JP3186892B2 - Wind noise reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reducing wind noise contained in a sound signal picked up by a microphone in an environment exposed to an airflow such as natural wind, exhalation, air conditioning and the like.

[0002]

2. Description of the Related Art A microphone converts a change in sound pressure due to sound waves into mechanical vibration of a diaphragm, and operates an electroacoustic conversion system based on the mechanical vibration to obtain an electric signal. Many. For this reason, when a desired sound is picked up by a microphone, if mechanical vibration is applied to the diaphragm due to some factor other than the desired sound, this becomes noise for the desired sound. In this case, if the above-mentioned factor is wind, noise due to wind (hereinafter referred to as wind noise)
Occurs.

As a method of reducing wind noise generated in a microphone, (1) use of a windscreen (windshield) (2) adoption of a configuration showing omnidirectionality in a low sound range (3) electric / acoustic high-pass filter (The cutoff frequency is fixed.)

[0004]

However, in the above method (1), the wind noise generally decreases as the external dimensions of the windscreen increase and as the distance between the microphone element and the inner wall of the windscreen increases. Therefore, there is a problem that a large windscreen must be prepared in order to sufficiently reduce the wind noise. This problem greatly hinders miniaturization and portability of the device.

In the above method (2), the microphone is omnidirectional rather than directional,
Used because of the low wind noise. But,
The effect of reducing the wind noise by this method is not so large, and in addition, the wind noise does not become a sufficiently low level due to the influence of the housing when configuring the microphone device.

The method (3) of using an electric / acoustic high-pass filter having a fixed cutoff frequency is effective because wind noise is mainly noise in a low frequency range. At the same time, the bass range of the desired sound is always reduced at the same time. Therefore, even when there is almost no wind noise or when the wind noise level is low, the sound pickup quality is reduced.

The present invention basically uses the method (3). However, it is possible to solve the above-mentioned problems and to obtain the best possible sound pickup quality while reducing wind noise. It is an object of the present invention to provide a wind noise reduction device that can be used.

[0008]

In order to solve the above-mentioned problems, a wind noise reduction device according to the present invention is provided with first and second microphones disposed close to each other, when corresponding to reference numerals in the embodiments described later. Elements 11 and 12, wind noise detecting means 15 for detecting a wind noise component by calculating a difference between outputs of the first and second microphone elements, and a plurality of filters.
A circuit including the first and / or the first circuit.
Or provided for the output signal of the second microphone element, a low frequency reduction characteristic variable high-pass filter 16, on the basis of the output of the wind noise detector, the plurality Fi
Filter or select one of the filter circuits
By controlling the combination of several filter circuits,
Ri, and a control unit 24 for controlling the low-frequency reduction characteristic of the high pass filter, characterized in that to obtain an audio output signal with reduced wind noise from the high-pass filter.

[0009]

FIG. 5 shows the spectrum of the wind noise of the microphone. As can be seen from FIG. 5, the wind noise is a noise whose main component is several hundred Hz or less. On the other hand, FIG. 6 shows a spectrum of a voice signal, which is a spectrum of a female voice. As is clear from FIG. 6, the audio signal is about 100 Hz.
It is distributed above.

In the wind noise reduction device according to the present invention having the above-described configuration, the high-pass filter for extracting the output audio signal has a low level.
A region reduction characteristic, for example, a cutoff frequency is controlled according to the level of wind noise.

That is, when the level of wind noise is large, the cutoff frequency of the high-pass filter is
Hz is set to a relatively high frequency, and wind noise is removed. When the level of the wind noise is small, it is not necessary to reduce the wind noise so much. Therefore, the cutoff frequency of the high-pass filter is set to a low frequency that is inversely proportional to the wind noise level of several hundred Hz or less, The low frequency component of the sound is obtained as an output sound signal as much as possible.

An embodiment of the wind noise reduction device according to the present invention will be described.
Before explaining, wind noise reduction to facilitate this invention
A configuration example of the device will be described with reference to FIGS.

In the example shown in FIG. 1, two microphone elements 11 and 12 are arranged close to each other. The microphone elements 11 and 12 having the same characteristics are used in this example, and for example, an omnidirectional microphone unit is used.

