crest in the acoustic spectrum of an own voice signal that is a signal of the user's own voice amplified by wearing the sound device, is greater than the target value for a frequency corresponding to the frequency of the peak. (10) The sound processing device according to (3), further comprising a noise cancellation unit that generates, based on the output sound signal, an acoustic signal for suppressing an acoustic signal of environmental sound around the user that has leaked into the sound device. (11) The sound processing device according to (10), wherein the feedback cancellation unit includes a howling cancellation filter that suppresses howling occurring in the noise cancellation unit based on the output sound signal after adjusting for a delay caused by hearing aid processing by the hearing aid processing unit.(12) The sound processing device according to (4), further comprising a separation unit that separates the inner acoustic signal based on the outer acoustic signal into an outer-origin acoustic signal that is an acoustic signal originating from the outer side of the inner acoustic signal and an inner-origin acoustic signal that is an acoustic signal originating from the inner side of the inner acoustic signal, wherein the occlusion cancellation unit generates the occlusion cancellation signal based on the inner-origin acoustic signal. (13) The sound processing device according to (12), wherein the separation unit updates a separation filter for performing the separation based on a probability that an own voice signal that is a signal of the user's own voice is detected from the inner acoustic signal. (14) The sound processing device according to (13), wherein the separation unit updates the separation filter only when the own voice signal is not detected from the inner acoustic signal, or reduces the amount of update of the separation filter as the probability of detection of the own voice signal increases. (15) The sound processing device according to any one of (12) to (14), further comprising an outside-originating noise cancellation unit that generates, based on the outside-originating sound signal, a sound signal for suppressing sound signals of environmental sounds around the user that have leaked into the sound device. (16) The sound processing device according to any one of (1) to (15), wherein the hearing aid processor suppresses an own voice signal, which is a signal of the user's own voice, from the outside sound signal based on the inside sound signal. (17) The sound processing device according to (16), wherein the hearing aid processor changes the amount of suppression of the own voice signal based on whether the own voice signal is detected from the inside sound signal. (18) The sound processing device according to (17), wherein the hearing aid processor changes the amount of suppression of the own voice signal so that the higher the probability that the own voice signal is detected from the inside sound signal, the greater the amount of suppression of the own voice signal.(19) An acoustic processing method executed by a computer, comprising: an acquisition process for acquiring an outer acoustic signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid process for adjusting a volume of the outer acoustic signal based on pre-measured hearing characteristics of the user; an adjustment process for adjusting an occlusion cancellation amount, which is an amount by which occlusion amplified in the volume of the inner acoustic signal when an acoustic device is worn on the user's ear, based on an adjustment amount of the volume of the outer acoustic signal by the hearing aid process; and an output process for outputting to the user an output sound in which the volume of the outer acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid process and the adjustment process. (20) A sound processing program for causing a computer to function as a sound processing device comprising: an acquisition unit that acquires an outer sound signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner sound signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid processing unit that adjusts the volume of the outer sound signal based on the user's hearing characteristics measured in advance; an adjustment unit that adjusts an occlusion cancellation amount, which is an amount by which occlusion caused by the volume of the inner sound signal being amplified when the sound device is worn on the user's ear, based on the adjustment amount of the volume of the outer sound signal by the hearing aid processing unit; and an output unit that outputs to the user an output sound in which the volume of the outer sound signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit.

[0203] 2 Hearing aid (acoustic device, sound processing device) 20 Acquisition unit 20f Outer sound collection unit 20b Inner sound collection unit 21 Signal processing unit 22 Output unit 211 Microphone amplifier 212 Hearing aid processing unit 212A Feedback cancellation unit 212B Speech enhancement processing unit 212C Hearing correction processing unit 213 Equalizing processing unit (adjustment unit) 214 Microphone amplifier 215 Subtraction unit 216 Occlusion cancellation unit 217 Addition unit 218 Power amplifier

Claims

1. A sound processing device comprising: an acquisition unit that acquires an outer sound signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner sound signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid processing unit that adjusts the volume of the outer sound signal based on the user's hearing characteristics measured in advance; an adjustment unit that adjusts an occlusion cancellation amount, which is the amount by which occlusion that is amplified when the sound device is worn on the user's ear, is attenuated, based on the amount of adjustment of the volume of the outer sound signal by the hearing aid processing unit; and an output unit that outputs to the user an output sound in which the volume of the outer sound signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit.

2. The sound processing device according to claim 1, wherein the adjustment unit adjusts the amount of occlusion cancellation further based on an amount of occlusion, which is a pre-measured amount of amplification of the volume of the inside sound signal amplified by wearing the sound device on the user's ear.

3. The sound processing device according to claim 1, further comprising a howling cancellation unit that uses an output sound signal that is a signal corresponding to the output sound as a signal for suppressing howling that occurs when the output sound is input from the output unit to the acquisition unit.

4. The sound processing device of claim 1, further comprising: a subtraction unit that adjusts the amplitude and phase of the sound signal output from the hearing aid processing unit in accordance with the inner sound signal, and subtracts the sound signal output from the adjustment unit from the inner sound signal; and an occlusion cancellation unit that generates, based on the sound signal output from the subtraction unit, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to the input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner sound signal at the eardrum of the user.

