JP2013219444A - Audio processing device and image pickup device - Google Patents

Abstract

【Task】
Make it possible to easily adjust the sensitivity change of the stereo microphone after starting use.
[Solution]
After adjusting the sensitivity of the R microphone (12R) and the L microphone (12L) at the time of shipment, a reference sound of a plurality of frequencies is generated from the speaker (40), and the R sound level and the L sound level with respect to the reference sound are used as the reference sound level. Store in the storage unit (28a). In the sensitivity adjustment mode after the start of use, the control device (22) acquires the environmental sound, checks the frequency of the low sound level, generates the reference sound of the frequency from the speaker (40), and the filtering processing device (18R, In 18L), a filtering coefficient for cutting other frequencies is set. The level sounding device (28R, 28L) measures the output sound level of the device (18R, 18L), compares it with the reference sound level, and corrects the filtering coefficient so that the difference becomes small.
[Selection] Figure 1

Description

  The present invention relates to an audio processing device and an imaging device, and more specifically to an audio processing device that adjusts the sensitivity of a stereo audio input device, and an imaging device including such an audio processing device.

  In order to record stereo sound with a stereo recording device, it is necessary to have two microphones with the same sensitivity. However, individual variations in microphone sensitivity occur due to factors such as component variations and assembly variations. To prepare microphones with the same sensitivity, it is necessary to select microphones for each sensitivity, which is not practical.

  For this reason, it is common to provide sound processing for adjusting the sound level of the sound signal input by each microphone (Patent Document 1). For example, an audio level adjustment circuit is connected to the output of one or both of the two left and right microphones, and adjustment audio is generated from a sound source that is equidistant from both microphones. The adjustment value of one or both of the sound level adjustment circuits is determined so that the sound level of the input sound signal after the sound level adjustment by both microphones becomes equal to the sound for adjustment.

  Further, in Patent Document 2, an adjustment sound corresponding to a predetermined reference sound pressure value (default value) is generated from a speaker, and an output sound signal of each microphone corresponding to the adjustment sound corresponds to the reference sound pressure value. It is described that the sound level is adjusted to be adjusted.

JP 2008-060625 A JP 2006-174216 A

  In the prior art, it is necessary to install the speakers that generate the adjustment sound at equal distances from the two microphones constituting the stereo microphone, and there are restrictions on the adjustment location.

  In order to calibrate the sound level so that the measured sound level matches the reference sound pressure value, make sure that there is no sound in the same frequency band as the sound frequency emitted by the sound source for adjustment in the calibration environment. There must be. This is because accurate calibration cannot be performed under the influence of ambient sounds.

  Since the sensitivity of the microphone itself changes with time, it is necessary to further adjust the audio level adjustment value in response to such a change.

  In general, a stereo microphone is adjusted so that the left and right audio outputs are uniform when recording from the left and right microphones using a reference sound source during manufacture. However, it is difficult to secure a reference sound source that is equidistant from the left and right microphones and that can cover a wide frequency range in the sensitivity adjustment for the secular change after the start of use. Such a problem can occur not only in a stereo microphone but also in a system using a plurality of microphones.

  An object of the present invention is to provide an audio processing device that can easily adjust or calibrate a difference in microphone sensitivity not only during installation but also during operation, and an imaging device including such an audio processing device.

  The speech processing apparatus according to the present invention is a speech processing apparatus that adjusts the sensitivity of each speech input from a plurality of speech input means, and a plurality of filtering processing means that respectively filter input speech of the plurality of speech input means; A plurality of spectrum measuring means for measuring the level of the input voice of the plurality of voice input means for a plurality of frequencies, a plurality of level measuring means for measuring the levels of the output voice signals of the plurality of filtering processing means, In response to an instruction to start sensitivity correction, a plurality of level adjusting means for adjusting the levels of the output audio signals of the plurality of filtering processing means, a sound generating means, and a low sound level among ambient sounds by the spectrum measuring means Causing the sound generating means to generate a reference sound of the sound frequency for adjustment corresponding to the frequency, and the adjustment Control means for setting a filtering coefficient in the filtering processing means so as to cut other than the audio frequency, and correcting the filtering coefficient in accordance with a difference between an output sound level of the filtering processing means and a reference sound level. And

  According to the present invention, the sensitivity of the voice input means can be adjusted to the initial state or a state close thereto by generating a reference sound of a predetermined frequency from the equipped sound generation means. You can easily restore the mutual balance.