The output of one of the microphone elements 11 is converted into a digital signal by an A / D converter 13, and the digital signal is supplied to a wind noise reducing high-pass filter 16 having a variable cutoff frequency. And
The output signal of the high-pass filter 16 is supplied to a D / A converter 17 and returned to an analog signal.
Derived to 0. In this example, the high-pass filter 16 is constituted by a primary IIR digital filter.

FIG. 2 shows an example of a high-pass filter 16 constructed using the first-order IIR digital filter.
This is a delay circuit 1 having a delay time corresponding to a unit sample.
61, 162 and filter coefficient weighting circuits 163, 16
4, 165 and adders 166 and 167. a0, a1, b1 are filter coefficients, and by changing the filter coefficients a0, a1, b1,
The cutoff frequency of the high-pass filter 16 changes.

The output of the other microphone element 12 is converted into a digital signal by the A / D converter 14, and the digital signal is supplied to a subtraction circuit 15. In the subtraction circuit 15, a difference between a digital signal output from the microphone element 11 from the A / D converter 13 and a digital signal output from the other microphone element 12 is obtained.

When sound is collected in an environment where wind noise is generated by the apparatus shown in FIG. 1, the outputs of the microphone elements 11 and 12 include wind noise in the collected sound signal. As described above, since the two microphone elements 11 and 12 are arranged close to each other, sound is picked up in a state where the two microphone elements 11 and 12 have a very strong correlation. On the other hand, the wind noise generated in the microphone element 11 and the microphone element 12 due to the wind is unique to each microphone element, so that there is no correlation between the wind noises of both microphone elements.

Accordingly, when the subtraction circuit 15 performs a difference operation between the outputs of the two microphone elements 11 and 12, the audio signal is canceled, and the wind noise component is obtained from the subtraction circuit 15.

The wind noise component from the subtraction circuit 15 is supplied to an averaging circuit 18. The averaging circuit 18 is constituted by a low-pass filter or a circuit having the same function as the low-pass filter. This makes the degree of change in the cutoff frequency of the high-pass filter for wind noise reduction gradual by averaging the wind noise. This allows
It is possible to suppress the occurrence of distortion caused by high frequency components of noise and wind noise.

The output of the averaging circuit 18 is supplied to the control circuit 1
9. The control circuit 19 includes an averaging circuit 18
, That is, the cutoff frequency of the high-pass filter 16 is controlled in accordance with the amount of wind noise (power). That is, the control circuit 19 obtains the values of the filter coefficients a0, a1, and b1 of the digital IIR filter in accordance with the following algorithm for updating coefficients (1), (2), and (3), and obtains the wind noise. Control the cutoff frequency according to the power of the

A0 = −0.998692 + μ × X × X (1) a1 = 0.998692−μ × X × X (2) b1 = −0.997385 + 2μ × X × X (3) where μ is a constant, X Is the output signal level of the averaging circuit 18.

Therefore, when the power X of the wind noise is zero, the above equations (1) to (3) are as follows: a0 = −0.998692 a1 = 0.998692 b1 = −0.997385 The characteristic of the filter composed of this value is
As shown in FIG. 3, the high-pass filter has a cutoff frequency of 20 Hz.

When the wind noise has a certain value, the coefficients a 0, a 1, b in accordance with the amount X of the wind noise become higher when the amount X of the wind noise increases.
The value of 1 changes. That is, when a small amount of wind noise, the cutoff frequency of the high pass filter 16 is low, as obtained at the output even low-frequency components of the microphone picked-up sound. On the other hand, when the amount of wind noise is large,
The cutoff frequency of the high-pass filter 16 is set to several hundred Hz mainly including wind noise, and the wind noise is sufficiently reduced.

FIG. 4 is a table showing the values of the coefficients a0, a1, and b1 at several cut-off frequencies of the high-pass filter 16 composed of a primary IIR digital filter.

FIGS. 7 to 12 experimentally confirm the effect of the apparatus of the above example, and the wind noise and the female voice shown in FIGS. 5 and 6 are simultaneously collected as input voices to be collected. In the case of being sounded In the case of only the wind noise in FIG. 5, three cases of the case of only the female voice in FIG. 6 are prepared, and the spectrum before and after the above-described wind noise reduction processing is compared for each case.

7 and 8 show spectra before and after the wind noise reduction processing when the wind noise and the female voice are picked up at the same time, respectively. 10 dB, it can be seen that it is improved after the processing.

