JP7395906B2 - Headphones, extra-head localization filter determination device, and extra-head localization filter determination method - Google Patents

Description

The present invention relates to headphones, an extra-head localization filter determination device, and an extra-head localization filter determination method.

As a sound image localization technique, there is an extra-head localization technique that localizes a sound image outside the listener's head using headphones. With out-of-head localization technology, the sound image is localized outside the head by canceling the characteristics from the headphones to the ears and providing the characteristics of the four channels from the stereo speakers to the ears.

In extra-head localization playback, measurement signals (impulse sounds, etc.) emitted from 2-channel (hereinafter referred to as "ch") speakers are recorded with a microphone (hereinafter referred to as "microphone") placed in the listener's (user's) ear. do. Then, the processing device creates a filter based on the collected sound signal obtained from the impulse response. By convolving the created filter into a 2ch audio signal, it is possible to realize out-of-head localization playback.

Furthermore, in order to generate a filter for canceling the characteristics from the headphones to the ear, the characteristics from the headphones to the ear to the eardrum (external auditory canal transfer function ECTF, also referred to as external auditory canal transfer characteristic) are measured using a microphone placed in the listener's own ear. Measure with.

Patent Document 1 discloses a binaural hearing device using an extrahead sound image localization filter. This device converts pre-measured spatial transfer functions of a large number of humans into feature parameter vectors corresponding to human auditory characteristics. Then, the device uses data that has been aggregated into a small number by performing clustering. Furthermore, the device performs clustering of the pre-measured spatial transfer function and the inverse transfer function of real-ear headphones based on human physical dimensions. Then, the data of the person closest to the centroid of each cluster is used.

Patent Document 2 discloses an extra-head localization filter determining device that includes headphones and a microphone unit. In Patent Document 1, a server device associates first preset data regarding spatial acoustic transfer characteristics from a sound source to a subject's ear with second preset data regarding external auditory canal transfer characteristics of the subject's ear. I remember. A user terminal is measuring measurement data regarding a user's ear canal transmission characteristics. A user terminal is transmitting user data based on measurement data to a server device. The server device compares the user data with a plurality of second preset data. The server device extracts the first preset data based on the comparison result.

Japanese Patent Application Publication No. 8-111899 Unexamined Japanese Patent Publication No. 2018-191208

In such extra-head localization processing, it is preferable to use an appropriate filter. Therefore, it is preferable to perform appropriate measurements.

The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide headphones, an extra-head localization filter determination device, and an extra-head localization filter determination method that can appropriately perform measurements.

The headphones according to the present embodiment include a headphone band, left and right housings provided on the headphone band, guide mechanisms provided on the left and right housings, and drivers disposed in the left and right housings, respectively. an actuator that moves the driver along the guide mechanism.

The headphones according to the present embodiment include a headphone band, left and right inner housings fixed to the headphone band, a plurality of drivers fixed to the left and right inner housings, and each arranged on the outside of the left and right inner housings. and an outer housing whose angle with respect to the inner housing is variable.

According to the present embodiment, it is possible to provide headphones, an extra-head localization filter determination device, and an extra-head localization filter determination method that can appropriately perform measurements.

FIG. 1 is a block diagram showing an extra-head localization processing device according to the present embodiment. FIG. 2 is a diagram showing the configuration of a measuring device that measures spatial acoustic transfer characteristics. FIG. 2 is a diagram showing the configuration of a measuring device that measures external auditory canal transmission characteristics. FIG. 1 is a diagram showing the overall configuration of an extra-head localization filter determination system according to the present embodiment. FIG. 3 is a schematic diagram showing the arrangement of drivers of headphones. FIG. 2 is a diagram showing the configuration of a server device of the extra-head localization filter determination system. It is a table showing the data structure of preset data stored in the server device. 7 is a table showing a data structure of preset data in Modification 1. FIG. FIG. 3 is a schematic diagram showing headphones in Embodiment 2. FIG. 7 is a table showing the data structure of preset data according to Embodiment 2. FIG. 3 is a table showing the data structure of preset data. FIG. 3 is a front view showing headphones of sensor example 1. FIG. 3 is a front view showing the wearing condition of subjects 1 with different facial widths. FIG. 7 is a front view showing headphones of sensor example 2. FIG. 3 is a front view showing the wearing condition of subjects 1 with different face lengths. FIG. 7 is a top view showing headphones of sensor example 3. FIG. 7 is a top view showing the mounting state with different swivel angles. FIG. 7 is a top view showing headphones of sensor example 4. FIG. 7 is a top view showing the mounting state with different hanger angles. It is a table showing preset data when shape data is used. FIG. 7 is a top view schematically showing headphones according to a fourth embodiment. FIG. 7 is a diagram showing a state in which the driver position has been changed in the headphones of Embodiment 4; FIG. 7 is a top view schematically showing headphones of Modification 2. FIG. 7 is a diagram for explaining a state in which headphones are worn according to modification 2; FIG. 3 is a diagram for explaining the arrangement of speakers and drivers.

(overview)
First, an overview of sound image localization processing will be explained. Here, extra-head localization processing, which is an example of a sound image localization processing device, will be described. The extra-head localization process according to the present embodiment performs extra-head localization processing using spatial acoustic transfer characteristics and external auditory canal transfer characteristics. Spatial acoustic transfer characteristics are transfer characteristics from a sound source such as a speaker to the ear canal. The external auditory canal transmission characteristic is the transmission characteristic from the entrance of the external auditory canal to the eardrum. In this embodiment, external auditory canal transmission characteristics are measured while headphones are being worn, and external localization processing is implemented using the measured data.

The extra-head localization process according to this embodiment is executed on a user terminal such as a personal computer (PC), a smart phone, or a tablet terminal. The user terminal is an information processing device that includes a processing means such as a processor, a storage means such as a memory or a hard disk, a display means such as a liquid crystal monitor, and an input means such as a touch panel, buttons, a keyboard, and a mouse. The user terminal has a communication function for transmitting and receiving data. Furthermore, an output means (output unit) having headphones or earphones is connected to the user terminal.

In order to obtain a high localization effect, it is preferable to measure the characteristics of the user himself/herself and generate an extra-head localization filter. A user's individual spatial sound transfer characteristic is generally determined in a listening room equipped with acoustic equipment such as speakers and the acoustic characteristics of the room. That is, the user needs to go to a listening room or prepare a listening room at the user's home or the like. Therefore, it may not be possible to appropriately measure the spatial acoustic transfer characteristics of an individual user.

Furthermore, even if a listening room is prepared by installing speakers in the user's home, the speakers may be installed asymmetrically, or the acoustic environment of the room may not be optimal for listening to music. In such cases, it is very difficult to measure appropriate spatial acoustic transfer characteristics at home.

On the other hand, the measurement of the external auditory canal transmission characteristics of an individual user is performed while the user is wearing a microphone unit and headphones. That is, if the user is wearing a microphone unit and headphones, the ear canal transfer characteristics can be measured. There is no need for the user to go to a listening room or to prepare a large-scale listening room at the user's home. Further, generation of a measurement signal for measuring the external auditory canal transfer characteristic, recording of a collected sound signal, etc. can be performed using a user terminal such as a smartphone or a PC.

As described above, it may be difficult to measure spatial acoustic transfer characteristics for individual users. Therefore, the extra-head localization processing system according to the present embodiment determines a filter according to the spatial sound transfer characteristic based on the measurement result of the external auditory canal transfer characteristic. That is, an extra-head localization processing filter suitable for the user is determined based on the measurement results of the user's individual ear canal transmission characteristics.

Specifically, the extrahead localization processing system includes a user terminal and a server device. The server device stores spatial acoustic transfer characteristics and ear canal transfer characteristics that are measured in advance for a plurality of subjects other than the user. That is, using a measurement device different from the user terminal, we measured spatial acoustic transfer characteristics using a speaker as a sound source (hereinafter also referred to as the first preliminary measurement), and measured ear canal transfer characteristics using headphones as a sound source ( (also referred to as a second preliminary measurement) is performed. The first preliminary measurement and the second preliminary measurement are performed on a person to be measured other than the user.

The server device stores first preset data according to the result of the first preliminary measurement and second preset data according to the result of the second preliminary measurement. By performing first and second preliminary measurements on a plurality of subjects, a plurality of first preset data and a plurality of second preset data are acquired. The server device stores first preset data regarding spatial acoustic transfer characteristics and second preset data regarding ear canal transfer characteristics in association with each other for each subject. The server device stores a plurality of first preset data and a plurality of second preset data in a database.

Furthermore, for an individual user who performs extra-head localization processing, only the external auditory canal transmission characteristics are measured using a user terminal (hereinafter referred to as user measurement). Similar to the second preliminary measurement, the user measurement is a measurement using headphones as a sound source. The user terminal obtains measurement data regarding ear canal transmission characteristics. The user terminal then transmits user data based on the measurement data to the server device. The server device compares the user data with each of the plurality of second preset data. Based on the comparison result, the server device determines second preset data having a high correlation with the user data from among the plurality of second preset data.

Then, the server device reads out the first preset data associated with the highly correlated second preset data. That is, the server device extracts first preset data suitable for the individual user from among the plurality of first preset data based on the comparison result. The server device transmits the extracted first preset data to the user terminal. Then, the user terminal performs extra-head localization processing using a filter based on the first preset data and an inverse filter based on user measurements.