It is a schematic block diagram of one Example of this invention. It is an external view of the imaging device incorporating the present embodiment. It is an operation | movement flowchart of the sensitivity adjustment of a present Example. It is a detailed flowchart of the audio | voice level correction process of the flow shown in FIG. It is an example of the spectrum of ambient sound. It is an example of a spectrum of R channel sound at the time of generating a reference sound. It is an example of a spectrum of L channel sound at the time of generating a reference sound. It is another operation | movement flowchart of the sensitivity adjustment of a present Example. It is another operation | movement flowchart of the sensitivity adjustment of a present Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic block diagram of an embodiment of a speech processing apparatus according to the present invention. First, the basic configuration and operation will be described.

  The right channel microphone (R microphone) 12R and the left channel microphone (L microphone) 12L constitute a stereo microphone. The audio processing apparatus 10 includes an R channel processing system that processes an output audio signal of the R microphone 12R and an L channel processing system that processes an output audio signal of the L microphone 12L.

  The R channel processing system will be described. The input audio signal from the R microphone 12R is amplified by the amplifier 14R, converted into a digital signal by the A / D converter 16R, and input to the filtering processing device 18R and the spectrum measuring device 20R. The spectrum measuring device 20R measures the frequency spectrum of the output voice data of the A / D converter 16R and notifies the control device 22 of the measurement result. More specifically, the spectrum measurement apparatus 20R measures (detects) one or more frequencies or frequency bands that are not included in the surrounding environmental sound in the output sound data of the A / D converter 16R. This spectrum measurement result is used for sensitivity adjustment of the R microphone 12R.

  The filtering processing device 18R performs a filtering process on the output audio data of the A / D converter 16R according to the filtering coefficient set by the control device 22. Detailed operations of the filtering processing device 18R and the spectrum measuring device 20R will be described later.

  The audio data filtered by the filtering processing device 18R is input to the level adjusting device 24R and the level measuring device 26R. The level measuring device 26R measures the sound level of the output sound data of the filtering processing device 18R at a specific frequency or frequency band, and notifies the control device 22 of the measurement result. Although details will be described later, the control device 22 adjusts the gain of the level adjusting device 24R according to the sound level from the level measuring device 26R. The high pass filter (HPF) 30R extracts a high frequency component suitable for audio recording from the output audio data of the level adjusting device 24R, and supplies the high frequency component to the audio recording / reproducing device 32.

  The operation of the L channel processing system is basically the same as that of the R channel processing system. That is, the input audio signal from the L microphone 12L is amplified by the amplifier 14L, converted into a digital signal by the A / D converter 16L, and input to the filtering processing device 18L and the spectrum measuring device 20L. The spectrum measuring device 20L measures the frequency spectrum of the output voice data of the A / D converter 16L and notifies the control device 22 of the measurement result. More specifically, the spectrum measuring apparatus 20L measures (detects) one or more frequencies or frequency bands that are not included in the surrounding environmental sound in the output sound data of the A / D converter 16R. The frequency or frequency band to be measured is the same as that of the spectrum measuring apparatus 20R. This spectrum measurement is used for sensitivity adjustment of the L microphone 12L. In the case of adopting a simple method of adjusting the sensitivity of the L microphone 12L based on the measurement result of the spectrum measurement device 20R, either the spectrum measurement device 20L or the spectrum measurement device 20R can be omitted.

  The filtering processing device 18L performs a filtering process on the output audio data of the A / D converter 16L according to the filtering coefficient set by the control device 22. Detailed operations of the filtering processing device 18L and the spectrum measuring device 20L will be described later.

  The audio data filtered by the filtering processing device 18L is input to the level adjusting device 24L and the level measuring device 26L. The level measurement device 26L measures the sound level of the output sound data of the filtering processing device 18L at a specific frequency or frequency band, and notifies the control device 22 of the measurement result. Although details will be described later, the control device 22 adjusts the gain of the level adjusting device 24L according to the sound level from the level measuring device 26L. The HPF 30L extracts a high frequency component suitable for audio recording from the output audio data of the level adjusting device 24L, and supplies the high frequency component to the audio recording / reproducing device 32.

  The audio recording / reproducing device 32 processes the R channel audio data from the HPF 30R and the L channel audio data from the HPF 30L for recording, and records them on the recording medium 34. The recording medium 34 is composed of, for example, a nonvolatile semiconductor memory or a hard disk device.