FIGS. 9 and 10 show the spectrums before and after the above-described wind noise reduction processing in the case of only wind noise, respectively. You can see that it is done.

FIGS. 11 and 12 show the spectrums before and after the wind noise reduction processing for the case of only female voice, respectively. From this, it can be seen that there is almost no difference before and after the processing. It can be seen that when there is no wind noise, a low-frequency component of the collected sound can also be obtained without being affected by the high-pass filter.

As the high-pass filter 16, a second-order IIR digital filter 200 as shown in FIG. 13 can be used. This is because delay circuits 201, 202, 203, and 204 having a delay time corresponding to a unit sample and filter coefficient weighting circuits 206, 207, 208, and 209,
210, and adders 211, 212, and 213. a0, a1, a2, b1, b2 are filter coefficients, and these filter coefficients a0, a1, a2, b1, b1,.
By changing b2, the cutoff frequency of the filter 200 changes.

In this case, the filter coefficients a0, a1, a2
, B1, b2 are calculated by the following coefficient update equation (4),
The cutoff frequency is obtained according to the algorithm represented by (5), (6), (7), and (8), and the cutoff frequency is controlled according to the power of the wind noise in the same manner as described above.

A0 = 0.990786−μ × ε × X (4) a1 = −1.981573 + 2μ × ε × X (5) a2 = 0.990786−μ × ε × X (6) b1 = −1.981488 + 2μ × ε × X (7) b2 = 0.981658-2μ × ε × X (8) where μ is a constant, X is the output signal level of the averaging circuit 18, and ε is the system output.

FIG. 14 is a table showing the values of the coefficients a0, a1, a2, b1, and b2 at several cutoff frequencies of the secondary IIR digital filter 200.

Here, the characteristics of the primary and secondary IIR digital filters and equations (1) to (8) showing the algorithm for updating the filter coefficients will be described.

From the tables of FIG. 4 and FIG. 14, it can be seen that the amounts of change .DELTA.a0, .DELTA.a1, and .DELTA.b1 of the respective coefficients when the cutoff frequency changes from 100 Hz to 200 Hz have the following regularity. . Δa0 = −Δa1ａ2 × Δb1 Similarly, in the case of the second order, Δa0, Δa1, Δa2, Δb1,
Δb2 has the following regularity. Δa0 = Δa2 ≒ −2 × Δa1 ≒ −2 × Δb1 ≒ 2 × Δb2 The above relationship also holds for other frequencies. Therefore, the algorithm of the coefficient update performed using these relationships is represented by Expressions (1) to (8).

Next, the actual operation of the wind noise reduction device according to the present invention will be described.
An embodiment will be described with reference to FIG. Explained above
In the example of the wind noise reduction device , one of the primary IIR filter and the secondary IIR filter is used as the high-pass filter 16, but the wind noise reduction device according to the present invention is used.
The location, as a high-pass filter 16, a plurality of fill
It used those composed of capacitor circuit, by controlling the combination of selection or a plurality of filter circuit of one of the filter circuit which acts substantially as a high-pass filter 16 by the control circuit, to obtain a proper cutoff characteristics easily so
To be able to

FIG. 15 shows a wind noise reduction device according to the present invention .
FIG. 2 is a block diagram showing a configuration of one embodiment. The same parts as those in the above-described example are denoted by the same reference numerals. In this example
Thus, the high-pass filter 16 includes a plurality of filters of different orders.
It consists of a digital filter. That is, as shown in FIG.
Thus, in this example, the high-pass filter 16
It comprises a first digital filter 21, a second digital filter 22, and a switching circuit 23. Then, the average power of the wind noise from the averaging circuit 18 is supplied to the control circuit 24, and the output of the control circuit 24 switches the switching circuit 23. In this example, a first-order IIR filter is used as the first digital filter 21, and a second-order IIR filter is used as the second digital filter 22.

In this case, when the amount of wind noise is zero or very small, the switching circuit 23 is switched to the input terminal A, and the high-pass filter 16 substantially bypasses the first and second digital filters 21 and 22. A
The output signal of the / D converter 13 is supplied to the D / A converter 17 as it is.