Embodiment 1.
(External stereotaxic processing device)
First, FIG. 1 shows an extra-head localization processing device 100, which is an example of a sound field reproduction device according to the present embodiment. FIG. 1 is a block diagram of an extra-head localization processing device 100. The extra-head localization processing device 100 reproduces a sound field for the user U wearing the headphones 43. Therefore, the extra-head localization processing device 100 performs sound image localization processing on the Lch and Rch stereo input signals XL and XR. The Lch and Rch stereo input signals XL and XR are analog audio playback signals output from a CD (Compact Disc) player or the like, or digital audio data such as mp3 (MPEG Audio Layer-3). Note that the extra-head localization processing device 100 is not limited to a physically single device, and some processing may be performed by different devices. For example, part of the processing may be performed by a PC or the like, and the remaining processing may be performed by a DSP (Digital Signal Processor) or the like built into the headphones 43.

The extra-head localization processing device 100 includes an extra-head localization processing section 10 , a filter section 41 , a filter section 42 , and headphones 43 . The extra-head localization processing section 10, the filter section 41, and the filter section 42 constitute an arithmetic processing section 120, which will be described later, and can be specifically realized by a processor.

The extra-head localization processing unit 10 includes convolution calculation units 11 to 12, 21 to 22, and adders 24 and 25. The convolution calculation units 11-12, 21-22 perform convolution processing using spatial acoustic transfer characteristics. Stereo input signals XL and XR from a CD player or the like are input to the extra-head localization processing section 10. Spatial acoustic transfer characteristics are set in the extra-head localization processing unit 10. The extra-head localization processing unit 10 convolves the stereo input signals XL and XR of each channel with a spatial acoustic transfer characteristic filter (hereinafter also referred to as a spatial acoustic filter). The spatial acoustic transfer characteristic may be a head-related transfer function HRTF measured on the head or pinna of the subject, or may be a head-related transfer function of a dummy head or a third person.

A set of four spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs is defined as a spatial acoustic transfer function. The data used for convolution in the convolution calculation units 11, 12, 21, and 22 becomes a spatial acoustic filter. Each of the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs is measured using a measuring device described below.

Then, the convolution calculation unit 11 convolves the Lch stereo input signal XL with a spatial acoustic filter according to the spatial acoustic transfer characteristic Hls. The convolution operation unit 11 outputs convolution operation data to the adder 24. The convolution calculation unit 21 convolves the Rch stereo input signal XR with a spatial acoustic filter according to the spatial acoustic transfer characteristic Hro. The convolution operation unit 21 outputs convolution operation data to the adder 24. The adder 24 adds the two convolution calculation data and outputs the result to the filter section 41.

The convolution calculation unit 12 convolves the Lch stereo input signal XL with a spatial acoustic filter according to the spatial acoustic transfer characteristic Hlo. The convolution calculation unit 12 outputs the convolution calculation data to the adder 25. The convolution calculation unit 22 convolves the Rch stereo input signal XR with a spatial acoustic filter according to the spatial acoustic transfer characteristic Hrs. The convolution calculation unit 22 outputs the convolution calculation data to the adder 25. The adder 25 adds the two convolution calculation data and outputs the result to the filter section 42.

The filter sections 41 and 42 are provided with inverse filters that cancel headphone characteristics (characteristics between the headphone reproduction unit and the microphone). Then, the reproduced signal (convolution calculation signal) processed by the extra-head localization processing section 10 is convolved with an inverse filter. The filter section 41 convolves the Lch signal from the adder 24 with an inverse filter. Similarly, the filter unit 42 convolves the Rch signal from the adder 25 with an inverse filter. The inverse filter cancels the characteristics from the headphone unit to the microphone when the headphones 43 are worn. The microphone may be placed anywhere between the entrance to the ear canal and the eardrum. The inverse filter is calculated from the measurement results of the characteristics of the user U himself/herself.

The filter section 41 outputs the corrected Lch signal to the left unit 43L of the headphones 43. The filter section 42 outputs the corrected Rch signal to the right unit 43R of the headphones 43. User U is wearing headphones 43. Headphones 43 output Lch signals and Rch signals to user U. Thereby, a sound image localized outside the user's U head can be reproduced.

In this way, the extra-head localization processing device 100 performs extra-head localization processing using the spatial acoustic filters according to the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs and the inverse filter of the headphone characteristics. In the following description, the spatial acoustic filters according to the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs and the inverse filter of the headphone characteristics are collectively referred to as an extra-head localization processing filter. In the case of a 2-channel stereo reproduction signal, the extra-head localization filter is composed of four spatial acoustic filters and two inverse filters. Then, the extra-head localization processing device 100 executes extra-head localization processing by performing convolution calculation processing on the stereo reproduction signal using a total of six extra-head localization filters.

(Measuring device for spatial acoustic transfer characteristics)
A measuring device 200 that measures spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs will be described using FIG. 2. FIG. 2 is a diagram schematically showing a measurement configuration for performing a first preliminary measurement on the person to be measured 1. As shown in FIG.

As shown in FIG. 2, the measuring device 200 includes a stereo speaker 5 and a microphone unit 2. Stereo speakers 5 are installed in the measurement environment. The measurement environment may be a room in the user's U's home, an audio system sales store, a showroom, or the like. The measurement environment is preferably a listening room equipped with speakers and acoustics.

In this embodiment, the measurement processing device 201 of the measurement device 200 performs arithmetic processing to appropriately generate a spatial acoustic filter. The measurement processing device 201 includes, for example, a music player such as a CD player. The measurement processing device 201 may be a personal computer (PC), a tablet terminal, a smart phone, or the like. Further, the measurement processing device 201 may be a server device itself.

The stereo speaker 5 includes a left speaker 5L and a right speaker 5R. For example, a left speaker 5L and a right speaker 5R are installed in front of the person to be measured 1. The left speaker 5L and the right speaker 5R output impulse sounds and the like for performing impulse response measurements. Although the present embodiment will be described below assuming that the number of speakers serving as sound sources is two (stereo speakers), the number of sound sources used for measurement is not limited to two, and may be one or more. That is, the present embodiment can be similarly applied to a so-called multi-channel environment such as 1ch monaural, 5.1ch, 7.1ch, etc.

The microphone unit 2 is a stereo microphone having a left microphone 2L and a right microphone 2R. The left microphone 2L is installed in the left ear 9L of the person to be measured 1, and the right microphone 2R is installed in the right ear 9R of the person to be measured 1. Specifically, it is preferable to install the microphones 2L and 2R at positions from the entrance of the external auditory canal to the eardrum of the left ear 9L and right ear 9R. The microphones 2L and 2R collect the measurement signal output from the stereo speaker 5 to obtain a collected sound signal. The microphones 2L and 2R output collected sound signals to the measurement processing device 201. The person to be measured 1 may be a person or a dummy head. That is, in this embodiment, the person to be measured 1 includes not only a person but also a dummy head.

As described above, the impulse response is measured by measuring the impulse sound output from the left speaker 5L and right speaker 5R using the microphones 2L and 2R. The measurement processing device 201 stores the collected sound signal acquired by impulse response measurement in a memory or the like. As a result, the spatial sound transfer characteristic Hls between the left speaker 5L and the left microphone 2L, the spatial sound transfer characteristic Hlo between the left speaker 5L and the right microphone 2R, and the spatial sound between the right speaker 5R and the left microphone 2L. A transfer characteristic Hro and a spatial acoustic transfer characteristic Hrs between the right speaker 5R and the right microphone 2R are measured. That is, the left microphone 2L picks up the measurement signal output from the left speaker 5L, thereby acquiring the spatial sound transfer characteristic Hls. A spatial sound transfer characteristic Hlo is acquired by the right microphone 2R picking up the measurement signal output from the left speaker 5L. The left microphone 2L picks up the measurement signal output from the right speaker 5R, thereby obtaining the spatial sound transfer characteristic Hro. The spatial sound transfer characteristic Hrs is acquired by the right microphone 2R collecting the measurement signal output from the right speaker 5R.

The measuring device 200 also generates a spatial acoustic filter according to the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs from the left and right speakers 5L and 5R to the left and right microphones 2L and 2R based on the collected sound signal. Good too. For example, the measurement processing device 201 cuts out the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs using a predetermined filter length. The measurement processing device 201 may correct the measured spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs.

By doing so, the measurement processing device 201 generates a spatial acoustic filter used in the convolution calculation of the extra-head localization processing device 100. As shown in FIG. 1, the extra-head localization processing device 100 uses a spatial acoustic filter according to the spatial acoustic transfer characteristics Hls, Hlo, Hro, Hrs between the left and right speakers 5L, 5R and the left and right microphones 2L, 2R. External localization processing is performed using . That is, extra-head localization processing is performed by convolving the spatial acoustic filter with the audio reproduction signal.

The measurement processing device 201 performs similar processing on the collected sound signals corresponding to each of the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs. That is, the same processing is performed on each of the four sound pickup signals corresponding to the spatial sound transfer characteristics Hls, Hlo, Hro, and Hrs. Thereby, spatial acoustic filters corresponding to the spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs can be generated.

(Measurement of external auditory canal transmission characteristics)
Next, a measuring device 200 for measuring external auditory canal transmission characteristics will be described using FIG. 3. FIG. 3 shows a configuration for performing a second preliminary measurement on the person to be measured 1. As shown in FIG.

A microphone unit 2 and headphones 43 are connected to the measurement processing device 201 . The microphone unit 2 includes a left microphone 2L and a right microphone 2R. The left microphone 2L is attached to the left ear 9L of the person to be measured 1. The right microphone 2R is attached to the right ear 9R of the person to be measured 1. The measurement processing device 201 and the microphone unit 2 may be the same as the measurement processing device 201 and the microphone unit 2 in FIG. 2, or may be different.