5. The sound processing device according to claim 4, further comprising an adder that adds the sound signal output from the hearing aid processor and the sound signal output from the subtractor.

6. The sound processing device according to claim 1, further comprising: an adjustment unit that adjusts the amplitude of the sound signal output from the hearing aid processing unit in accordance with the inner sound signal; an occlusion cancellation unit that generates, based on the inner sound signal, an occlusion cancellation signal that is a signal that can suppress a signal component corresponding to an input signal to the occlusion cancellation unit when the output sound output from the output unit is superimposed on the inner sound signal at the eardrum of the user; and an addition unit that adds the sound signal output from the adjustment unit and the sound signal output from the occlusion cancellation unit.

7. The sound processing device according to claim 2, wherein the adjustment unit sets a target value for the amount of occlusion cancellation, and when the amount of occlusion is greater than the target value, sets the target value as the amount of occlusion cancellation.

8. The sound processing device according to claim 7, wherein the adjustment unit sets an occlusion cancellation filter corresponding to the target value as an occlusion cancellation filter that is a filter for attenuating the occlusion.

9. The sound processing device according to claim 7, wherein the adjustment unit sets the target value as the occlusion cancellation amount when the amount of occlusion, which is the amplification amount of a peak corresponding to a peak in the sound spectrum of a self-voice signal, which is the signal of the user's own voice amplified by wearing the sound device, is greater than the target value for the frequency corresponding to the frequency of the peak.

10. The sound processing device according to claim 3, further comprising a noise cancellation unit that generates, based on the output sound signal, an acoustic signal for suppressing an acoustic signal of environmental sound around the user that has leaked into the sound device.

11. The sound processing device according to claim 10, wherein the feedback cancellation unit includes a howling cancellation filter that suppresses feedback occurring in the noise cancellation unit based on the output sound signal after adjusting for a delay caused by hearing aid processing by the hearing aid processing unit.

12. The sound processing device according to claim 4, further comprising a separation unit that separates the inner acoustic signal based on the outer acoustic signal into an outer-origin acoustic signal, which is an acoustic signal of the inner acoustic signal originating from the outer side, and an inner-origin acoustic signal, which is an acoustic signal of the inner acoustic signal originating from the inner side, and the occlusion cancellation unit generates the occlusion cancellation signal based on the inner-origin acoustic signal.

13. The sound processing device according to claim 12, wherein the separation unit updates a separation filter for performing the separation based on a probability that an own voice signal, which is a signal of the user's own voice, is detected from the inner sound signal.

14. The sound processing device according to claim 13, wherein the separation unit updates the separation filter only when the own voice signal is not detected from the inner sound signal, or reduces the amount of update of the separation filter as the probability of the own voice signal being detected increases.

15. The sound processing device according to claim 12, further comprising an external noise cancellation unit that generates an acoustic signal based on the external acoustic signal to suppress the acoustic signal of the environmental sound around the user that has leaked into the sound device.

16. The sound processing device according to claim 1, wherein the hearing aid processing unit suppresses an own voice signal, which is a signal of the user's own voice, from the outside sound signal based on the inside sound signal.

17. The sound processing device according to claim 16, wherein the hearing aid processing unit changes the amount of suppression of the own voice signal based on whether the own voice signal is detected from the inside acoustic signal.

18. The sound processing device according to claim 17, wherein the hearing aid processing unit changes the amount of suppression of the own voice signal so that the amount of suppression of the own voice signal increases as the probability of the own voice signal being detected from the inside acoustic signal increases.

19. An acoustic processing method executed by a computer, comprising: an acquisition process for acquiring an outer acoustic signal, which is a signal derived from sound propagating outside a user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid process for adjusting the volume of the outer acoustic signal based on the user's hearing characteristics measured in advance; an adjustment process for adjusting an occlusion cancellation amount, which is the amount by which occlusion caused by the volume of the inner acoustic signal being amplified when an acoustic device is worn on the user's ear, based on the adjustment amount of the volume of the outer acoustic signal by the hearing aid process; and an output process for outputting to the user an output sound in which the volume of the outer acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid process and the adjustment process.

20. An acoustic processing program for causing a computer to function as an acoustic processing device comprising: an acquisition unit that acquires an outer acoustic signal, which is a signal derived from sound propagating outside the user's ear canal, and an inner acoustic signal, which is a signal derived from sound propagating inside the ear canal; a hearing aid processing unit that adjusts the volume of the outer acoustic signal based on the user's hearing characteristics measured in advance; an adjustment unit that adjusts the occlusion cancellation amount, which is the amount by which occlusion caused by the volume of the inner acoustic signal being amplified when the acoustic device is worn on the user's ear, based on the amount of adjustment of the volume of the outer acoustic signal by the hearing aid processing unit; and an output unit that outputs to the user an output sound in which the volume of the outer acoustic signal and the occlusion cancellation amount have been adjusted by the hearing aid processing unit and the adjustment unit.

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