If the wind noise has a certain amount and is equal to or less than a predetermined amount, the switching circuit 23
Is switched to the input terminal B, and the output signal of the A / D converter 13 is supplied to the D / A converter 17 only through the first digital filter 21. When the amount of wind noise increases and exceeds the predetermined amount, the switching circuit 2
3 is switched to the input terminal C, and the second digital filter 22 is cascade-connected to the first digital filter 21. The output of the A / D converter 13 is passed through these two digital filters 21 and 22 to the D / D converter.
It is supplied to the A converter 17.

In the example shown in FIG. 15, the first digital filter 21 may be constituted by a secondary IIR filter, and the second digital filter 22 may be constituted by a primary IIR filter. Further, two or more digital filters may be used in combination. Further, the digital filters 21 and 22 are controlled by the control circuit 24.
May be controlled in accordance with the filter coefficients.

In the above example, the cutoff frequency of the high-pass filter 16 is controlled only according to the power level of the wind noise. However, the desired sound obtained by passing the output of the A / D converter 13 through the high-pass filter is controlled. The cutoff frequency of the high-pass filter 16 may be controlled only in accordance with the output power of the high-pass filter 16. Further, by controlling the cutoff frequency of the high-pass filter while considering both the amount of desired sound and the amount of wind noise, it is possible to obtain a higher quality output sound signal.

FIG. 16 shows an embodiment of the present invention in which the cutoff frequency of the high-pass filter is controlled while considering both the amount of desired sound and the amount of wind noise. That is, in the example of FIG. 16, the output signal of the A / D converter 13 is supplied to the high-pass filter 16 and also to another high-pass filter 31 for mainly extracting only the audio signal. The output of the high-pass filter 31 is supplied to the level ratio detection circuit 32. The wind noise component from the subtraction circuit 15 is supplied to the level ratio detection circuit 32.

The level ratio detection circuit 32 detects the ratio between the level of the audio signal from the high-pass filter 31 and the level of the wind noise signal from the subtraction circuit 15, and outputs the detection output to the control circuit 33. And this control circuit 3
3 is a high-pass filter 1 according to the input level ratio.
6 is controlled. High pass filter 1
6 may be any of the configurations described above.

In the case of this example, the cutoff frequency of the high-pass filter is determined by the level ratio between the voice signal and the wind noise signal. By setting the off-frequency not so high, the influence on the desired sound can be reduced.

The audio signal obtained by passing the sum of the output of the microphone 11 and the output of the microphone 12 through the high-pass filter is converted to the above-mentioned high-pass filter 3.
1 may be used in place of the output.

The above example is an embodiment in which the present invention is applied to a microphone device, but the present invention can also be applied to a recording / reproducing device. FIG. 17 is a block diagram of a tape recording / reproducing apparatus according to an embodiment of the present invention.

That is, in this example, the audio signals picked up by the first and second microphones 11 and 12 are recorded by recording circuits 41 and 42 and recording amplifiers 43 and 44.
Are supplied to the recording heads 45 and 46 via the respective recording media, and are recorded on the magnetic tape 47 in two channels.

The two-channel signals recorded on the tape 47 are picked up from the tape 47 by the reproducing heads 51 and 52, respectively. Reproduction signals from the reproduction heads 51 and 52 are supplied to A / D converters 55 and 56 via reproduction amplifiers 53 and 54 and are converted into digital signals. The output of the A / D converter 55 is supplied to a D / A converter 58 through a high-pass filter 57 similar to the above-described high-pass filter 16, returned to an analog signal, and led to an output terminal 59.

In the subtraction circuit 60, the difference between the outputs of the A / D converters 55 and 56 is obtained, and the wind noise component contained in the reproduced signal is extracted. This wind noise signal is supplied to the control circuit 62 via the averaging circuit 61. The control circuit 62 controls the cut-off frequency of the high-pass filter 57 in accordance with the magnitude of the wind noise so that the cut-off frequency increases as the amount of the wind noise increases, as in the above-described example. Also in this example, the cutoff frequency of the high-pass filter 57 may be controlled according to the level ratio between the output of the A / D converter 55 and the output of the subtraction circuit 60.

As described above, according to the example of FIG.
A good reproduced audio signal can be obtained by removing a wind noise component included in the reproduced signal. At the time of recording, instead of recording the audio signals from the microphones 11 and 12 on two channels, the output of one or both microphones and the difference between the outputs of both microphones, that is, the wind noise component is recorded. Is also good. Furthermore, the output of a sensor for detecting the wind noise and the flow rate and flow velocity of the wind may be recorded on a recording medium such as a tape together with the audio signal.