The headphones 43 include a headphone band 43B, a left unit 43L, and a right unit 43R. Headphone band 43B connects left unit 43L and right unit 43R. The left unit 43L outputs sound toward the left ear 9L of the person to be measured 1. The right unit 43R outputs sound toward the right ear 9R of the person to be measured 1. The headphones 43 may be of any type, such as a closed type, an open type, a semi-open type, or a semi-closed type. The headphones 43 are worn by the person to be measured 1 with the microphone unit 2 in a state where the headphones 43 are worn. That is, the left unit 43L and right unit 43R of the headphones 43 are respectively attached to the left ear 9L and right ear 9R to which the left microphone 2L and right microphone 2R are attached. Headphone band 43B generates a biasing force that presses left unit 43L and right unit 43R against left ear 9L and right ear 9R, respectively.

The left microphone 2L picks up the sound output from the left unit 43L of the headphones 43. The right microphone 2R collects the sound output from the right unit 43R of the headphones 43. The microphone portions of the left microphone 2L and the right microphone 2R are arranged at sound collection positions near the external ear canal. The left microphone 2L and the right microphone 2R are configured so as not to interfere with the headphones 43. That is, the person to be measured 1 can wear the headphones 43 with the left microphone 2L and the right microphone 2R placed at appropriate positions of the left ear 9L and right ear 9R. Note that the left microphone 2L and the right microphone 2R may be built into the left unit 43L and right unit 43R of the headphones 43, respectively, or may be provided separately from the headphones 43.

The measurement processing device 201 outputs measurement signals to the left microphone 2L and right microphone 2R. As a result, the left microphone 2L and the right microphone 2R generate impulse sounds and the like. Specifically, the impulse sound output from the left unit 43L is measured by the left microphone 2L. The impulse sound output from the right unit 43R is measured by the right microphone 2R. In this manner, impulse response measurement is performed.

The measurement processing device 201 stores the collected sound signal based on the impulse response measurement in a memory or the like. As a result, the transfer characteristics between the left unit 43L and the left microphone 2L (i.e., the external auditory canal transfer characteristics of the left ear) and the transfer characteristics between the right unit 43R and the right microphone 2R (i.e., the external auditory canal transfer characteristics of the right ear). ) is obtained. Here, the measurement data of the external auditory canal transfer characteristic of the left ear acquired by the left microphone 2L is defined as measurement data ECTFL, and the measurement data of the external auditory canal transfer characteristic of the right ear acquired by the right microphone 2R is defined as measurement data ECTFR.

The measurement processing device 201 includes a memory that stores measurement data ECTFL and ECTFR, respectively. Note that the measurement processing device 201 generates an impulse signal, a TSP (Time Stretched Pulse) signal, or the like as a measurement signal for measuring the external auditory canal transfer characteristic or the spatial acoustic transfer characteristic. The measurement signal includes a measurement sound such as an impulse sound.

The measurement device 200 shown in FIGS. 2 and 3 measures the external auditory canal transfer characteristics and the spatial acoustic transfer characteristics of a plurality of subjects 1. In this embodiment, a first preliminary measurement using the measurement configuration shown in FIG. 2 is performed on a plurality of subjects 1. Similarly, a second preliminary measurement using the measurement configuration shown in FIG. 3 is performed on a plurality of subjects 1. Thereby, the external auditory canal transfer characteristic and the spatial sound transfer characteristic are measured for each person to be measured 1.

(External stereotaxic filter determination system)
Next, the extra-head localization filter determination system 500 according to the present embodiment will be described using FIG. 4. FIG. 4 is a diagram showing the overall configuration of the extra-head localization filter determination system 500. The extra-head localization filter determination system 500 includes a microphone unit 2, headphones 43, an extra-head localization processing device 100, and a server device 300.

The extra-head localization processing device 100 and the server device 300 are connected via a network 400. The network 400 is, for example, a public network such as the Internet or a mobile phone communication network. The extra-head localization processing device 100 and the server device 300 can communicate wirelessly or by wire. Note that the extrahead localization processing device 100 and the server device 300 may be an integrated device.

As shown in FIG. 1, the extra-head localization processing device 100 serves as a user terminal that outputs a reproduced signal that has undergone extra-head localization processing to the user U. Furthermore, the external head localization processing device 100 measures the external auditory canal transmission characteristics of the user U. Therefore, the microphone unit 2 and headphones 43 are connected to the extra-head localization processing device 100. The extra-head localization processing device 100 performs impulse response measurement using the microphone unit 2 and headphones 43, similar to the measurement device 200 of FIG. Note that the microphone unit 2 and the headphones 43 may be wirelessly connected using BlueTooth (registered trademark) or the like.

The extra-head localization processing device 100 includes an impulse response measurement section 111, an ECTF characteristic acquisition section 112, a transmission section 113, a reception section 114, an arithmetic processing section 120, an inverse filter calculation section 121, and a filter storage section 122. , switch 124. Note that when the extra-head localization processing device 100 and the server device 300 are integrated, the device may include an acquisition section that acquires user data instead of the reception section 114.

The switch 124 switches between user measurement and extra-head localization playback. That is, in the case of user measurement, the switch 124 connects the headphones 43 and the impulse response measurement section 111. In the case of extra-head localization playback, the switch 124 connects the headphones 43 to the arithmetic processing section 120.

The impulse response measurement unit 111 outputs a measurement signal that becomes an impulse sound to the headphones 43 in order to perform user measurement. The microphone unit 2 picks up the impulse sound output by the headphones 43. The microphone unit 2 outputs the collected sound signal to the impulse response measurement section 111. Note that the impulse response measurement is the same as the explanation of FIG. 3, so the explanation will be omitted as appropriate. That is, the extrahead localization processing device 100 has the same function as the measurement processing device 201 in FIG. 3. The impulse response measurement unit 111, which includes the extra-head localization processing device 100, the microphone unit 2, and the headphones 43 to form a measurement device that performs user measurements, performs A/D conversion, synchronous addition processing, etc. on the collected sound signal. You may go.

Through the impulse response measurement, the impulse response measurement unit 111 obtains measurement data ECTF regarding the external auditory canal transfer characteristics. The measurement data ECTF includes measurement data ECTFL regarding the external auditory canal transmission characteristics of the left ear 9L of the user U, and measurement data ECTFR regarding the external auditory canal transmission characteristics of the right ear 9R.

The ECTF characteristic acquisition unit 112 acquires the characteristics of the measurement data ECTFL and ECTFR by performing predetermined processing on the measurement data ECTFL and ECTFR. For example, the ECTF characteristic acquisition unit 112 calculates the frequency amplitude characteristic and the frequency phase characteristic by performing a discrete Fourier transform. Furthermore, the ECTF characteristic acquisition unit 112 may calculate the frequency amplitude characteristic and the frequency phase characteristic not only by discrete Fourier transform but also by means of converting a discrete signal into a frequency domain, such as discrete cosine transform. Frequency power characteristics may be used instead of frequency amplitude characteristics.

The external auditory canal transmission characteristics measured by the user will be described using FIG. 5. FIG. 5 is a schematic diagram showing the arrangement of drivers of headphones 43 used for user measurements. The left unit 43L and the right unit 43R of the headphones 43 each have a housing 46. Two drivers 45f and 45m are provided in the housing 46. The housing 46 is a case that holds two drivers 45f and 45m. The left unit 43L and the right unit 43R are arranged symmetrically.

The drivers 45f and 45m have an actuator, a diaphragm, and the like, and can output sound. The actuator is, for example, a voice coil motor or a piezoelectric element, and converts an electrical signal into vibration. The drivers 45f and 45m can independently output sound.

The driver 45m and the driver 45f are arranged at different positions. For example, the driver 45m is placed right next to the external ear holes of the left ear 9L and right ear 9R. The driver 45f is arranged in front of the driver 45m. The position where the driver 45f is located is defined as a first position, and the position where the driver 45m is located is defined as a second position. The first position is in front of the second position.

The driver 45m and the driver 45f can output measurement signals at different timings. For the left ear 9L, an ear canal transfer characteristic M_ECTFL from the driver 45m of the left unit 43L to the left microphone 2L, and an ear canal transfer characteristic F_ECTFL from the driver 45f of the left unit 43L to the left microphone 2L are measured. For the right ear 9R, an ear canal transfer characteristic M_ECTFR from the driver 45m of the right unit 43R to the right microphone 2R, and an ear canal transfer characteristic F_ECTFL from the driver 45f of the right unit 43R to the right microphone 2R are measured.

The ear canal transfer characteristic F_ECTFL is a transfer characteristic from the first position of the left unit 43L to the microphone 2L. The ear canal transfer characteristic F_ECTFR is a transfer characteristic from the first position of the right unit 43R to the microphone 2R. The ear canal transfer characteristic M_ECTFL is a transfer characteristic from the second position of the left unit 43L to the microphone 2L. The ear canal transfer characteristic M_ECTFR is a transfer characteristic from the second position of the right unit 43R to the microphone 2R. The ear canal transfer characteristics F_ECTFL and F_ECTFR are referred to as first ear canal transfer characteristics or measurement data thereof. The ear canal transfer characteristics M_ECTFL and M_ECTFR are referred to as second ear canal transfer characteristics or measurement data thereof. The first ear canal transfer characteristic and the second ear canal transfer characteristic are measured by impulse response measurement using the microphone unit 2 and headphones 43.

