JP6217380B2 - Electronic device, sensitivity difference correction method, and program - Google Patents

Description

  The disclosed technology relates to an electronic apparatus, a sensitivity difference correction method, and a program.

  In order to adjust the sensitivity difference between the two microphones in an electronic device having two microphones, the input signals of the two microphones are observed for a long period of time, the minimum value of the input signals is determined, and the minimum value is determined based on the minimum value. Then, a scale for adapting the sensitivity of one microphone to the sensitivity of the other microphone is obtained. By applying the scale to the sensitivity of the other microphone, the sensitivity difference between the two microphones is dynamically adjusted.

Special table 2003-527012 gazette

“Triaxial Acceleration Sensor Application Note”, [online], February 2007, Hokuriku Electric Industry Co., Ltd., [December 1, 2013 search], Internet (URL: http://www.hdk.co.jp) /pdf/AP_Note/anham04_v1.01.pdf)

  When the distance between the sound source and the microphone is close and the distance between the sound source and the microphone fluctuates, it is difficult to obtain an appropriate minimum value, so the sensitivity difference between the two microphones is appropriate. It may be difficult to adjust.

  An object of the disclosed technique is to appropriately adjust a sensitivity difference between a plurality of microphones by correcting microphone sensitivity based on an audio signal indicating a plane wave.

  In the disclosed technology, the first microphone outputs a first sound signal corresponding to the detected sound. The second microphone has a detection direction corresponding to the first microphone, is spaced apart from the first microphone, and outputs a second audio signal corresponding to the detected sound. The sensitivity difference accumulating unit determines whether a plane wave is detected based on one of the first audio signal and the second audio signal. If the determination is affirmative, data indicating a sensitivity difference represented by a difference between the power calculated based on the first audio signal and the power calculated based on the second audio signal is accumulated. The sensitivity correction unit uses the sensitivity difference correction value determined based on the representative value obtained from the data indicating the sensitivity difference accumulated in the sensitivity difference accumulation unit, and uses the first audio signal and the second audio signal. The sensitivity of the other audio signal is corrected.

  As one aspect, the disclosed technology has an effect that a sensitivity difference between a plurality of microphones can be appropriately adjusted by correcting the microphone sensitivity based on an audio signal indicating an audio that is a plane wave. Have.

It is a block diagram which shows an example of the principal part function of the smart device which concerns on embodiment. It is a block diagram which shows an example of a structure of the electric system of the smart device which concerns on embodiment. It is a flowchart which shows an example of the flow of the sensitivity difference correction process which concerns on embodiment. It is a flowchart which shows an example of the flow of the sensitivity difference accumulation | storage process which concerns on embodiment. It is a flowchart which shows an example of the flow of the plane wave detection process which concerns on embodiment. It is a flowchart which shows an example of the flow of the inclination detection process which concerns on embodiment. It is a flowchart which shows an example of the flow of the sensitivity correction process which concerns on embodiment.

  Hereinafter, an example of an embodiment of the disclosed technology will be described in detail with reference to the drawings. In the following description, a smart device will be described as an example of an electronic apparatus according to the disclosed technology, but the disclosed technology is not limited thereto. The disclosed technology can be applied to various electronic devices such as an IC recorder, a game machine, a car navigation device, a mobile phone, and a digital camera.

  As an example, the smart device 10 illustrated in FIG. 1 includes a sensitivity difference accumulation unit 12, a sensitivity correction unit 14, a tilt detection unit 16, and a storage unit 18. The sensitivity correction unit 14 is connected to the storage unit 18.

  The sensitivity difference accumulation unit 12 uses the inclination of the smart device 10 detected by the inclination detection unit 16 to accumulate data indicating the sensitivity difference between the two microphones to generate a sensitivity difference histogram. Store in the storage unit 18. Using the sensitivity difference histogram stored in the storage unit 20, the sensitivity of one of the two microphones is corrected.

