close

Вход

Забыли?

вход по аккаунту

?

JP2010050500

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2010050500
The present invention provides a back noise suppression microphone that suppresses back noise
over a wide frequency range. A back noise suppression microphone (1) is provided with a
superdirective microphone (2) having superdirectivity, and a plurality of unidirectional
microphones (4) directed at the back direction of the single directivity microphone (4). A
microphone array 3 for outputting a signal, a microphone array signal subtraction means 11 for
subtracting a signal output from a pair of unidirectional microphones 4 set in advance, and a
microphone array signal subtraction means 11 Microphone array signal shaping means 12 for
shaping the signal in accordance with the frequency component of the back noise, and
superdirectional microphone signal subtraction for subtracting the signal shaped by the
microphone array signal shaping means 12 from the signal output from the superdirectional
microphone 2 And means 13. [Selected figure] Figure 4
Rear noise suppression microphone
[0001]
The present invention relates to a back noise suppression microphone that picks up a target
sound from the front direction and suppresses back noise that is an unintended sound from the
back direction.
[0002]
Conventionally, when picking up outdoors, it is difficult to cope with all situations with one kind
of microphone, so various types having directional characteristics such as omnidirectionality,
04-05-2019
1
unidirectionality, superdirectivity, etc. Microphones have been developed for different
applications.
Here, when using a microphone outdoors, it is rare that there is no sound other than the target
sound. For this reason, in outdoor sound collection, a shotgun microphone is widely used for the
purpose of suppressing noise from the side surface using a long acoustic tube and collecting
sound from the front direction (target sound). (For example, product manufactured by Sennheiser
Japan Ltd., product name: MKH-416, MKH-816).
[0003]
In addition, in order to suppress unintended sound from the back direction (back noise), a small
narrow-angle directional microphone is known in which a superdirective microphone and a
secondary sound pressure gradient microphone in the back direction are combined (see For
example, refer to Patent Document 1). JP 2005-323157 A
[0004]
However, although the shotgun microphone described above can suppress non-target sound
from the side direction, it can not suppress non-target sound from the back direction (back
noise), and the sound collection and relay of sports relay avoiding the gallery It is not suitable for
sound collection from the car. Furthermore, since the noise generated by the user of the shotgun
microphone is generated in the back direction of the shotgun microphone, there is a problem
that the shotgun microphone also picks up the noise.
[0005]
Also, although the above-described small narrow-angle directional microphone aims to suppress
unintended sound from the rear direction, the middle low-pitch range is targeted, so for example,
the rear side with many high frequency components such as clapping. There is a problem that
noise can not be sufficiently suppressed.
[0006]
Therefore, an object of the present invention is to provide a back noise suppression microphone
that suppresses back noise over a wide frequency range.
04-05-2019
2
[0007]
In order to solve the problems described above, the back noise suppression microphone
according to claim 1 is a back noise suppression microphone that picks up a target sound from
the front direction and suppresses back noise that is an unintended sound from the back
direction. A superdirective microphone having superdirectivity as a directional characteristic,
picking up sound from the front direction and outputting a signal, and a unidirectional
microphone having unidirectionality as a directional characteristic A plurality of microphone
arrays arranged at predetermined intervals toward the rear direction, collecting the rear surface
noise and outputting a signal, a microphone array signal subtraction unit, a microphone array
signal shaping unit, and a superdirective microphone signal subtraction unit And.
[0008]
In such a configuration, the back noise suppression microphone picks up the sound from the
front, that is, the target sound generated by the object, by the superdirective microphone.
At this time, the back noise suppression microphone picks up back noise exhibiting a frequency
characteristic in which peaks and valleys are continuous due to the back characteristic of the
superdirective microphone.
In addition, the back noise suppression microphone picks up back noise that is an unintended
sound by the microphone array.
In addition, the non-target sound is various noises generated by other than the target.
[0009]
Also, the back noise suppression microphone subtracts the signals output from a pair of
unidirectional microphones set in advance in the microphone array by the microphone array
signal subtraction means. Here, the frequency range of back noise that can be suppressed differs
depending on the spacing at which the unidirectional microphones are arranged. That is, in the
back noise suppression microphone, a pair of unidirectional microphones that subtract a signal is
04-05-2019
3
set in advance so that back noise can be suppressed.
[0010]
Also, the back noise suppression microphone shapes the signal subtracted by the microphone
array signal subtraction means by the microphone array signal shaping means in accordance
with the frequency component in the back direction of the superdirective microphone. Here,
since the back noise suppression microphone becomes a wave having a continuous frequency
characteristic of the back noise by the microphone array signal shaping means, it shapes the
signal subtracted by the microphone array signal subtraction means according to the waveform
of each wave. . And a back noise suppression microphone subtracts the signal which microphone
array signal shaping means shaped, ie, back noise, from the signal which a super directional
microphone outputs with a super directional microphone signal subtraction means.