The driver 45f is preferably arranged at a position corresponding to the arrangement of the stereo speakers 5 in FIG. For example, as shown in FIG. 5, assume that the front of the person to be measured 1 is set at 0°, and the left speaker 5L is installed in the direction of the opening angle θ. In this case, it is preferable that the direction from the microphone 2L toward the driver 45f be parallel to the direction of the opening angle θ. That is, in a top view, it is preferable that the direction from the center O of the head of the person to be measured 1 toward the speaker 5L and the direction from the microphone 2L toward the driver 45f be parallel. Note that when the stereo speakers 5 are placed in front of the person to be measured 1, the aperture angle θ is in the range of 0 to 90°, and is preferably 30°. The right speaker 5R and the driver 45f of the right unit 43R are also arranged in the same manner.

The driver 45m is placed on the side of the external auditory canal. The driver 45m is preferably located at the same location and of the same type as the driver of the headphones 43 that performs extra-head localization playback.

The transmitting unit 113 transmits user data regarding the external auditory canal transmission characteristics to the server device 300. The user data is data based on the first ear canal transmission characteristics F_ECTFL and F_ECTFR. Note that the user data may be time domain data or frequency domain data. The user data may be the whole or part of the frequency amplitude characteristic. Alternatively, the user data may be a feature amount extracted from frequency amplitude characteristics.

The inverse filter calculation unit 121 calculates an inverse filter based on the second ear canal transfer characteristics M_ECTFL and M_ECTFR. For example, the inverse filter calculation unit 121 corrects the frequency amplitude characteristics and frequency phase characteristics of the second ear canal transfer characteristics M_ECTFL and M_ECTFR. The inverse filter calculation unit 121 calculates a time signal using frequency characteristics and phase characteristics by inverse discrete Fourier transform. The inverse filter calculation unit 121 calculates an inverse filter by cutting out the time signal at a predetermined filter length.

As mentioned above, the inverse filter is a filter that cancels headphone characteristics (characteristics between the headphone playback unit and the microphone). The filter storage unit 122 stores the left and right inverse filters calculated by the inverse filter calculation unit 121. Note that a known method can be used to calculate the inverse filter, so a detailed explanation will be omitted.

Next, the configuration of the server device 300 will be explained using FIG. 6. FIG. 6 is a block diagram showing the control configuration of the server device 300. The server device 300 includes a receiving section 301, a comparing section 302, a data storage section 303, an extracting section 304, and a transmitting section 305. The server device 300 serves as a filter determining device that determines a spatial acoustic filter based on the external auditory canal transfer characteristics. Note that when the extrahead localization processing device 100 and the server device 300 are integrated, the device does not need to include the transmitter 305.

Note that the server device 300 is a computer equipped with a processor, a memory, etc., and performs the following processing according to a program. Further, the server device 300 is not limited to a single device, but may be realized by a combination of two or more devices, or may be a virtual server such as a cloud server. The data storage unit that stores data, and the comparison unit 302 and extraction unit 304 that perform data processing may be physically different devices.

The receiving unit 301 receives user data transmitted from the extra-head localization processing device 100. The receiving unit 301 performs processing (for example, demodulation processing) on the received user data according to the communication standard. The comparison unit 302 compares the user data with preset data stored in the data storage unit 303. Here, the receiving unit 301 receives the first external auditory canal transfer characteristics F_ECTFL and F_ECTFR measured by the user measurement as user data. The user data of the first ear canal transfer characteristics F_ECTFL and F_ECTFR are assumed to be user data F_ECTFL_U and F_ECTFR_U.

The data storage unit 303 is a database that stores data regarding a plurality of subjects measured in preliminary measurements as preset data. The data stored in the data storage unit 303 will be explained with reference to FIG. 7. FIG. 7 is a table showing data stored in the data storage unit 303.

The data storage unit 303 stores preset data for each of the left and right ears of the subject. Specifically, the data storage unit 303 has a table format in which the subject ID, left and right ears, first ear canal transfer characteristic, spatial acoustic transfer characteristic 1, and spatial acoustic transfer characteristic 2 are arranged in one row. There is. Note that the data format shown in FIG. 7 is an example, and instead of a table format, a data format in which objects of each parameter are associated and held using tags or the like may be adopted.

The data storage unit 303 stores two data sets for one person A. That is, the data storage unit 303 stores a data set related to the left ear of the person A and a data set related to the right ear of the person A.

One data set includes a subject ID, left and right ears, a first external auditory canal transfer characteristic, a spatial acoustic transfer characteristic 1, and a spatial acoustic transfer characteristic 2. The first ear canal transmission characteristic is data based on a second preliminary measurement by the measuring device 200 shown in FIG. 3. This is the frequency amplitude characteristic of the first external auditory canal transmission characteristic from the first position in front of the external auditory canal to the microphones 2L and 2R.

The first external auditory canal transfer characteristic of the left ear of the person A is indicated as the first external auditory canal transfer characteristic F_ECTFL_A, and the first external auditory canal transfer characteristic of the right ear of the subject A is indicated as the first external auditory canal transfer characteristic F_ECTFR_A. It shows. The first external auditory canal transfer characteristic of the left ear of the person B is indicated as the first external auditory canal transfer characteristic F_ECTFL_B, and the first external auditory canal transfer characteristic of the right ear of the subject B is indicated as the first external auditory canal transfer characteristic F_ECTFR_B. It shows. The first external auditory canal transmission characteristic is data measured using a driver 45f placed in front of the external auditory canal, as shown in FIG. The headphones 43 and driver 45f used for the user measurement and the second preliminary measurement are preferably of the same type, but may be of different types.

Spatial acoustic transfer characteristic 1 and spatial acoustic transfer characteristic 2 are data based on first preliminary measurement by measuring device 200 shown in FIG. 2. In the case of the left ear of the person A, the spatial acoustic transfer characteristic 1 is Hls_A, and the spatial acoustic transfer characteristic 2 is Hro_A. In the case of the right ear of the person A, the spatial acoustic transfer characteristic 1 is Hrs_A, and the spatial acoustic transfer characteristic 2 is Hlo_A. In this way, two spatial sound transfer characteristics related to one ear are paired. For the left ear of person B, Hls_B and Hro_B are a pair, and for the right ear of person B, Hrs_B and Hlo_B are a pair. Spatial acoustic transfer characteristic 1 and spatial acoustic transfer characteristic 2 may be data after being cut out by the filter length, or may be data before being cut out by the filter length.

Regarding the left ear of the person to be measured, the first ear canal transfer characteristic F_ECTFL_A, the spatial acoustic transfer characteristic Hls_A, and the spatial acoustic transfer characteristic Hro_A are associated with each other to form one data set. Similarly, for the right ear of the person A, the first ear canal transfer characteristic F_ECTFR_A, the spatial acoustic transfer characteristic Hrs_A, and the spatial acoustic transfer characteristic Hlo_A are associated with each other to form one data set. Similarly, for the left ear of the person to be measured, the first ear canal transfer characteristic F_ECTFL_B, the spatial acoustic transfer characteristic Hls_B, and the spatial acoustic transfer characteristic Hro_B are associated to form one data set. Similarly, for the right ear of the person to be measured, the first ear canal transfer characteristic F_ECTFL_B, the spatial acoustic transfer characteristic Hrs_B, and the spatial acoustic transfer characteristic Hlo_B are associated with each other to form one data set.

Note that the pair of spatial acoustic transfer characteristics 1 and 2 is assumed to be first preset data. That is, spatial acoustic transfer characteristic 1 and spatial acoustic transfer characteristic 2 constituting one data set are set as first preset data. The first external auditory canal transmission characteristic constituting one data set is set as second preset data. One data set includes first preset data and second preset data. The data storage unit 303 stores the first preset data and the second preset data in association with each other for each of the left and right ears of the subject.

Here, it is assumed that the first and second preliminary measurements have been performed on n (n is an integer of 2 or more) subjects 1 in advance. In this case, the data storage unit 303 stores 2n data sets for both ears. The first ear canal transfer characteristics stored in the data storage unit 303 are shown as first ear canal transfer characteristics F_ECTFL_A to first ear canal transfer characteristics F_ECTFL_N, and first ear canal transfer characteristics F_ECTFR_A to first ear canal transfer characteristics F_ECTFR_N.

The comparison unit 302 compares the user data F_ECTFL_U with each of the first ear canal transmission characteristics F_ECTFL_A to F_ECTFL_N and F_ECTFR_A to F_ECTFR_N. Then, the comparison unit 302 selects one of the 2n first ear canal transfer characteristics F_ECTFL_A to F_ECTFL_N and F_ECTFR_A to F_ECTFR_N that is most similar to the user data F_ECTFL_U. Here, the correlation between two frequency amplitude characteristics is calculated as a similarity score. The comparison unit 302 selects the first external auditory canal transfer characteristic data set that has the highest similarity score to the user data. Here, assuming that the left ear of the person to be measured l is selected, the selected first external auditory canal transmission characteristic is defined as the left selection characteristic F_ECTFL_l.

Similarly, the comparison unit 302 compares the user data F_ECTFR_U with each of the first ear canal transmission characteristics F_ECTFL_A to F_ECTFL_N and F_ECTFR_A to F_ECTFR_N. Then, the comparison unit 302 selects one of the 2n first ear canal transfer characteristics F_ECTFL_A to F_ECTFL_N and F_ECTFR_A to F_ECTFR_N that is most similar to the user data F_ECTFR_U. Here, it is assumed that the right ear of the person to be measured m is selected, and the selected first external auditory canal transmission characteristic is defined as the right selection characteristic F_ECTFR_m.

The comparison unit 302 outputs the comparison result to the extraction unit 304. Specifically, the subject ID of the second preset data with the highest similarity score and the left and right ears are output to the extraction unit 304. The extraction unit 304 extracts first preset data based on the comparison result.