  As shown in FIG. 2 as an example, the smart device 10 includes a CPU (Central Processing Unit) 60, a primary storage unit 62, a secondary storage unit 64, an external interface 70, a first microphone 72, a second microphone 74, and an acceleration. A sensor 76 is provided. The CPU 60, the primary storage unit 62, the secondary storage unit 64, the external interface 70, the first microphone 72, the second microphone 74, and the acceleration sensor 76 are connected to each other via a bus 78.

  The first microphone 72 and the second microphone 74 detect sound and convert it into sound signals. The voice detection direction of the first microphone 72 corresponds to the voice detection direction of the second microphone. The acceleration sensor 76 detects the tilt of the smart device 10 and converts the tilt into a digital value. An external device is connected to the external interface 70 and controls transmission / reception of various information between the external device and the CPU 60.

  The primary storage unit 62 is a volatile memory such as a RAM (Random Access Memory), for example. The secondary storage unit 64 is a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The primary storage unit 62 and the secondary storage unit 64 function as the storage unit 18 in FIG.

  As an example, the secondary storage unit 64 stores a sensitivity difference correction program 66 including a sensitivity difference accumulation subprogram 66A and a sensitivity correction subprogram 66B, and a sensitivity difference histogram 68. The sensitivity difference histogram 68 is a histogram in which the horizontal axis represents the sensitivity difference between the first microphone 72 and the second microphone 74 and the vertical axis represents the frequency of appearance of the sensitivity difference. The CPU 60 reads the sensitivity difference accumulation subprogram 66A and the sensitivity correction subprogram 66B from the secondary storage unit 64 and develops them in the primary storage unit 62. The CPU 60 operates as the sensitivity difference accumulation unit 12 illustrated in FIG. 1 by executing the sensitivity difference accumulation subprogram 66A. The CPU 60 operates as the sensitivity correction unit 14 illustrated in FIG. 1 by executing the sensitivity correction subprogram 66B.

  Next, as an operation of the embodiment of the disclosed technique, a sensitivity difference correction process performed by the smart device 10 by the CPU 60 executing the sensitivity difference correction program 66 will be described with reference to FIG.

  The sensitivity difference correction process is a process for correcting the sensitivity difference between the first microphone 72 and the second microphone 74. In the sensitivity difference correction process, for example, when the user presses a hard key of the smart device 10 or a button displayed on the display of the smart device 10, the user indicates an intention to input sound into the smart device 10. Start with.

  First, in steps 102 to 108, the sensitivity difference histogram 68 is generated by accumulating data indicating the sensitivity difference between the first microphone 72 and the second microphone 74. In step 102, an initial value 0 is set to the variable C. In step 104, it is determined whether or not the value of the variable C exceeds a predetermined number N of frames for generating the sensitivity difference histogram 68, for example, 1000. For audio signal processing, one unit of an audio signal divided for each predetermined time length is called a frame. If the determination is negative, a sensitivity difference accumulation process shown in detail in FIG. 4 is performed in step 106, 1 is added to variable C in step 108, and the process returns to step 104.

  If the determination in step 104 is affirmative, that is, if it is determined that data indicating a sensitivity difference of a predetermined number of frames N has been accumulated, the first microphone 72 and the second microphone are determined in steps 110 to 114. The sensitivity difference of 74 is corrected. In step 110, sensitivity difference accumulation processing shown in detail in FIG. 4 is performed. In step 112, sensitivity correction processing shown in detail in FIG. 7 is performed.

  In step 114, for example, it is determined whether or not the user has pressed a hard key of the smart device 10 or a button displayed on the display of the smart device 10. If the determination is negative, it is determined that the user does not indicate the intention to end the voice input to the smart device 10, and the process returns to step 110. If the determination in step 114 is affirmative, the sensitivity difference correction process is terminated.

  FIG. 4 shows details of the sensitivity difference accumulation process in step 106 of FIG. In step 122, sound is detected by the first microphone 72 and the second microphone 74, and a sound signal corresponding to the sound is accumulated in the primary storage unit 62. In step 124, it is determined whether one frame of audio is detected at a predetermined sampling rate. If the determination is negative, the process returns to step 122.