  The control device 22 includes a CPU, a RAM, a ROM, and the like, and includes a calculation unit 22a and a sensitivity adjustment frequency determination unit 22b as functions. The storage device 28 includes a reference audio level storage unit 28a, a filtering coefficient storage unit 28b, and a sensitivity adjustment audio data storage unit 28c. The reference sound level storage unit 28a stores a reference sound pressure value (default value) that serves as a reference when adjusting the sensitivity of the R microphone 12R and the L microphone 12L for each predetermined frequency. The filtering coefficient storage unit 28b stores filtering coefficients to be set in the filtering processing devices 18R and 18L. The sensitivity adjustment audio data storage unit 28c stores in advance audio data of each frequency to be measured by the spectrum measuring apparatuses 20R and 20L.

  The control device 22 displays an operation state, an operation menu, and the like on the display device 42. The user can instruct the controller 22 to perform various specific operations using the operation device 44 including various operation buttons. In the present embodiment, the sensitivity adjustment mode can be set to the control device 22 by the operation device 44 in addition to the recording / reproducing of the sound.

  In the reproduction mode, the audio recording / reproducing device 32 reproduces recorded audio data from the recording medium 34 and supplies it to the D / A converter 36. On the other hand, in the sensitivity adjustment mode in which the sensitivity of the R channel and the L channel is adjusted, the sensitivity adjustment audio data stored in the sensitivity adjustment audio data storage unit 28 c of the storage device 28 is read out to the D / A converter 36. The D / A converter 36 converts the input audio data into an analog signal. The amplifier 38 amplifies the analog audio signal from the D / A converter 36 and applies it to the speaker 40. The speaker 40 acoustically outputs an analog audio signal from the amplifier 38. The speaker 40 outputs a reproduction sound of the audio data recorded on the recording medium 34 in the reproduction mode, and outputs a reference sound for sensitivity adjustment in the sensitivity adjustment mode.

  FIG. 2 shows an external view of the imaging apparatus incorporating the embodiment shown in FIG. An R microphone 12R and an L microphone 12L are arranged in an imaging apparatus that is a digital single-lens reflex camera, and a speaker 40 is arranged on the left side surface. The speaker 40 is at an unequal distance from the R microphone 12R and the L microphone 12L. The display device 42 is disposed on the back surface of the imaging device. The imaging apparatus illustrated in FIG. 2 can capture a moving image in addition to a still image.

  The operation in the sensitivity adjustment mode in this embodiment will be described. FIG. 3 shows an operational flowchart of sensitivity adjustment. The control device 22 controls each unit according to the flow shown in FIG. The sensitivity adjustment in the present embodiment includes an initial sound level measurement process or procedure for storing the acquired sound level in advance after the factory sensitivity adjustment, and a sensitivity adjustment process or procedure for actually adjusting the sensitivity after the start of use. The sensitivity adjustment process or procedure after the start of use is determined by determining the correction value based on the pre-processing or procedure for determining the adjustment audio frequency, the measurement process or procedure for measuring the acquired sound level of the reference sound, and the measurement result. It consists of a process or procedure set in the adjustment device.

  As the initial sound level measurement process, the control device 22 executes the following process. That is, immediately after adjusting the sensitivities of the R microphone 12R and the L microphone 12L at the time of manufacture or shipment, reference sounds of a plurality of frequencies are generated simultaneously or sequentially from the speaker 40. Then, the sound levels of the R channel and the L channel with respect to the reference sound are measured by the level measuring devices 26R and 26L, and the control device 22 stores the measured sound level as the reference sound level in the reference sound level storage unit 28a.

  First, the control device 22 waits for the user to instruct the start of sensitivity correction with the operation device 44 (S101). In response to the sensitivity correction start instruction, the control unit 22 resets the correction number counter to zero (S102), and acquires ambient environmental sound by the R microphone 12R and the L microphone 12L (S103). As described above, the audio signals output from the R microphone 12R and the L microphone 12L are input to the spectrum measuring apparatuses 20R and 20L via the amplifiers 14R and 14L and the A / D converters 16R and 16L, respectively.

  The control device 22 causes the spectrum measuring devices 20R and 20L to measure the spectrum of the environmental sound (S104). That is, the spectrum measuring devices 20R and 20L measure the sound levels of a plurality of predetermined frequencies for the R sound data and the L sound data from the A / D converters 16R and 16L, respectively. For example, the spectrum measuring apparatuses 20R and 20L measure the sound level in increments of 500 Hz between 500 Hz and 10 kHz. The sensitivity adjustment audio data storage unit 28c of the storage device 28 stores in advance audio data in increments of 500 Hz between the frequencies to be measured by the spectrum measuring apparatuses 20R and 20L, that is, between 500 Hz and 10 kHz. .