The above is the case where the high-pass filter is constituted by a digital filter. However, the high-pass filter having a variable cutoff frequency may be constituted by an analog filter.

FIG. 18 shows an embodiment in which a high-pass filter having a variable cutoff frequency is constituted by an analog filter, in which the present invention is applied to the above-described microphone device. In the case of this example, the output signal of the microphone 11 is supplied to the high-pass filter 71 having an analog configuration.

The high-pass filter 71 includes a capacitor 72 and a transistor 73 as an example of a variable impedance element. Then, a wind noise signal from a subtraction circuit 74 for obtaining a difference between the output of the microphone 11 and the output of the microphone 12 is supplied to the base of the transistor 73 via a level detection circuit 75 as a control signal forming circuit.

When the amount of wind noise is close to zero, the base voltage of the transistor 73 becomes zero or a low level, so that the transistor 73 is turned off. Therefore, the high-pass filter 71 has a cut-off frequency of 0 or a very low frequency, and the audio signal output from the microphone 11 has an output terminal 7 with almost the same frequency characteristics.
6 is derived.

When the level of the wind noise increases, the base voltage of the transistor 73 increases in accordance with the magnitude of the wind noise, so that the impedance of the transistor 73 decreases, thereby reducing the cutoff frequency of the high-pass filter 73. It changes to the higher frequency side according to the magnitude of the wind noise.

As the variable impedance element,
It goes without saying that a photocoupler or the like can be used instead of the transistor 73. Even when an analog high-pass filter is used, a desired filter characteristic can be obtained by combining a plurality of analog filters as in the example of FIG.

In the above example, the wind noise is detected as the difference between the output signals of the two microphones. However, the magnitude of the wind noise is detected using a sensor for detecting the flow rate and flow velocity of the wind. You may make it.

Further, since the two microphone elements can be respectively allocated to the left and right channels, even when a stereo microphone is configured, it can be realized without increasing the number of microphone elements. In that case, a high-pass filter is inserted into each of the two microphone outputs, and the cut-off frequency of each high-pass filter is controlled according to the power of the wind noise, the power of the audio signal, and the ratio of both. To

Also, since the wind noise reduction operation is automatic, there is an advantage that the user can concentrate on other tasks, for example, monitoring a monitor image during shooting with a camera-integrated VTR.

In the above-described example, non-directional microphones are used as the two microphone elements 11 and 12, but these microphone elements may have any directivity. However, if an omnidirectional microphone is used, it is easy to handle and inexpensive, so that the practical effect is great.

It is also easy to obtain another directivity by combining two microphone elements. Moreover,
It is also easy to make it almost omnidirectional in the low frequency range and unidirectional in the middle and high frequency ranges. Of course, it is also possible to obtain a signal according to the gist of the present invention by using three or more microphone elements.

Further, instead of controlling the cut-off frequency of the high-pass filter, the steepness of the roll-off characteristic of the high-pass filter may be controlled to reduce wind noise.
The effect of improving the quality of the audio signal is obtained.

As described above, according to the present invention,
According to the magnitude of the wind noise or the ratio of the wind noise to the audio signal, the low-pass reduction characteristic of the high-pass filter for reducing the wind noise is changed, so that good sound pickup quality and A sufficient wind noise suppression effect can be obtained at the same time. According to the invention, the high-pass filter
Consists of a plurality of filter circuits,
Selection of one filter circuit which substantially acts as a filter 16
Or control a combination of multiple filter circuits
In this way, it is possible to easily obtain appropriate shutoff characteristics.
Can be.

Further, according to the present invention, in the reproducing apparatus, it is possible to reduce the wind noise contained in the reproduced signal while minimizing the deterioration of the quality of the output audio signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a wind noise reduction device for facilitating understanding of the description of the present invention.

FIG. 2 is a diagram illustrating an example in which the high-pass filter of the example in FIG. 1 is configured by a primary IIR digital filter.

FIG. 3 is a diagram illustrating a frequency characteristic of the high-pass filter of the example of FIG. 1;

FIG. 4 is a diagram illustrating a relationship between a filter coefficient of the digital filter of FIG. 2 and a cutoff frequency.

FIG. 5 is a diagram illustrating an example of a power spectrum of wind noise.