If the determination is affirmative, in step 126, one frame of the audio signal x ₁ [i] (i = 1,..., S, S is the number of samplings of one frame corresponding to the sound detected by the first microphone 72. ) Is acquired from the primary storage unit 62. Using the audio signal x ₁ [i], the first power P ₁ (t), which is the power value of the first microphone 72, is calculated by the equation (1). t is an integer indicating a frame.
... (1)

  The time length corresponding to one frame may be, for example, 20 milliseconds, the sampling rate may be, for example, 8 kHz, and the number of samplings may be, for example, 160 times.

  In step 128, a plane wave detection process for determining whether or not the sound detected by the first microphone 72 is a plane wave is performed. Since the plane waves have the same sound pressure regardless of the sound detection position, if the attitude of the smart device 10 changes by a predetermined angle or more and the change in the sound power value detected by the first microphone 72 is not more than a predetermined value, It is determined that the wave is a plane wave. If the attitude of the smart device 10 changes by a predetermined angle or more and the change in the power value of the sound detected by the first microphone 72 exceeds the predetermined value, it is determined that the wave is not a plane wave. If the attitude of the smart device 10 does not change by more than a predetermined angle, it means that the detection position has not changed, and therefore it is not determined whether the sound detected by the first microphone 72 is a plane wave. Details of the plane wave detection processing are shown in FIG.

  In the plane wave detection process, in step 142, an inclination detection process for detecting the inclination of the smart device 10 is performed. Details of the tilt detection process are shown in FIG. Note that the inclination detection by the acceleration sensor 76 is described in detail in, for example, Non-Patent Document 1, and the detailed description thereof is omitted.

  In the tilt detection process, in step 162, digital values generated based on the acceleration in the x-axis direction, the y-axis direction, and the z-axis direction of the smart device 10 detected by the acceleration sensor 76 are acquired. In step 164, the tilt angle θx (t) of the x axis is calculated based on the digital value generated based on the acceleration in the x axis direction and the z axis direction in step 162. In step 166, the y-axis tilt angle θy (t) is calculated based on the digital value generated in step 162 based on the acceleration in the y-axis direction and the z-axis direction.

  In step 168, the absolute value Δθx of the difference between the x-axis tilt angle θx (t) of the current frame t and the x-axis tilt angle θx (t−1) of the previous frame t−1 is calculated. In step 170, the absolute value Δθy of the difference between the y-axis tilt angle θy (t) of the current frame t and the y-axis tilt angle θy (t-1) of the previous frame t−1 is calculated.

  In step 172, it is determined whether or not Δθx exceeds a predetermined threshold THθx (for example, 10 degrees). If the determination in step 172 is affirmative, it means that the smart device 10 has been tilted by a predetermined angle or more compared to the previous frame, so that the tilt detection flag is set to 1 in step 178 and tilt detection processing is performed. Exit.

  If the determination in step 172 is negative, it is determined in step 174 whether Δθy exceeds a predetermined threshold THθy (for example, 10 degrees). If the determination in step 174 is affirmative, it means that the smart device 10 has been tilted by a predetermined angle or more compared to the previous frame. Therefore, the tilt detection flag is set to 1 in step 178 and tilt detection processing is performed. Exit.

  If the determination in step 174 is negative, it means that the inclination of the smart device 10 has not changed by a predetermined angle or more compared to the previous frame, so the inclination detection flag is set to 0, and the inclination detection process is performed. Exit.

In step 144 of FIG. 5, it is determined whether or not the tilt detection flag is 1. If the determination is positive, in step 146, the absolute value of the difference between the first power P ₁ (t) of the current frame of the first microphone 72 and the first power P ₁ (t-1) of the previous frame. Is less than a predetermined threshold THP (for example, 6 dB). If the determination is affirmative, the posture of the current frame of the smart device 10 is tilted by a predetermined amount or more compared to the posture of the previous frame, and the first power of the current frame of the first microphone 72 and the previous one The difference from the first power of the frame is sufficiently small. Therefore, it is determined that the sound detected by the first microphone 72 is a plane wave, and in step 148, the plane wave detection flag is set to 1, and the plane wave detection process is terminated.