  The sensitivity adjustment frequency determination unit 22b determines the frequency with the lowest measurement sound level of the spectrum measurement devices 20R and 20L as the adjustment sound frequency used for microphone sensitivity adjustment (S105). A frequency at which the measurement sound level of the spectrum measurement devices 20R and 20L is smaller than a predetermined threshold may be determined as an adjustment sound frequency used for microphone sensitivity adjustment. The sensitivity adjustment frequency determination unit 22b stores the determined adjustment audio frequency in the filtering coefficient storage unit 28b.

  The control device 22 sets filtering coefficients for cutting other than the adjustment audio frequency in the filtering processing devices 18R and 18L (S106). This is the preprocessing for determining the adjustment audio frequency as the premise of sensitivity adjustment.

  The control device 22 causes the speaker 40 to output the sensitivity adjustment sound having the adjustment sound frequency determined in step S105 for a predetermined time (S107). Specifically, the control device 22 reads the sensitivity adjustment audio data of the adjustment audio frequency determined in step S105 from the sensitivity adjustment audio data storage unit 28c of the storage device 28 to the D / A converter 36. As described above, the D / A converter 36 converts the sensitivity adjustment audio data read from the sensitivity adjustment audio data storage unit 28c into an analog signal. The amplifier 38 amplifies the analog audio signal from the D / A converter 36 and applies it to the speaker 40. The speaker 40 acoustically outputs the sensitivity adjustment sound indicated by the analog sound signal from the amplifier 38.

  The R microphone 12R and the L microphone 12L take in ambient sound including sensitivity adjustment sound from the speaker 40, and output a corresponding sound signal (S108). Output audio signals from the R microphone 12R and the L microphone 12L are input to the filtering processing devices 18R and 18L via the amplifiers 14R and 14L and the A / D converters 16R and 16L, respectively. The filtering processing devices 18R and 18L respectively filter the audio data from the A / D converters 16R and 16L according to the filtering coefficient set in step S106. That is, the filtering processing devices 18R and 18L separate and extract the adjustment audio frequency component from the audio data from the A / D converters 16R and 16L.

  The control device 22 causes the level measuring devices 26R and 26L to measure the sound levels of the output sound signals of the filtering processing devices 18R and 18L, respectively (S109). The computing unit 22a of the control device 22 compares the audio level measured by the level measuring devices 26R and 26L with the reference audio level corresponding to the adjustment audio frequency stored in the reference audio level storage unit 28a, and the difference between them. Is output (S110).

The control device 22 determines whether or not the difference between the sound levels calculated in S110 is within a predetermined threshold (S111). When the difference is within the predetermined threshold (S111), the control device 22 ends the sensitivity correction operation (S115). On the other hand, if the difference is outside a predetermined threshold (S 111), the control device 22, after incrementing the correction number counter N (S112), the correction number counter N is determined whether it exceeds a predetermined number N ₀ (S113). When the correction number counter N exceeds the predetermined number N ₀ (S113), the control device 22 ends the sensitivity correction operation with the correction impossible (S115).

When the correction number counter N is equal to or smaller than the predetermined number N ₀ (S113), the control device 22 corrects the sound level by a method described later so that the sound level is within the threshold value (S114). After the sound level correction (S114), the control device 22 executes step S107 and subsequent steps again.

  FIG. 4 shows a detailed operation flowchart of the sound level correction operation (S114). The control device 22 reads out the filtering coefficient information being applied from the filtering coefficient storage unit 28b (S201).

  The computing unit 22a calculates a filtering coefficient for correcting the difference for the R sound and the L sound from the difference value calculated in S110 and the filtering coefficient information being applied read in S201 (S202).

  The control unit 22 stores the filtering coefficient calculated in S202 in the filtering coefficient storage unit 28b without being overwritten or overwritten (S203), and applies the filtering coefficient to the filtering processing devices 18R and 18L (S204). Thereby, the sensitivity of the R channel and the L channel is corrected.

  A method for determining the reference audio level will be described. Even if the microphone sensitivity is set appropriately at the time of manufacture, it may deteriorate over time. In the case of using a plurality of microphones, it is further necessary to maintain the relationship between their sensitivities to the same level as the initial state. As described above, a reference sound source for sensitivity adjustment can be prepared at the time of manufacture, but it is difficult to prepare a sound source suitable for sensitivity adjustment after the user starts using it. In the present embodiment, this problem is solved by the method described below using the speaker 40 that can be used even after the user starts use.