The extraction unit 304 reads out the spatial acoustic transfer characteristic corresponding to the left selection characteristic F_ECTFL_l from the data storage unit 303 . The extraction unit 304 refers to the data storage unit 303 and extracts the spatial acoustic transfer characteristic Hls_l and the spatial acoustic transfer characteristic Hro_l of the left ear of the person to be measured l.

Similarly, the extraction unit 304 reads out the spatial acoustic transfer characteristic corresponding to the right selection characteristic F_ECTFR_m from the data storage unit 303 . The extraction unit 304 refers to the data storage unit 303 and extracts the spatial acoustic transfer characteristic Hrs_m and the spatial acoustic transfer characteristic Hlo_m of the left ear of the person m.

In this way, the comparison unit 302 compares the user data with the plurality of second preset data. Then, the extraction unit 304 extracts first preset data suitable for the user based on the comparison result between the second preset data and the user data.

Then, the transmitting unit 305 transmits the first preset data extracted by the extracting unit 304 to the extra-head localization processing device 100. The transmitter 305 performs processing (for example, modulation processing) on the first preset data according to a communication standard, and transmits the data. Here, for the left ear, the spatial acoustic transfer characteristic Hls_l and the spatial acoustic transfer characteristic Hro_l are extracted as the first preset data, and for the right ear, the spatial acoustic transfer characteristic Hrs_m and the spatial acoustic transfer characteristic Hlo_m are extracted as the first preset data. It has been extracted as preset data. Therefore, the transmitting unit 305 transmits the spatial acoustic transfer characteristic Hls_l, the spatial acoustic transfer characteristic Hro_l, the spatial acoustic transfer characteristic Hrs_m, and the spatial acoustic transfer characteristic Hlo_m to the extra-head localization processing device 100.

Returning to the explanation of FIG. 4. The receiving section 114 receives the first preset data transmitted from the transmitting section 305. The receiving unit 114 performs processing (for example, demodulation processing) on the received first preset data in accordance with the communication standard. The receiving unit 114 receives spatial acoustic transfer characteristics Hls_l and spatial acoustic transfer characteristics Hro_l as first preset data regarding the left ear, and receives spatial acoustic transfer characteristics Hrs_m and spatial acoustic transfer characteristics as first preset data regarding the right ear. Receive Hlo_m.

The filter storage unit 122 then stores the spatial acoustic filter based on the first preset data. That is, the spatial sound transfer characteristic Hls_l becomes the user U's spatial sound transfer characteristic Hls, and the spatial sound transfer characteristic Hro_l becomes the user U's spatial sound transfer characteristic Hro. Similarly, the spatial sound transfer characteristic Hrs_m becomes the spatial sound transfer characteristic Hrs of the user U, and the spatial sound transfer characteristic Hlo_m becomes the spatial sound transfer characteristic Hlo of the user U.

Note that when the first preset data is data after being cut out by the filter length, the extra-head localization processing device 100 stores the first preset data as it is as a spatial acoustic filter. For example, the spatial sound transfer characteristic Hls_l becomes the spatial sound transfer characteristic Hls of the user U. If the first preset data is data before being cut out at the filter length, the extra-head localization processing device 100 performs processing to cut out the spatial acoustic transfer characteristic at the filter length.

The arithmetic processing unit 120 performs arithmetic processing using a spatial acoustic filter according to four spatial acoustic transfer characteristics Hls, Hlo, Hro, and Hrs, and an inverse filter. The arithmetic processing section 120 includes the extra-head localization processing section 10 shown in FIG. 1, a filter section 41, and a filter section 42. Therefore, the arithmetic processing unit 120 performs the above-mentioned convolution processing and the like on the stereo input signal using four spatial acoustic filters and two inverse filters.

In this way, the data storage unit 303 stores the first preset data and the second preset data in association with each other for each subject 1. The first preset data is data regarding the spatial acoustic transfer characteristics of the person to be measured 1. The second preset data is data regarding the first external auditory canal transmission characteristic of the subject 1.

Comparison unit 302 compares the user data with second preset data. The user data is data regarding the first external auditory canal transmission characteristic obtained through user measurements. Then, the comparison unit 302 determines the subject 1 and the left and right ears that are similar to the user's first external auditory canal transmission characteristic.

The extraction unit 304 reads out first preset data corresponding to the determined subject and the left and right ears. The transmitter 305 then transmits the extracted first preset data to the extra-head localization processing device 100. The extra-head localization processing device 100, which is a user terminal, performs extra-head localization processing using a spatial acoustic filter based on first preset data and an inverse filter based on measurement data.

By doing so, the user U can determine an appropriate filter without measuring the spatial acoustic transfer characteristics. Therefore, there is no need for the user to go to a listening room or the like, or to install a speaker or the like in the user's home. User measurements are performed while wearing headphones. That is, if the user U wears headphones and a microphone, the user's individual ear canal transmission characteristics can be measured. Therefore, extra-head localization with high localization effects can be achieved using a simple method. Note that it is preferable that the headphones 43 used for user measurement and external localization listening are of the same type.

Furthermore, in this embodiment, two drivers 45m and 45f are used. The second ear canal transfer characteristic measured by the driver 45m is used to generate the inverse filter. Furthermore, the first ear canal transfer characteristic measured by the driver 45f is used to determine the spatial acoustic filter. That is, the spatial acoustic filter is determined by matching the user data regarding the first ear canal transmission characteristic and the second preset data. By doing so, a more appropriate extra-head localization filter can be used.

A stereo speaker 5 placed in front of the person to be measured 1 is used to generate the spatial acoustic filter, that is, to measure the spatial acoustic transfer characteristic. The spatial sound transfer characteristic is measured by the microphone unit 2 collecting the measurement signal arriving from diagonally in front. A driver 45f placed in front of the external auditory canal is used to measure the first external auditory canal transmission characteristic. According to this embodiment, the measurement signal for measuring the first external auditory canal transfer characteristic and the measurement signal for measuring the spatial acoustic transfer characteristic can have the same incident angle.

The direction from the microphone to the first position is the direction along the direction from the person to be measured to the speaker. By doing so, it becomes easier to infer the relationship between the spatial acoustic transfer characteristics and the external auditory canal transfer characteristics, so that matching accuracy can be improved. It becomes possible to perform extra-head localization processing using a more appropriate spatial acoustic filter.

On the other hand, the second external auditory canal transfer characteristic measured by the driver 45m is used to generate the inverse filter. When performing extra-head localization processing, the driver of the headphones 43 is usually located right next to the external ear canal. Therefore, it becomes possible to perform extra-head localization processing using a more appropriate inverse filter.

Note that the headphones 43 for user measurement and the headphones 43 for second pre-measurement are preferably of the same type, but may be of different types. That is, the user-measured driver 45f and the second pre-measured driver 45f can be of different types, and can also be placed in different positions. The incident angles of the measurement signals in the first preliminary measurement, the second preliminary measurement, and the user measurement are preferably the same, but may be different.

Further, different headphones 43 may be used to measure the first ear canal transmission characteristic and the second ear canal transmission characteristic. For example, the headphones 43 having only the driver 45f may be used to measure the first ear canal transfer characteristic, and the headphones 43 having only the driver 45m may be used to measure the second ear canal transfer characteristic. By preparing two types of headphones 43, it is possible to perform user measurements using the headphones 43 having one driver on each side.

Furthermore, with the method according to the present embodiment, there is no need to perform an auditory test to listen to a large number of preset characteristics, or to measure physical characteristics in detail. Therefore, the burden on the user can be reduced and convenience can be improved. By comparing the data of the person being measured and the user, it is possible to select a person having similar characteristics. Since the extraction unit 304 extracts the first preset data of the ear of the selected subject, a high extra-head localization effect can be expected.

By doing so, an appropriate filter can be determined without the user having to measure the spatial acoustic transfer characteristics. Therefore, convenience can be improved. Further, the extraction unit 304 may extract two or more first preset data. The user may determine the optimal extra-head localization filter based on the results of the auditory test. In this case as well, the number of hearing tests can be reduced, so the burden on the user can be reduced.

Modification example 1.
In the first modification, the first and second ear canal transfer characteristics are used for matching the ear canal transfer characteristics between the user data and the second preset data. Therefore, the transmitter 113 transmits not only the first ear canal transfer characteristics F_ECTFL and F_ECTFR but also the second ear canal transfer characteristics M_ECTFL and M_ECTFR as user data. The extra-head localization processing device 100 transmits user data regarding the first and second external auditory canal transmission characteristics to the server device 300. The preset data stored in the server device 300 will be explained using FIG. 8.

FIG. 8 is a table showing preset data in Modification 1. The second preset data includes first and second ear canal transmission characteristics. The second preset data includes first and second ear canal transmission characteristics. Regarding the left ear of the person A, the first ear canal transfer characteristic F_ECTFL_A, the second ear canal transfer characteristic M_ECTFL_A, the spatial acoustic transfer characteristic Hls_A, and the spatial acoustic transfer characteristic Hro_A are associated, and one data is created. It is a set. Similarly, for the right ear of the person A, the first ear canal transfer characteristic F_ECTFR_A, the second ear canal transfer characteristic M_ECTFR_A, the spatial acoustic transfer characteristic Hrs_A, and the spatial acoustic transfer characteristic Hlo_A are associated, It is one data set.

In this embodiment, the first and second ear canal transmission characteristics are the second preset data. The comparison unit 302 of the server device 300 calculates the correlation between the user data and the preset data for each of the first and second external auditory canal transmission characteristics. That is, the comparison unit 302 determines the first correlation between the user data and the preset data regarding the first external auditory canal transmission characteristic. Similarly, the comparison unit 302 obtains a second correlation between the user data and the preset data for each of the second ear canal transmission characteristics.