  If it is determined in step 146 that the change in the first power of the first microphone 72 is not sufficiently small compared to the previous frame, the sound detected by the first microphone 72 is not a plane wave. That is. Accordingly, in step 150, the plane wave detection flag is set to 0, and the plane wave detection process is terminated.

  If it is determined in step 144 that the tilt detection flag is 0, it is not determined whether the sound detected by the first microphone 72 is a plane wave. Therefore, in step 150, it is assumed that the sound detected by the first microphone 72 is not a plane wave, and the plane wave detection flag is set to 0, and the plane wave detection process ends.

In step 130 of FIG. 4, it is determined whether or not the plane wave detection flag is 1, that is, whether or not the sound detected by the first microphone 72 is a plane wave. If it is determined that the plane wave detection flag is 1, one frame of the audio signal x ₂ [i] (i = 1,..., S) corresponding to the audio detected by the second microphone 74 in step 132. , S is the number of times of sampling for one frame) from the primary storage unit 62. Using the audio signal x ₂ [i], the second power P ₂ (t), which is the power value of the second microphone 74, is calculated by the equation (2). t is an integer indicating a frame.
... (2)

In step 134, data indicating the sensitivity difference is accumulated, that is, the sensitivity difference histogram 68 is updated using the data indicating the sensitivity difference. Specifically, the difference between the first power P ₁ (t) of the first microphone 72 and the second power P ₂ (t) of the second microphone is calculated. One is added to the bin of the sensitivity difference histogram 68 including the difference, and the sensitivity difference accumulation process is terminated. The bin width may be 3 dB, for example.

  When it is determined in step 130 that the plane wave detection flag is 0, the sensitivity difference histogram 68 is not updated, and the sensitivity difference accumulation process is terminated. That is, the sensitivity difference histogram 68 is updated only when the sound detected by the first microphone 72 is a plane wave.

  Since the sensitivity difference accumulation process in step 110 is the same as the sensitivity difference accumulation process in step 106, the description thereof is omitted.

  Details of the sensitivity correction processing in step 112 are shown in FIG. In step 182, a representative value for the second microphone 74 is set based on the sensitivity difference between the first microphone 72 and the second microphone 74 indicated by the bin indicating the mode value. The representative value may be the minimum value of the bin sensitivity difference indicating the mode value. For example, when the minimum value of the sensitivity difference indicated by the bin indicating the mode value is 9 db, the representative value may be 9 dB.

In step 184, a sensitivity difference correction value is calculated based on the representative value. When the representative value is M, the sensitivity difference correction value is calculated as m = 10 ^{M / 20} . m is the ratio of the audio signal of the first microphone 72 to the audio signal of the second microphone 74.

In step 186, the sensitivity of the audio signal of the second microphone 74 is corrected by multiplying the audio signal x ₂ [i] of the second microphone 74 by the sensitivity correction value. Thereby, the sensitivity difference between the first microphone 72 and the second microphone 74 is corrected.

Specifically, when the audio signal corresponding to the audio of the current frame t detected by the second microphone 74 is x ₂ [i] (i = 0,..., S, S is the number of samples in one frame), 3) The sensitivity of the audio signal of the second microphone 74 is corrected by the equation (3). xa ₂ [i] is the corrected audio signal of the second microphone 74.
xa ₂ [i] = x ₂ [i] × m (3)

  In the present disclosure, when the sound detected by the first microphone 72 is a plane wave, data indicating a sensitivity difference that is a difference between the power value of the first microphone 72 and the power value of the second microphone 74 is accumulated in the sensitivity difference histogram 68. The mode value of the sensitivity difference histogram 68 is used as a representative value. The sensitivity difference between the first microphone 72 and the second microphone 74 is corrected by correcting the sound signal indicating the sound detected by the second microphone 74 with the sensitivity difference correction value obtained from the representative value. In this way, regardless of the detection position, it is possible to appropriately adjust the sensitivity difference between multiple microphones by correcting the microphone sensitivity based on the audio signal indicating the sound that is a plane wave having the same sound pressure. It becomes.