[0011]
A back noise suppression microphone according to claim 2 is the back noise suppression
microphone according to claim 1, wherein the unidirectional microphones of the microphone
array are directed to the front direction bordering on an acoustic center of the superdirective
microphone. And the microphone array signal subtraction means are disposed in the back
direction respectively, and the microphone array signal subtraction means is equidistant from the
acoustic center as the frequency component of the back noise becomes lower and is spaced apart
from each other. The signals output from the acoustic microphones are subtracted, and the
higher the frequency component of the back noise is, the equidistant distance from the acoustic
center and the signals output from the pair of unidirectional microphones arranged closer to
each other It is characterized by subtracting.
[0012]
In such a configuration, since the back noise suppression microphone is based on the acoustic
center by the microphone array signal subtracting means, the occurrence of the phase shift can
be prevented.
[0013]
A back noise suppression microphone according to claim 3 is the back noise suppression
microphone according to claim 1 or 2, wherein the microphone array signal subtraction means
has the same number as the number of combined unidirectional microphones. A subtractor
subtracts a signal output from the unidirectional microphone, and the microphone array signal
04-05-2019
4
shaping means passes a low-pass filter that passes frequency components lower than a preset
frequency, and a frequency higher than the preset frequency. It is characterized in that the signal
subtracted by the microphone array signal subtracting means is shaped by a high pass filter
which passes the component.
[0014]
In such a configuration, the back noise suppression microphone can simplify the microphone
array signal subtracting means and the microphone array signal shaping means.
[0015]
According to the present invention, the following excellent effects can be obtained.
According to the invention of claim 1, each signal of the output of the unidirectional microphone
which can pick up the back noise is subtracted, and each of the back characteristics of the
superdirective microphone for the front direction which becomes a peak and valley where the
frequency characteristics are continuous. By shaping this signal in accordance with the waveform
of the wave, the sensitivity to the sound from the back direction can be suppressed and noise can
be reduced over a wide frequency range.
[0016]
According to the second aspect of the invention, the occurrence of the phase shift can be
prevented, so that the situation where the back noise can not be suppressed can be prevented.
According to the third aspect of the present invention, the back noise suppression microphone
can be simplified.
[0017]
Hereinafter, embodiments of the present invention will be described in detail with reference to
the drawings.
04-05-2019
5
In each of the embodiments, means and members having the same function are denoted by the
same reference numerals, and the description thereof is omitted.
[0018]
[Configuration of Rear Noise Suppression Microphone] The configuration of the rear noise
suppression microphone according to the embodiment of the present invention will be described
below with reference to FIGS. 1 and 2.
FIG. 1 is an external view of a back noise suppression microphone according to an embodiment
of the present invention. FIG. 2 is a schematic view schematically showing the back noise
suppression microphone according to the embodiment of the present invention. The back noise
suppression microphone 1 of FIG. 1 is for picking up sound from the front direction and
suppressing back noise which is noise from the back direction, and includes a superdirective
microphone 2 and a microphone array 3; And control means 10. Further, in FIG. 2, the right side
of FIG. 2 is referred to as the front (front direction), and the left side of FIG. 2 is referred to as the
back (back direction).
[0019]
The superdirective microphone 2 has superdirectivity as directivity characteristics, picks up the
sound from the front direction and the back noise, and outputs a signal. For example, the
vibrating membrane 2b is formed at the inner left end of the acoustic tube 2a. Are arranged.
Here, as the superdirective microphone 2, for example, there is a dynamic microphone having
superdirectivity or a condenser microphone having superdirectivity.
[0020]
The acoustic tube 2a is a hollow cylindrical body having a length of, for example, about 30 cm, in
which slits or continuous holes (not shown) for suppressing side incoming noise are formed on
the side surfaces. The vibrating film 2b is disposed at the inner left end of the acoustic tube 2a
and captures air vibration, and is, for example, a metal film such as aluminum or germalmin, or a
04-05-2019
6
synthetic resin film such as polyethylene terephthalate. Further, the vibration of the vibrating
membrane 2 b is converted into an electric signal by a sensor (not shown) and output to the
control means 10. The acoustic center 2c is at the central position in the longitudinal direction
(front direction to back direction) of the acoustic tube 2a.
[0021]
The cover 2d accommodates and protects the acoustic tube 2a, the diaphragm 2b, the
microphone array 3 described later, and the control means 10 described later. As shown in FIG.