  When the product is shipped, the sensitivities of the R microphone 12R and the L microphone 12L are adjusted appropriately. At this time, the output sound of the speaker 40 is captured by the R microphone 12R and the L microphone 12L, and the sound levels are measured by the level measuring devices 26R and 26L, respectively, and stored in the reference sound level storage unit 28a. Thereby, although the speaker 40 is not positioned in front of the R microphone 12R and the L microphone 12L, the sensitivity reference value or sensitivity difference of the R microphone 12R and the L microphone 12L depending on the distance and direction to the speaker 40 is measured and stored. it can.

  FIG. 5 shows a spectrum of ambient sound at the stage where the sensitivity of the R microphone 12R and the L microphone 12L is adjusted before shipment. 6 and 7 show spectrum examples of output audio signals of the R microphone 12R and the L microphone 12L when a reference sound is generated from the speaker 40 in the situation shown in FIG. 5 to 7, the horizontal axis indicates the frequency, and the vertical axis indicates the sound level (sound pressure level). In the examples shown in FIGS. 6 and 7, the reference sounds of 1 kHz, 2 kHz, and 4 kHz are generated simultaneously, but actually, the reference sounds of the respective frequencies are generated individually.

  The example shown in FIGS. 6 and 7 is as follows. That is, with respect to the reference sound of 1 kHz, the sound level of the output sound signal of the R microphone 12R is −28.0 dB as indicated by reference numeral 204, whereas the sound level of the output sound signal of the L microphone 12L is denoted by reference numeral 207. As shown in the figure, it was −24.0 dB. The sound level of the output sound signal of the R microphone 12R is −28.0 dB as indicated by reference numeral 205 with respect to the 2 kHz reference sound, whereas the sound level of the output sound signal of the L microphone 12L is indicated by reference numeral 208. Thus, it was −24.0 dB. The sound level of the output sound signal of the R microphone 12R is −28.1 dB as indicated by reference numeral 206 with respect to the reference sound of 4 kHz, whereas the sound level of the output sound signal of the L microphone 12L is indicated by reference numeral 209. Thus, it was −24.1 dB.

  Thus, it can be seen that the output sound level of the R microphone 12R is about −28 dB on average and that of the L microphone 12L is about −24 dB with respect to the output sound of the speaker 40. That is, there is a difference of about −4 dB between the R microphone 12R and the L microphone 12L, and it can be seen that the R microphone 12R has a lower sound pressure of about −4 dB than the L microphone 12L.

  The control device 22 uses the sound level obtained by this measurement (−28 dB for the R microphone 12R, −24 dB for the L microphone 12L) as a reference sound pressure value for the sound output (sound pressure) of the left and right microphones. 28a is stored.

  The operation of the present embodiment will be described based on specific numerical examples. For example, in the sensitivity adjustment mode, it is assumed that the sound level measured in step S104 is −74.8 dB at 1 kHz, −79.8 dB at 2 kHz, and −85.2 dB at 4 kHz. When viewed from these three frequencies, the lowest sound level in the user's usage environment is 4 kHz. Therefore, 4 kHz is selected as the adjustment audio frequency, and the reference sound is generated from the speaker 40 at the adjustment reference frequency 4 kHz.

  The reference sound from the R microphone 12R and the L microphone 12L is taken in, the 4 kHz component is extracted by the filtering processing devices 18R and 18L, and the sound level is measured by the level measuring devices 26R and 26L (S109). Assume that the 4 kHz audio level of the R channel is −29.6 dB and the 4 kHz audio level of the L channel is −25.6 dB.

  The measured sound levels of the R channel and the L channel are respectively compared with the 4 kHz reference sound levels of the R channel and the L channel stored in the reference sound level storage unit 28a (S110). The comparison difference value between the R channel and the L channel is set as a level correction value in the level adjusting devices 24R and 24L (S115). In the example described here, the reference audio level of the R channel is −28.1 dB (symbol 206), so the correction value is −29.6 − (− 28.1) = 1.5 (dB). Become. On the other hand, since the reference audio level of the L channel is −24.1 dB (reference numeral 209), the correction value is −25.6 − (− 24.1) = 1.5 (dB).

  In this way, sensitivity changes and sensitivity shifts due to aging degradation of the R microphone 12R and the L microphone 12L can be corrected to the sensitivity state at the time of shipment by the level adjustment of the level adjustment devices 24R and 24L.