  In the above description, the correction of the sensitivity difference between the first microphone 72 and the second microphone 74 has been described, but the present disclosure is not limited to this. When the smart device 10 has a third microphone in addition to the first microphone 72 and the second microphone 74, the first microphone 72 and the second microphone 74 are corrected by correcting the sensitivity of the third microphone in the same manner as the second microphone 74. It is possible to correct the sensitivity difference between the third microphone and the third microphone. Even when the number of microphones exceeds three, it is possible to correct the sensitivity difference between the microphones.

  In the above description, the sensitivity of the audio signal of the second microphone 74 is corrected, but the present disclosure is not limited to this. For example, the sensitivity of the audio signal of the first microphone 72 may be corrected, or the sensitivity of the audio signal of the first microphone 72 and the second microphone 74 may be corrected.

  In the above description, the acceleration sensor 76 is used to detect the tilt of the smart device 10, but the present disclosure is not limited thereto. For example, a geomagnetic sensor or a gyro sensor may be used.

  In the above, the minimum value of the sensitivity difference indicated by the bin indicating the mode value is used as the sensitivity difference correction value, but the present disclosure is not limited to this. For example, the maximum value or the median value of the sensitivity difference indicated by the bin indicating the mode value may be used.

  In the above, the sensitivity difference indicated by the bin indicating the mode value in the sensitivity difference histogram 68 is set as the representative value, but the present disclosure is not limited to this. For example, an average value or an intermediate value of data indicating the accumulated sensitivity difference may be set as the representative value.

  When the smart device 10 performs the sensitivity difference correction process for the second time or later, the sensitivity difference histogram 68 used in the first sensitivity difference correction process may be used. In this case, the processing of steps 102 to 108 in FIG. 3 can be omitted. Therefore, in the second and subsequent sensitivity difference correction processes, the processing load can be reduced and the processing time can be shortened.

  When the sensitivity difference correction process is performed for the second time or later in the smart device 10, the processes in steps 104 to 108 in FIG. 3 may be repeated a smaller number of times than the first time (for example, 1/10 of the first time). For example, the difference between the sensitivity difference indicated by the bin indicating the mode value and the representative value at the end of the previous sensitivity difference correction process (for example, the first time for the second process) is a predetermined value (for example, 3 dB). If it is below, the processing of steps 104 to 108 in FIG. Thereafter, the process may proceed to a sensitivity difference accumulation process in step 110. When the difference between the sensitivity difference indicated by the bin indicating the mode value and the representative value at the end of the previous sensitivity difference correction process exceeds a predetermined value (for example, 3 dB), the processes of steps 104 to 108 are performed. Repeat the same number of times as the first time.

  When the sum of the frequencies (the number of data indicating the sensitivity difference) in the sensitivity difference histogram 68 reaches a predetermined value (for example, 2000), a predetermined value (for example, 1900/2000) is set for each frequency in the bin of the sensitivity difference histogram 68. You may make it multiply. As a result, it is possible to suppress the total frequency of the sensitivity difference histogram 68, and to reduce the processing load.

  After the sensitivity difference correction process is completed, the sensitivity difference histogram 68 is stored in the external server via the external interface 70, and is received from the external server via the external interface 70 when the next sensitivity difference correction process is performed. May be. As a result, in the second and subsequent sensitivity difference correction processes, the processes in steps 104 to 108 can be omitted.

  In FIG. 2, the sensitivity difference correction program 66 is stored (installed) in the secondary storage unit 64 in advance, but the present disclosure is not limited to this. For example, the sensitivity difference correction program 66 may be stored in a non-temporary storage medium such as a CD-ROM or a DVD-ROM. The sensitivity difference correction program 66 stored in the non-temporary storage medium may be read from the secondary storage unit 64 after being installed in the secondary storage unit 64 and expanded in the primary storage unit 62. It may be read directly from the non-temporary storage medium and expanded in the primary storage unit 62.