1, the cover 2d has a cylindrical shape whose diameter in the front direction is the same as the
diameter in the back direction, and a sound wave incident port is formed in the front of the front
direction and a slit is formed in the side. There is. In FIG. 1, the acoustic tube 2a, the diaphragm
2b, the unidirectional microphone 4 and the control means 10 are not shown because they are
accommodated in the cover 2d.
[0022]
Here, the superdirectivity is obtained by further narrowing the single directivity which is a
directivity characteristic that is easy to catch the sound in the front direction. FIG. 3 is a view
showing an example of polar patterns of the superdirective microphone of FIG. In FIG. 3, 0 °
corresponds to the front of FIG. 2, and 180 ° corresponds to the back of FIG.
[0023]
The superdirective microphone 2 has strong directivity in the range of about 60 ° centered on
the front direction (0 °) as shown in FIG. For this reason, the superdirective microphone 2
hardly picks up noise from the side direction (90 °, 270 °). However, as shown in FIG. 2, the
superdirective microphone 2 also has sensitivity in the back direction (180 °). That is, the
superdirective microphone 2 picks up the back noise due to the sensitivity in the back direction.
[0024]
The microphone array 3 shown in FIG. 2 is configured such that n singlets of which polarity is
04-05-2019
7
reversed so that n single directional microphones 41, 4l, 4m, 4n (where 2 ≦ l ≦ m ≦ n) become
differential. One directional microphones 41 to 4 n (secondary sound pressure tendency
microphones) are disposed at a predetermined interval (for example, 4.25 cm). When the
unidirectional microphones 41 to 4 n are described without distinction, they are simply referred
to as the unidirectional microphone 4.
[0025]
Further, in the microphone array 3, n single directional microphones 4 are arranged in the front
direction and the rear direction with the acoustic center 2 c of the superdirective microphone 2
as a boundary. Then, the microphone array 3 converts the sound collected by the unidirectional
microphone 4 into an electric signal and outputs the electric signal to the control means 10.
[0026]
As shown in FIG. 4, the unidirectional microphone 4 has unidirectionality as a directional
characteristic, and is, for example, a microphone with a small diaphragm. FIG. 4 is a diagram
showing an example of polar patterns of the unidirectional microphone of FIG. In FIG. 4, 0 °
corresponds to the front of FIG. 2 and 180 ° corresponds to the back of FIG. 2.
[0027]
In practice, the unidirectional microphone 4 is disposed with the sound receiving surface (not
shown) of the unidirectional microphone 4 directed to the back surface of the superdirective
microphone 2. Therefore, the unidirectional microphone 4 picks up sound from the back
direction (180 °), that is, back noise.
[0028]
Here, the back noise suppression microphone 1 is used differentially by combining two
unidirectional microphones 4, that is, it is used as a secondary sound pressure gradient
microphone. FIG. 5 is a view showing an example of a polar pattern of a secondary sound
pressure gradient microphone combining the pair of unidirectional microphones 4 of FIG. In FIG.
04-05-2019
8
5, 0 ° corresponds to the front of FIG. 2, and 180 ° corresponds to the back of FIG.
[0029]
As shown in FIG. 5, the secondary sound pressure gradient microphones (a pair of unidirectional
microphones 4) have directivity in the front direction (0 °) and have almost no sensitivity in the
rear direction. Therefore, the secondary sound pressure gradient microphone can effectively
collect only the back noise. The relationship between the spacing of the unidirectional
microphone 4 and the frequency characteristic will be described later.
[0030]
The control means 10 of FIG. 2 controls the back noise suppression microphone 1. The
configuration of the control means 10 will be described below with reference to FIG. FIG. 5 is a
block diagram showing the configuration of the control means of FIG.
[0031]
<Configuration of Control Unit of Rear Noise Suppression Microphone> As shown in FIG. 6, the
control unit 10 includes a microphone array signal subtracting unit 11, a microphone array
signal shaping unit 12, and a superdirectional microphone signal subtracting unit 13. .
[0032]
The microphone array signal subtraction means 11 subtracts signals output from a pair of
unidirectional microphones 4 (2 ≦ j ≦ k ≦ 1 ≦ m ≦ n) set in advance in the microphone array
3. is there.
For example, in FIG. 6, the first subtraction unit 11a that subtracts the signal output from the
unidirectional microphone 4n from the signal output from the unidirectional microphone 41 and
the signal output from the unidirectional microphone 4j The second subtraction unit 11a that
subtracts the signal output from the unidirectional microphone 4m, and the third subtract the
signal output from the unidirectional microphone 4l from the signal output from the
unidirectional microphone 4k Although the subtraction unit 11a is illustrated, the number of
04-05-2019
9
subtraction units 11a is not limited thereto. For example, when the number of unidirectional
microphones 4 is n, the maximum number of subtraction units 11 a is a number obtained by
combining n (not shown).