The comparison unit 302 calculates a similarity score based on the two correlations. The similarity score can be, for example, a simple average or a weighted average of the first and second correlations. The extraction unit 304 extracts the first preset data of the dataset with the highest similarity score. By performing matching using two or more ear canal transmission characteristics, preset data suitable for the user can be extracted. Extra-head localization filters can be determined with higher accuracy.

Embodiment 2.
Headphones 43 used in this embodiment will be explained using FIG. 9. In the embodiment, the position of the driver 45 in the headphones 43 is variable. Note that the overall basic configuration of the extra-head localization filter determination system 500 is the same as that in Embodiment 1, so a description thereof will be omitted.

The relative position of the driver 45 with respect to the left microphone 2L and right microphone 2R can be changed. For example, the position of the driver 45 can be adjusted within the housing 46. The angle of incidence at which the measurement signal enters the microphone can be set to any angle. Then, the measurement is performed with the driver 45 in the first position, the second position, and the third position. In FIG. 9, the driver 45 in the first position is shown by a solid line, and the drivers 45 in the second and third positions are shown by broken lines as drivers 45m and 45b.

The first position and the second position are the same positions as in the first embodiment. As in the first embodiment, the ear canal transfer characteristics obtained by measurement at the first position are referred to as first ear canal transfer characteristics F_ECTFL, F_ECTFR, and the ear canal transfer characteristics obtained by measurement at the second position are referred to as first ear canal transfer characteristics F_ECTFL, F_ECTFR. The external auditory canal transmission characteristics M_ECTFL and M_ECTFR of 2 are assumed to be M_ECTFL and M_ECTFR. The third position is further rearward than the second position. The third position is behind the external auditory foramen. The external auditory canal transmission characteristics obtained by measurement at the third position are referred to as third external auditory canal transmission characteristics B_ECTFL and B_ECTFR.

In this embodiment, all measurement data of the first ear canal transfer characteristics F_ECTFL, F_ECTFR, the second ear canal transfer characteristics M_ECTFL, M_ECTFR, and the third ear canal transfer characteristics B_ECTFL, B_ECTFR are stored in the server device 300 as user data. Sent.

In this embodiment, extra-head localization processing is performed using a 5.1ch reproduction signal. In the case of 5.1ch, there are 6 speakers. That is, the measurement environment of the measurement device 200 includes a center speaker (front speaker), a right front speaker, a left front speaker, a right rear speaker, a left rear speaker, and a bass subwoofer speaker. Therefore, a center speaker, a left rear speaker, a right rear speaker, and a subwoofer speaker are added to the measuring device 200 shown in FIG. 2. The center speaker is placed in front of the person to be measured 1 . The center speaker is arranged, for example, between the left front speaker and the right front speaker.

The spatial sound transmission characteristics from the left front speaker to the left ear and the right ear are assumed to be Hls and Hlo as in the first embodiment. The spatial sound transmission characteristics from the right front speaker to the left ear and the right ear are assumed to be Hro and Hrs as in the first embodiment. Let the spatial sound transmission characteristics from the center speaker to the left ear and right ear be CHl and CHr. The spatial sound transmission characteristics from the left rear speaker to the left ear and right ear are defined as SHls and SHlo. The spatial sound transmission characteristics from the right rear speaker to the left ear and the right ear are defined as SHro and SHrs. Let SWHl and SWHr be the spatial sound transmission characteristics from the subwoofer speaker for bass output to the left ear and the right ear.

The server device 300 determines the spatial acoustic transfer characteristics of each speaker by performing matching. The ear canal transmission characteristics used for matching are changed depending on the speaker. For example, as in the first embodiment, the first external auditory canal transmission characteristic is used for matching for the left front speaker and the right front speaker. In this case, the preset data will be similar to that shown in FIG. Alternatively, as shown in FIG. 8, the first and second ear canal transmission characteristics may be used for matching.

For the left rear speaker and the right rear speaker, a third ear canal transmission characteristic from the third position to the microphone is used for matching. The third position is the position shown by the driver 45b in FIG. 9, and is a position behind the external ear canal. It is preferable that the incident angle of the measurement signal from the driver 45b be aligned with the installation direction of the left rear speaker and the right rear speaker. The process of determining the spatial sound transfer characteristics SHls, SHro or the spatial sound transfer characteristics SHlo, SHrs will be described below.

FIG. 10 is a table showing preset data for determining the spatial sound transfer characteristics SHls, SHro or the spatial sound transfer characteristics SHlo, SHrs. Regarding the left ear of the person A, the second ear canal transfer characteristic M_ECTFL_A, the third ear canal transfer characteristic B_ECTFL_A, the spatial acoustic transfer characteristic SHls_A, and the spatial acoustic transfer characteristic SHro_A are associated to form one data set. It becomes. Similarly, for the right ear of the person A, the second ear canal transfer characteristic M_ECTFR_A, the third ear canal transfer characteristic B_ECTFR_A, the spatial sound transfer characteristic SHrs_A, and the spatial sound transfer characteristic SHlo_A are associated, and 1 There are two data sets.

The comparison unit 302 then determines the correlation between the second preset data and the user data regarding the second and third external auditory canal transmission characteristics. The extraction unit 304 extracts first preset data regarding the spatial sound transfer characteristics SHls, SHlo or the spatial sound transfer characteristics SHro, SHrs using the similarity score according to the correlation. The correlation between user data and preset data regarding the second ear canal transfer characteristic is defined as a second correlation, and the correlation between the user data and preset data regarding the third ear canal transfer characteristic is defined as a third correlation.

The comparison unit 302 calculates a similarity score based on the two correlations. The similarity score can be, for example, a simple average or a weighted average of the second and third correlations. The extraction unit 304 extracts the first preset data of the dataset with the highest similarity score. By performing matching using two or more ear canal transmission characteristics, preset data suitable for the user can be extracted. Extra-head localization filters can be determined with higher accuracy.

In this way, the second preset data associated with the first preset data is changed depending on the relative position of the speaker with respect to the person to be measured 1. That is, for the left front speaker and right front speaker located in front of the user, the first external auditory canal transmission characteristic measured using the driver 45 located in front of the external auditory canal is used for matching. For the left rear speaker and right rear speaker located behind the user, the third external auditory canal transmission characteristic measured using the driver 45b located behind the external auditory canal is used for matching.

Matching is similarly performed using one or more ear canal transmission characteristics for the spatial sound transmission characteristics CHl and CHr from the center speaker to the left ear and the right ear. Similarly, matching is performed using one or more ear canal transfer characteristics for the spatial sound transfer characteristics SWHl and SWHr from the subwoofer speaker for bass output to the left ear and the right ear. Since the subwoofer speaker and the center speaker are placed in front of the person to be measured 1, it is preferable to take measurements with the driver 45 placed in front of the external ear canal. Note that since the frequency band of the subwoofer speaker has low directivity, matching may be performed using the ear canal transfer characteristics measured at any driver position, regardless of the positional relationship between the person to be measured 1 and the subwoofer speaker. .

For speakers located in front of the person to be measured 1, matching is performed using the ear canal transmission characteristics from the first position to the microphone. For speakers located behind the person to be measured 1, matching is performed using the ear canal transmission characteristics from the third position to the microphone. This allows the incident angles of the measurement signals to be made the same, so it is possible to set a more appropriate extra-head localization filter. The angle of incidence of the measurement signal from the driver and the angle of incidence of the measurement signal from the speaker do not need to completely match.

Of course, it is possible to use not only 5.1ch speakers but also 7.1ch and 9.1ch speakers. In this case as well, spatial acoustic filters from each speaker to the left and right ears can be determined by matching the ear canal transfer characteristics. Then, the weight of the weighted addition may be adjusted depending on the arrangement of the speakers.

Further, when three or more ear canal transfer characteristics are measured, three or more ear canal transfer characteristics may be used for matching. In this case, the correlations may be weighted and added using weights depending on the positions of the speakers. FIG. 11 shows preset data using three ear canal transmission characteristics for matching.

In FIG. 11, the second preset data includes the first to third ear canal transmission characteristics. Regarding the left ear of the person A, the first ear canal transfer characteristic F_ECTFL_A, the second ear canal transfer characteristic M_ECTFL_A, the third ear canal transfer characteristic B_ECTFL_A, the spatial acoustic transfer characteristic Hls_A, and the spatial acoustic transfer characteristic Hro_A. are associated to form one data set. Similarly, for the right ear of the person A, the first ear canal transfer characteristic F_ECTFR_A, the second ear canal transfer characteristic M_ECTFR_A, the third ear canal transfer characteristic B_ECTFR_A, the spatial sound transfer characteristic Hrs_A, and the spatial sound transfer The characteristic Hlo_A is associated with each other to form one data set.

The first to third ear canal transmission characteristics are second preset data. The comparison unit 302 of the server device 300 determines the correlation between the user data and the preset data for each of the first to third external auditory canal transmission characteristics. That is, the comparison unit 302 determines the correlation between the user data and the preset data regarding the first external auditory canal transmission characteristic. Similarly, the comparison unit 302 determines the correlation between the user data and the preset data for each of the second and third external auditory canal transmission characteristics.

Comparison unit 302 obtains a similarity score based on the three correlations. The similarity score can be, for example, a simple average or a weighted average of the first to third correlations. The extraction unit 304 extracts the first preset data of the dataset with the highest similarity score. By performing matching using three or more ear canal transmission characteristics, preset data suitable for the user can be extracted. Extra-head localization filters can be determined with higher accuracy. Furthermore, for the ear canal transmission characteristics that are not used for matching, the weight of the weighted addition may be set to 0.