  The sensitivity difference correction program 66 may be stored in an external server. The sensitivity difference correction program 66 stored in the external server is installed in the secondary storage unit 64 via the external interface 702, read out from the secondary storage unit 64, and expanded in the primary storage unit 62. Good. Alternatively, the sensitivity difference correction program 66 stored in the external server may be read directly from the external server and expanded in the primary storage unit 62.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1)
A first microphone (FIG. 2: 72) for outputting a first audio signal corresponding to the detected audio;
A detection direction is a direction corresponding to the first microphone, a second microphone (FIG. 2: 74) that is disposed apart from the first microphone and outputs a second audio signal corresponding to the detected audio;
When it is determined that a plane wave is detected based on one of the first audio signal and the second audio signal, the power calculated based on the first audio signal and the second audio signal A sensitivity difference accumulating unit (FIG. 1:12) for accumulating data indicating a sensitivity difference represented by the difference between the power calculated based on
Using the sensitivity difference correction value determined based on the representative value obtained from the data indicating the sensitivity difference accumulated in the sensitivity difference accumulation unit, the other audio signal of the first audio signal and the second audio signal A sensitivity correction unit (FIG. 1:14) for correcting the sensitivity of
An electronic device (FIG. 1: 10).

(Appendix 2)
It further comprises a sensor (FIG. 2: 76) for detecting tilt fluctuation of the electronic device
The sensitivity difference accumulating unit has a tilt variation of the electronic device within a predetermined time that is equal to or greater than a predetermined angle, and a variation of the power calculated based on the one audio signal within the predetermined time is smaller than a predetermined value. If it is determined that a plane wave has been detected,
The electronic device according to attachment 1.

(Appendix 3)
The representative value is a mode value of data indicating the sensitivity difference.
The electronic device according to Supplementary Note 1 or Supplementary Note 2.

(Appendix 4)
The sensitivity difference correction value is a ratio of the one audio signal to the other audio signal obtained from the representative value.
The electronic device in any one of appendix 1-3.

(Appendix 5)
Correcting the sensitivity of the other audio signal by multiplying the other audio signal by the sensitivity difference correction value;
The electronic device according to attachment 4.

(Appendix 6)
Computer
The first audio signal output according to the sound detected by the first microphone disposed in the electronic device, and the detection direction is a direction corresponding to the first microphone, and the electronic device is separated from the first microphone. When it is determined that a plane wave is detected based on one of the second audio signals output according to the audio detected by the arranged second microphone, the calculation is performed based on the first audio signal. Data indicating the difference in sensitivity expressed by the difference between the power to be calculated and the power calculated based on the second audio signal (FIG. 3: 106, 110),
Using the sensitivity difference correction value determined based on the representative value obtained from the accumulated data indicating the sensitivity difference, the sensitivity of the other audio signal of the first audio signal and the second audio signal is corrected ( Figure 3: 112),
Sensitivity difference correction method.

(Appendix 7)
Detecting inclination fluctuation of the electronic device (FIG. 5: 142);
A plane wave is detected when an inclination variation of the electronic device within a predetermined time is equal to or greater than a predetermined angle and a variation of the power calculated based on the one audio signal is smaller than a predetermined value. Determine (FIG. 5: 146),
The sensitivity difference correction method according to claim 6.

(Appendix 8)
The representative value is a mode value of data indicating the sensitivity difference.
The sensitivity difference correction method according to appendix 6 or appendix 7.

(Appendix 9)
The sensitivity difference correction value is a ratio of the one audio signal to the other audio signal obtained from the representative value.
The sensitivity difference correction method according to any one of appendices 6 to 8.

(Appendix 10)
Correcting the sensitivity of the other audio signal by multiplying the other audio signal by the sensitivity difference correction value;
The sensitivity difference correction method according to appendix 9.

(Appendix 11)
The first audio signal output according to the sound detected by the first microphone disposed in the electronic device, and the detection direction is a direction corresponding to the first microphone, and the electronic device is separated from the first microphone. When it is determined that a plane wave is detected based on one of the second audio signals output according to the audio detected by the arranged second microphone, the calculation is performed based on the first audio signal. Data indicating the difference in sensitivity expressed by the difference between the power to be calculated and the power calculated based on the second audio signal (FIG. 3: 106, 110),
Using the sensitivity difference correction value determined based on the representative value obtained from the accumulated data indicating the sensitivity difference, the sensitivity of the other audio signal of the first audio signal and the second audio signal is corrected ( Figure 3: 112),
A program for causing a computer to execute sensitivity difference correction processing.