FIG. 6 is a diagram illustrating an example of a power spectrum of an audio signal.

FIG. 7 is a diagram for explaining an input signal for an experiment of a reduction effect of the wind noise reduction device according to the present invention.

FIG. 8 is a diagram for explaining a reduction effect of the wind noise reduction device according to the present invention.

FIG. 9 is a diagram for explaining an input signal for an experiment of a reduction effect of the wind noise reduction device according to the present invention.

FIG. 10 is a diagram for explaining a reduction effect of the wind noise reduction device according to the present invention.

FIG. 11 is a diagram for explaining an input signal for an experiment of a reduction effect of the wind noise reduction device according to the present invention.

FIG. 12 is a diagram for explaining a reduction effect of the wind noise reduction device according to the present invention.

FIG. 13 shows a high-pass filter of the example of FIG.
It is a figure showing the example constituted by a digital filter.

14 is a diagram showing a relationship between a filter coefficient of the digital filter of FIG. 13 and a cutoff frequency.

FIG. 15 is a block diagram of one embodiment of a wind noise reduction device according to the present invention.

FIG. 16 is a block diagram of another embodiment of the wind noise reduction device according to the present invention.

FIG. 17 is a block diagram of another embodiment of the wind noise reduction device according to the present invention.

FIG. 18 is a block diagram of another embodiment of the wind noise reduction device according to the present invention.

[Explanation of symbols]

 11, 12 Microphone element 13, 14 A / D converter 15 Subtraction circuit 16 High-pass filter 17 D / A converter 18 Averaging circuit 19 Control circuit 20 Device output terminal

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kaoru Gyokudori Sony Corporation, 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo (56) References JP-A-5-14989 (JP, A) JP-A Heisei 4-363995 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 3/00 320 H03H 21/00 H04R 1/40 320

Claims (6)

(57) [Claims] A first and a second microphone element disposed close to each other; a wind noise detecting means for detecting a wind noise component by calculating a difference between outputs of the first and the second microphone elements; and a plurality of filters. It is configured to include a circuit,
It provided for the output signal of the first and / or second microphone devices, low frequency reduction characteristic variable high-pass filter, based on an output of the wind noise detector, the plurality of full
Selection of one of the filter circuits or
By controlling the combination of multiple filter circuits,
Ri, and control means for controlling the low-frequency reduction characteristic of the high-pass filter, wind noise reduction apparatus being characterized in that to obtain an audio output signal with reduced wind noise from the high-pass filter. 2. A two- channel signal from a recording medium in which signals obtained from first and second audio signals picked up by first and second microphone elements arranged close to each other are recorded as two channels. Means for reproducing; a high-pass filter provided with a variable low-frequency reduction characteristic for the reproduced audio signal; wind noise detecting means for detecting a wind noise component by calculating a difference between the reproduced signals; Control means for controlling the low-pass reduction characteristic of the high-pass filter based on the output of the means, wherein a wind noise-reduced audio output signal is obtained from the high-pass filter. 3. An audio signal obtained from the first and second audio signals picked up by the first and second microphone elements arranged close to each other, and the first and second audio signals. Means for reproducing a signal of a plurality of channels from a recording medium in which a wind noise signal obtained by a signal difference operation is recorded as a plurality of channels; and a low-frequency reduction characteristic provided for the reproduced audio signal is variable. A high-pass filter, and control means for controlling a low-frequency reduction characteristic of the high-pass filter based on the reproduced wind noise signal, wherein an audio output signal with reduced wind noise is obtained from the high-pass filter. Characteristic wind noise reduction device. 4. The wind noise reduction device according to claim 2, wherein the high-pass filter includes a plurality of filter circuits, and A wind noise reduction device wherein the control means controls the selection of one filter or the combination of a plurality of filter circuits which substantially acts as the high-pass filter. 5. The wind noise reduction device according to claim 2, wherein said high-pass filter is constituted by a digital filter, and a value of a filter coefficient is detected by said wind noise detection means. A wind noise reduction device adapted to be changed by the control means according to the level of noise. 6. The wind noise reduction device according to claim 2, wherein a high-pass filter different from the high-pass filter is provided for the reproduced audio signal. , The output of another high-pass filter above,
A wind noise reduction device, wherein a low-frequency reduction characteristic of the high-pass filter is controlled based on an output of the wind noise detection means.