Note that in the above description, the position of the driver 45 within the housing 46 is variable, but a housing having three drivers 45 may also be used. Alternatively, a mechanism that can adjust the position and angle of the housing 46 may be provided. That is, by adjusting the angle of the housing 46 with respect to the headphone band 43B, the relative position of the driver 45 with respect to the microphones 2L and 2R may be changed.

Embodiment 3.
In this embodiment, shape data corresponding to the shape of the head of the user and the subject is used. Specifically, the headphones 43 are provided with a sensor for acquiring shape data according to the shape of the head. A specific example of the sensor provided in the headphones 43 will be described below.

(Sensor example 1)
FIG. 12 is a front view schematically showing the headphones 43 having the opening sensor 141. An opening sensor 141 is provided on the headphone band 43B. The opening sensor 141 detects the amount of deformation of the headphone band 43B, that is, the opening of the headphones 43. As the opening sensor 141, an angle sensor that detects the opening angle of the headphone band 43B can be used. Alternatively, a gyro sensor or a piezoelectric sensor may be used as the opening sensor 141. The opening sensor 141 detects the width W of the head.

FIG. 13 is a front view schematically showing subjects 1 having different head widths. For the person to be measured 1 having a narrow width W1, the degree of opening is small, and for the person to be measured 1 having a wide width W2, the degree of opening is large. Therefore, the opening detected by the opening sensor 141 corresponds to the width W of the head. That is, the opening sensor 141 acquires the width of the head as shape data by detecting the opening angle of the headphones 43.

(Sensor example 2)
FIG. 14 is a front view schematically showing the headphones 43 having the slide position sensor 142. A slide mechanism 146 is provided between the headphone band 43B and the left unit 43L. A slide mechanism 146 is provided between the headphone band 43B and the right unit 43R. The slide mechanism 146 slides the left unit 43L and the right unit 43R up and down with respect to the headphone band 43B, as shown by solid arrows in FIG. 14. Thereby, the height H from the top of the head of the person to be measured 1 to the left unit 43L and right unit 43R can be changed. The slide position sensor 142 detects the slide position (slide length) of the slide mechanism 146. The slide position sensor 142 is, for example, a rotation sensor, and detects the slide position based on the rotation angle.

The sliding position of the sliding mechanism 146 changes depending on the length of the head. FIG. 15 shows subjects 1 having different head lengths. Here, the heights from the top of the head to the external ear hole are shown as H1 and H2. The slide position changes depending on the heights H1 and H2 from the top of the head to the external ear hole. Therefore, when the slide position sensor 142 detects the slide position of the slide mechanism 146, the length of the head can be detected as shape data.

(Sensor example 3)
FIG. 16 is a top view schematically showing headphones 43 having a swivel angle sensor 143. A swivel angle sensor 143 is provided between the headphone band 43B and the left unit 43L. A swivel angle sensor 143 is provided between the headphone band 43B and the right unit 43R. The swivel angle sensor 143 detects the swivel angles of the left unit 43L and right unit 43R of the headphones 43, respectively. The swivel angle is an angle around the vertical axis of the left unit 43L or right unit 43R with respect to the headphone band 43B (in the direction of the arrow in FIG. 16).

FIG. 17 is a top view schematically showing different swivel angles. For example, in the case of the person to be measured 1 whose ears are located behind the center of the head, the left unit 43L or the right unit 43R is opened forward (upper row of FIG. 17). Alternatively, in the case of the person to be measured 1 whose forehead is wide and whose back is narrow, the left unit 43L or right unit 43R will be in a state opened forward. In the case of the person to be measured 1 whose ears are located in front of the center of the head, the left unit 43L or the right unit 43R is in a rearward open state (lower part of FIG. 17). In the case of the subject 1 who has a narrow forehead and a wide back head, the left unit 43L or right unit 43R is in a state opened forward.

(Sensor example 4)
FIG. 18 is a front view schematically showing the headphones 43 having the hanger angle sensor 144. A hanger angle sensor 144 is provided between the headphone band 43B and the left unit 43L. A hanger angle sensor 144 is provided between the headphone band 43B and the right unit 43R. The hanger angle sensor 144 detects the hanger angles of the left unit 43L and right unit 43R of the headphones 43, respectively. The hanger angle is an angle around the front-rear axis of the left unit 43L or right unit 43R with respect to the headphone band 43B (in the direction of the arrow in FIG. 18).

FIG. 19 is a top view schematically showing different hanger angles. For example, in the case of the person to be measured 1 whose ears are placed upward, the left unit 43L or right unit 43R is in a downwardly open state (upper row of FIG. 19). Further, in the case of the subject 1 having a narrow face, the left unit 43L or the right unit 43R will be in an upwardly open state. When the ears are at the bottom, the left unit 43L or the right unit 43R is in an upwardly open state (lower part of FIG. 19). Further, in the case of the subject 1 having a wide face, the left unit 43L or the right unit 43R will be in a downwardly open state.

By using at least one of the opening sensor 141, the slide position sensor 142, the swivel angle sensor 143, and the hanger angle sensor 144, shape data according to the head shape of the person to be measured 1 can be detected. The shape data may be expressed as a relative position or relative angle between the left unit 43L and the right unit 43R. The shape data may be data indicating the dimensions of the actual head shape.

Of course, the above sensor is just an example, and other sensors may be provided in the headphones 43 to detect the shape data. One or more types of shape data may be detected for one ear, but two or more types may be combined. When two or more types of shape data are detected for one ear, the shape data may be multidimensional vector data.

Various sensors detect shape data for each ear of the person to be measured 1. Various sensors also detect shape data about the user. A data storage unit 303 of the server device 300 stores shape data. As shown in FIG. 20, the shape data is associated with the first and second presets.

The comparison unit 302 performs matching using shape data. For example, if the difference in shape data between the user and the subject is greater than a threshold, that data set may be excluded from matching. In other words, the similarity score may be calculated based on the comparison result of the shape data. In this embodiment, server device 300 extracts first preset data based on the shape data. Thereby, a more appropriate extra-head localization filter can be determined.

Embodiment 4.
As shown in Embodiment 1, it is preferable to make the incident angles of measurement signals the same in the first preliminary measurement, the second preliminary measurement, and the user measurement. On the other hand, the state in which the headphones 43 are worn differs depending on the shape of the head of the person to be measured 1 and the like. For example, the mounting angle of the housing 46 changes depending on the shape of the head of the person 1 to be measured. Therefore, in the fourth embodiment and the second modification thereof, a headphone 43 that can adjust the incident angle of the measurement signal will be described. Embodiment 4 and its second modification may be used for at least one of the second preliminary measurement and the user measurement.

FIG. 21 is a top view schematically showing the configuration of the headphones 43. FIG. 22 is a diagram showing a configuration in which the driver 45 is in the first to third positions. In FIG. 22, the driver 45 in the first position is shown as a driver 45f, the driver 45 in the second position is shown as a driver 45m, and the driver 45 in the third position is shown as a driver 45b.

Headphones 43 have a swivel angle sensor 143. The swivel angle sensor 143 detects the swivel angle of the housing 46 as described above. The left unit 43L includes a driver 45, a housing 46, a guide mechanism 47, and a drive motor 48. The right unit 43R includes a driver 45, a housing 46, a guide mechanism 47, and a drive motor 48. Since the left unit 43L and the right unit 43R have a symmetrical configuration, a description of the right unit 43R will be omitted as appropriate.

A driver 45, a guide mechanism 47, and a drive motor 48 are provided within the housing 46. The drive motor 48 is an actuator such as a stepping motor or a servo motor, and moves the driver 45. A guide mechanism 47 is fixed to the housing 46. The guide mechanism 47 is a guide rail formed in an arc shape when viewed from above. Note that the guide mechanism 47 is not limited to a circular arc shape. For example, the guide mechanism 47 may have an elliptical shape or a hyperbolic shape.

A driver 45 is attached to the housing 46 via a guide mechanism 47. Drive motor 48 moves driver 45 along guide mechanism 47 . By using the arc-shaped guide mechanism 47, measurements can be performed at any position with the driver 45 facing the external ear canal.

Further, the drive motor 48 has a sensor that detects the amount of movement of the driver 45. As the sensor, for example, a motor encoder that detects the motor rotation angle can be used. Thereby, the position of the driver 45 within the housing 46 can be detected. That is, the position of the driver 45 in the guide mechanism 47 is detected. Further, a swivel angle sensor 143 is provided between the housing 46 and the headphone band 43B. Thereby, the swivel angle of the housing 46 with respect to the headphone band 43B can be detected.

Based on the amount of movement of the driver 45 and the swivel angle, the direction of the driver 45 relative to the microphone 2L or the external ear canal can be determined. In other words, the angle of incidence of the measurement signal output from the driver 45 can be determined. Even if the wearing angle of the headphones 43 changes depending on the shape of the user's head, etc., the incident angles of the measurement signals in the second preliminary measurement and the user measurement can be made the same. Furthermore, the incident angles of the measurement signals in the second preliminary measurement and the first preliminary measurement can be made the same. That is, the drive motor 48 moves the driver 45 to an appropriate position based on the swivel angle. This enables more appropriate matching.

Modification example 2.
Modification 2 of Embodiment 4 will be described using FIGS. 23 and 24. FIG. 23 is a top view schematically showing headphones 43 of Modification 2. FIG. 24 is a diagram showing a state in which the headphones 43 are worn. Also in the second modification, the left unit 43L and the right unit 43R have a symmetrical configuration, so the description of the right unit 43R will be omitted as appropriate.