(Appendix 12)
Detecting inclination fluctuation of the electronic device (FIG. 5: 142);
When the detected variation in tilt of the electronic device within a predetermined time is equal to or greater than a predetermined angle and the variation in the power calculated based on the one audio signal is smaller than a predetermined value, a plane wave is generated. It is determined that it has been detected (FIG. 5: 146),
The program according to claim 11.

(Appendix 13)
The representative value is a mode value of data indicating the sensitivity difference.
The program according to appendix 11 or appendix 12.

(Appendix 14)
The sensitivity difference correction value is a ratio of the one audio signal to the other audio signal obtained from the representative value.
The program according to any one of appendices 11 to 13.

(Appendix 15)
Correcting the sensitivity of the other audio signal by multiplying the other audio signal by the sensitivity difference correction value;
The program according to appendix 14.

10 Smart device 60 CPU
62 Primary storage unit 64 Secondary storage unit 72 First microphone 74 Second microphone 76 Acceleration sensor

Claims (7)

A first microphone that outputs a first audio signal corresponding to the detected audio;
A second microphone that has a detection direction corresponding to the first microphone, is disposed apart from the first microphone, and outputs a second audio signal corresponding to the detected audio;
When it is determined that a plane wave is detected based on one of the first audio signal and the second audio signal, the power calculated based on the first audio signal and the second audio signal A sensitivity difference accumulation unit that accumulates data indicating a sensitivity difference represented by a difference between the power calculated based on the power,
Using the sensitivity difference correction value determined based on the representative value obtained from the data indicating the sensitivity difference accumulated in the sensitivity difference accumulation unit, the other audio signal of the first audio signal and the second audio signal A sensitivity correction unit for correcting the sensitivity of
Electronic equipment comprising. It further comprises a sensor for detecting inclination fluctuation of the electronic device,
The sensitivity difference accumulating unit has a tilt variation of the electronic device within a predetermined time that is equal to or greater than a predetermined angle, and a variation of the power calculated based on the one audio signal within the predetermined time is smaller than a predetermined value. If it is determined that a plane wave has been detected,
The electronic device according to claim 1. The representative value is a mode value of data indicating the sensitivity difference.
The electronic device according to claim 1 or 2. The sensitivity difference correction value is a ratio of the one audio signal to the other audio signal obtained from the representative value.
The electronic device of any one of Claims 1-3. Correcting the sensitivity of the other audio signal by multiplying the other audio signal by the sensitivity difference correction value;
The electronic device according to claim 4. The first audio signal output according to the sound detected by the first microphone disposed in the electronic device, and the detection direction is a direction corresponding to the first microphone, and the electronic device is separated from the first microphone. When it is determined that a plane wave is detected based on one of the second audio signals output according to the audio detected by the arranged second microphone, the calculation is performed based on the first audio signal. Data indicating a difference in sensitivity represented by the difference between the power to be calculated and the power calculated based on the second audio signal,
Using the sensitivity difference correction value determined based on the representative value obtained from the accumulated data indicating the sensitivity difference, the sensitivity of the other audio signal of the first audio signal and the second audio signal is corrected.
Sensitivity difference correction method. The first audio signal output according to the sound detected by the first microphone disposed in the electronic device, and the detection direction is a direction corresponding to the first microphone, and the electronic device is separated from the first microphone. When it is determined that a plane wave is detected based on one of the second audio signals output according to the audio detected by the arranged second microphone, the calculation is performed based on the first audio signal. Data indicating a difference in sensitivity represented by the difference between the power to be calculated and the power calculated based on the second audio signal,
Using the sensitivity difference correction value determined based on the representative value obtained from the accumulated data indicating the sensitivity difference, the sensitivity of the other audio signal of the first audio signal and the second audio signal is corrected.
A program for causing a computer to execute sensitivity difference correction processing.