  As the reference sound generating means, the speaker 40 having different distances from the R microphone 12R and the L microphone 12L is illustrated, but this is a general example, and the same method is used even when the built-in sound source located at the same distance is used. The sensitivity can be adjusted with.

  The frequencies 1 kHz, 2 kHz, and 4 kHz described here are examples, and it is obvious that reference sounds of other frequencies or frequency bands may be used.

  In the present embodiment, since the reference sound is generated from the built-in speaker 40 at a frequency that is less influenced by the ambient sound, accurate sensitivity adjustment can be realized. If a reference sound in a wide frequency band is used, it takes time to adjust the sensitivity while finely adjusting the filtering coefficients of the filtering processing devices 18R and 18L. However, in this embodiment, the processing is completed in a short time. If anomalous sound continues for a long time, the user will feel uncomfortable, but there are few such problems.

  Although the example which consists of R microphone and L microphone which comprise a stereo microphone as an audio | voice input means was shown, it is not necessarily limited to a thing for stereo, It is applicable to the structure which uses a several microphone.

  By applying filtering that passes only the frequency components of the reference sound to the reference sound, the current microphone sensitivity can be measured without being affected by other frequency bands, and an appropriate sensitivity correction value can be determined. .

  FIG. 8 is a flowchart illustrating another sensitivity adjustment operation according to this embodiment. Between step S103 and step S104 in FIG. 3, step S120 for checking in advance whether the sound level of the ambient sound is within the threshold is inserted. That is, the sensitivity adjustment is executed only when the environment is quieter than a certain level.

  Explaining the changed portion, after acquiring the ambient sound (103), the control device 22 determines whether or not the sound level of the acquired ambient sound is equal to or less than a predetermined threshold (S120). For example, it is checked whether the lowest one of the measured sound levels of a plurality of frequencies is equal to or less than a threshold value. If it is within the threshold (S120), the control device 22 executes step S104 and subsequent steps. When the threshold value is exceeded (S120), the sensitivity adjustment correction operation is terminated (S116).

  Environments with a high ambient sound are unsuitable for sensitivity adjustment in the first place, and there is a high possibility that sensitivity adjustment in such an environment will produce inappropriate results. By inserting step S120, it is possible to prevent sensitivity adjustment from being performed in such an unsuitable environment.

  FIG. 9 is a flowchart showing still another sensitivity adjustment operation according to this embodiment. Step S121 for giving a predetermined warning to the user is added to the flow shown in FIG.

  The changed part will be described. When the sound level of the acquired ambient sound is not equal to or lower than the predetermined threshold (S120), the control device 22 warns the user that the sensitivity adjustment is not performed (S121). Specifically, the control device 22 displays a predetermined warning on the display device 42 or generates a warning sound or explanation sound from the speaker 40. After the warning (S121), the control device 22 ends the sensitivity adjustment correction operation (S116).

  Even when the correction number counter N exceeds the predetermined value N0 (S113), the control device 22 similarly outputs a warning (S121), and then ends the sensitivity adjustment correction operation (S116).

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

Claims (4)

A voice processing device that adjusts the sensitivity of each voice input from a plurality of voice input means,
A plurality of filtering processing means for respectively filtering the input voices of the plurality of voice input means;
A plurality of spectrum measuring means for measuring levels of input voices of the plurality of voice input means for a plurality of frequencies;
A plurality of level measuring means for respectively measuring levels of output audio signals of the plurality of filtering processing means;
A plurality of level adjusting means for respectively adjusting levels of output audio signals of the plurality of filtering processing means;
Sound generating means;
In response to an instruction to start sensitivity correction, the spectrum measuring means causes the sound generating means to generate a reference sound of the adjustment sound frequency corresponding to a low sound level frequency among ambient sounds, and other than the adjustment sound frequency And a control means for setting a filtering coefficient in the filtering processing means so as to cut the signal and correcting the filtering coefficient according to a difference between an output sound level of the filtering processing means and a reference sound level. Processing equipment.   The audio processing apparatus according to claim 1, wherein the control unit corrects the filtering coefficient when the difference exceeds a predetermined threshold, and does not perform the filtering coefficient when the difference does not exceed the predetermined threshold. .   The voice processing apparatus according to claim 2, further comprising warning means for generating a warning when the filtering coefficient is not corrected.   An imaging apparatus comprising the audio processing apparatus according to claim 1.

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