The left unit 43L includes a driver 45f, a driver 45m, a driver 45b, a housing 46, and an outer housing 49. In the second modification, three drivers 45f, 45m, and 45b are housed in the housing 46. Of course, the number of drivers is not limited to three, but may be two or more. Furthermore, an outer housing 49 is provided outside the housing 46. That is, the housing 46 becomes an inner housing housed inside the outer housing 49.

A driver 45f, a driver 45m, and a driver 45b are fixed to the housing 46. In Modification 2, the positions of driver 45f, driver 45m, and driver 45b with respect to housing 46 are not variable. Further, the housing 46 is fixed to the headphone band 43B. That is, the swivel angle of the housing 46 with respect to the headphone band 43B does not change.

The angle of the outer housing 49 with respect to the housing 46 is variable. For example, the housing 46 and the outer housing 49 are connected by a bellows-shaped boot (not shown). Further, the housing 46 and the outer housing 49 may be sealed with a bellows-shaped boot.

As shown in FIG. 24, the angle of the outer housing 49 changes depending on the shape of the head of the person to be measured 1. In FIG. 24, the front and back positions of the left ear 9L and right ear 9R are different. In the subject 1 whose left ear 9L and right ear 9R are in standard positions, the left and right outer housings 49 are directly facing each other (upper row of FIG. 24).

For the person to be measured 1 whose left ear 9L and right ear 9R are located on the rear side, the left and right outer housings 49 are in a rearward open state (middle row in FIG. 24). In other words, the front ends of the left and right outer housings 49 are close to each other, and the rear ends are apart.

In the subject 1 whose left ear 9L and right ear 9R are located on the front side, the left and right outer housings 49 are in a state opened forward (lower part of FIG. 24). In other words, the rear ends of the left and right outer housings 49 are close to each other, and the front ends are separated.

By changing the angle of the outer housing 49 in this way, it is possible to improve the mounting condition. For example, the left unit 43L and right unit 43R can be placed in close contact with the person to be measured 1. Measurement can be performed with no gap between the person to be measured 1 and the left unit 43L. Therefore, it is possible to prevent the headphones 43 from shifting during measurement. Moreover, since the outer housing 49 can seal the measurement space in which the second preliminary measurement or user measurement is performed, that is, the space around the external ear canal, more accurate measurement can be performed.

The position of the driver in the housing 46 is fixed, and the swivel angle of the housing 46 is fixed. Therefore, regardless of the shape of the head of the person to be measured 1, the left and right housings 46 face each other directly. This makes it possible to suppress changes in the angle of incidence of the measurement signal. Therefore, measurement can be performed at a predetermined angle of incidence, and measurement can be performed with higher accuracy.

By using the headphones 43 of the fourth embodiment or its second modification, the first and second external auditory canal transmission characteristics can be measured. Based on the first ear canal transfer characteristic, a spatial acoustic filter is generated according to the spatial acoustic transfer characteristic from the sound source to the ear. Based on the second ear canal transmission characteristic, an inverse filter is generated that cancels the headphone characteristic. Therefore, more accurate extra-head localization processing can be performed.

(Example of arrangement of driver 45f)
An example of the arrangement of the driver 45f will be explained using FIG. 5 and FIG. 25. Since the arrangement of the driver 45f and the stereo speaker 5 is symmetrical, the arrangement of the left speaker 5L and the driver 45f of the left unit 43L will be described below.

In FIG. 5, the direction from the head center O to the left speaker 5L is parallel to the direction from the microphone 2L to the driver 45f. Generally, the stereo speakers 5 are preferably arranged so that the center of the head O, the left speaker 5L, and the right speaker 5R form an equilateral triangle. For this reason, the opening angle θ from the head center O to the left speaker 5L or right speaker 5R is set to 30°.

When considering how the wavefront of a sound wave propagates, if it is approximated as a plane sound wave, a wavefront perpendicular to the straight line connecting the left speaker 5L and the head center O will be propagated. Since it is a plane wave, the left speaker 5L and the head center O are parallel, and the left speaker 5L and the left ear 9L are parallel, and similarly, the driver 45f and the left ear 9L are parallel. Therefore, it is preferable to arrange the driver 45f as shown in FIG.

On the other hand, assuming that it is a spherical sound wave, it is preferable to arrange the stereo speakers 5 and the driver 45f as shown in FIG. 25. In FIG. 25, the driver 45f is arranged on a straight line from the microphone 2L to the speaker 5L. Of course, the speaker 5L may be placed toward the left ear 9L. The arrangement from the microphone 2L to the speaker 5L is not limited to the arrangement shown in FIGS. 5 and 25. The direction from the left microphone 2L to the driver 45f may be along the direction from the person to be measured 1 to the speaker 5L serving as the sound source. Here, the position of the person to be measured 1 may be the center of the head O, or may be the position of the left microphone 2L.

The first to fourth embodiments and their modifications described above can be combined as appropriate. Furthermore, the order in which the first to third external auditory canal transmission characteristics are measured is not particularly limited. For example, the second ear canal transmission characteristic may be measured first.

Some or all of the above processes may be executed by a computer program. The programs described above can be stored and provided to a computer using various types of non-transitory computer readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R/W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be provided to the computer on various types of transitory computer readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can provide the program to the computer via wired communication channels, such as electrical wires and fiber optics, or wireless communication channels.

Although the invention made by the present inventor has been specifically explained based on the embodiments above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof. Needless to say.

U User 1 Subject 2L Left microphone 2R Right microphone 5L Left speaker 5R Right speaker 9L Left ear 9R Right ear 10 Extra-head localization processing unit 11 Convolution calculation unit 12 Convolution calculation unit 21 Convolution calculation unit 22 Convolution calculation unit 24 Adder 25 Adder 41 Filter section 42 Filter section 43 Headphones 45 Driver 45f Driver 45m Driver 45b Driver 46 Housing 47 Guide mechanism 48 Drive motor 49 Outer housing 100 Extra-head localization processing device 111 Impulse response measurement section 112 ECTF characteristic acquisition section 113 Transmission section 114 Reception Units 120 Arithmetic processing unit 121 Inverse filter calculation unit 122 Filter storage unit 200 Measuring device 201 Measurement processing device 300 Server device 301 Receiving unit 302 Comparing unit 303 Data storage unit 304 Extracting unit 305 Transmitting unit

Claims (5)

headphone band,
left and right housings provided on the headphone band;
a guide mechanism provided in the left and right housings, respectively;
drivers arranged in the left and right housings, respectively;
an actuator that moves the driver along the guide mechanism ;
a swivel angle sensor that detects a swivel angle of the housing with respect to the headphone band;
Headphones comprising : a sensor that detects the amount of movement of the driver by the actuator . headphone band,
left and right inner housings fixed to the headphone band;
a plurality of drivers each fixed to the left and right inner housings and outputting signals at different timings ;
A headphone comprising: an outer housing that is arranged on the outside of the left and right inner housings, and whose angle with respect to the inner housing is variable. A headphone band, left and right housings provided on the headphone band, guide mechanisms provided in the left and right housings, drivers respectively disposed in the left and right housings, and a driver along the guide mechanism. an actuator for moving the headphones; and a microphone unit that outputs a measurement signal to a pair of headphones that is attached to the user's ear and has a microphone that picks up the sound output from the driver of the headphone. An outside-of-head localization filter determination device comprising: a measurement processing unit that acquires a sound pickup signal and measures an external auditory canal transfer characteristic;
measuring a first ear canal transmission characteristic from the driver at a first position to the microphone;
measuring a second ear canal transmission characteristic from the driver at a second position to the microphone;
generating a spatial acoustic filter according to a spatial acoustic transmission characteristic from the sound source to the ear based on the first ear canal transmission characteristic;
An extra-head localization filter determining device that generates an inverse filter that cancels the characteristics of the headphones based on the second ear canal transfer characteristics. A headphone band, left and right housings provided on the headphone band, guide mechanisms provided in the left and right housings, drivers respectively disposed in the left and right housings, and a driver along the guide mechanism. an actuator for moving the headphones;
A method for determining an outside-of-head localization filter using a microphone unit that is attached to a user's ear and has a microphone that picks up sound output from the driver of the headphone, the method comprising:
outputting a measurement signal from the driver located at a first position and collecting a sound signal with the microphone, thereby measuring a first ear canal transfer characteristic from the first position to the microphone; ,
outputting a measurement signal from the driver at the second position and collecting the sound signal with the microphone, thereby measuring a second ear canal transfer characteristic from the second position to the microphone; ,
generating a spatial acoustic filter according to a spatial acoustic transmission characteristic from a sound source to the ear based on the first ear canal transmission characteristic;
A method for determining an extra-head localization filter, including the step of generating an inverse filter that cancels characteristics of the headphones based on the second ear canal transfer characteristics. a headphone band, left and right inner housings fixed to the headphone band, a plurality of drivers fixed to the left and right inner housings, and a plurality of drivers arranged outside the left and right inner housings, each having an angle with respect to the inner housing. a variable outer housing, and outputs a measurement signal from a microphone unit having a microphone that is worn on a user's ear and picks up sound output from the driver of the headphone. An outside-of-head localization filter determination device comprising: a measurement processing unit that acquires a sound pickup signal and measures an external auditory canal transfer characteristic;
measuring a first ear canal transmission characteristic from the driver at a first position to the microphone;
measuring a second ear canal transmission characteristic from the driver at a second position to the microphone;
generating a spatial acoustic filter according to a spatial acoustic transmission characteristic from the sound source to the ear based on the first ear canal transmission characteristic;
a reverse filter that cancels the characteristics of the headphones based on the second ear canal transmission characteristics;
Extra-head localization filter determining device that generates filters.

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