[0033]
Here, the microphone array signal subtraction means 11 subtracts the signals outputted by the
pair of unidirectional microphones 4 arranged at an interval that can suppress the back noise by
the subtraction unit 11 a. For example, as the frequency component of the back noise becomes
lower (for example, the sound of the drum of a cheering party in sports relay), the microphone
array signal subtraction means 11 is a pair equidistant from the acoustic center 2c and disposed
apart from each other. The signals output from the unidirectional microphones 41 and 4 n are
subtracted.
[0034]
Also, for example, as the frequency component of the back noise becomes higher (for example,
the sound of a clap in sports relay) by the subtractor 11a, the microphone array signal
subtraction means 11 is equidistant from the acoustic center 2c and closer to each other. The
signals output from the pair of unidirectional microphones 4l and 4m arranged are subtracted.
[0035]
Then, the microphone array signal subtraction unit 11 outputs the subtracted signal to the
microphone array signal shaping unit 12.
For example, when the pair of unidirectional microphones 41 and 4 n are set in advance, the
microphone array signal subtracting unit 11 is a unidirectional microphone 41 by the
subtraction unit 11 a connected to the unidirectional microphones 41 and 4 n. The signal output
by the unidirectional microphone 4 n is subtracted from the signal output by
[0036]
The microphone array signal shaping means 12 shapes the signal subtracted by the microphone
04-05-2019
10
array signal subtraction means 11 in accordance with the frequency component of the back
noise. Also, the microphone array signal shaping means 12 measures the sensitivity of each
unidirectional microphone 4 in advance, and on the basis of this sensitivity, the sensitivity of the
signal processed by the LPF 12a and the HPF 12b is substantially the same as that of the back
noise. You may adjust the level to be Further, the microphone array signal shaping means 12
outputs the shaped signal to the superdirective microphone signal subtraction means 13.
[0037]
Further, the microphone array signal shaping means 12 can be configured by combining an LPF
(low pass filter) 12 a and an HPF (high pass filter) 12 b so as to correspond to each of the
subtraction units 11 a. For example, although FIG. 6 illustrates three sets of the LPF 12a and the
HPF 12b, the present invention is not limited to this. For example, the microphone array signal
shaping unit 12 can be configured by combining the LPF 12 a and the HPF 12 b in the same
number as the subtraction unit 11 a. The details of signal shaping by the microphone array
signal shaping means 12 will be described later.
[0038]
The superdirective microphone signal subtraction means 13 subtracts the signal shaped by the
microphone array signal shaping means 12 from the signal output from the superdirective
microphone 2. Here, in order to subtract the signal shaped in accordance with the back noise
from the signal output from the superdirective microphone 2, the superdirective microphone
signal subtraction means 13 outputs the back noise included in the signal output from the
superdirective microphone 2. Can be suppressed.
[0039]
The control means 10 may further include an amplifier, and the amplifier may amplify the signal
output from the superdirective microphone signal subtraction means 13 (not shown). In this
case, the control means 10 may perform the above-mentioned level adjustment after amplifying
the signal by the amplifier.
[0040]
04-05-2019
11
<Details of Signal Shaping> Hereinafter, the details of the signal shaping by the microphone array
signal shaping means 12 of FIG. 6 will be described with reference to FIGS. 7 and 8 (see FIGS. 2
and 6 as needed). FIG. 7 is a view for explaining the details of signal shaping by the microphone
array signal shaping means of FIG. 6, where (a) is a view showing an example of the frequency
characteristic of the back noise collected by the superdirective microphone; b) is a figure which
extracted the wave to the 1st dip, (c) is a figure which extracted the wave from the 1st dip to the
2nd dip. In FIGS. 7 and 8, the horizontal axis represents frequency (Hz) and the vertical axis
represents sensitivity (dB).
[0041]
As shown in FIG. 7 (a), the superdirective microphone 2 picks up a back noise that is similar to a
comb filter and shows a frequency characteristic with continuous peaks and valleys. Here, when
the length of the acoustic tube 2a is L, dips occur at frequency intervals that satisfy the equation
(1). The dip indicates that the sensitivity drops sharply at a certain frequency, and is illustrated as
a valley in FIGS. 7 and 8. In equation (1), λ indicates the wavelength of the back noise. Formula
(1): L = λ / 2, λ.
[0042]
Since this dip occurs at the above-described frequency interval, the superdirective microphone 2
picks up sound as back noise showing a frequency characteristic in which peaks and valleys are
continuous. Thus, in the back noise, since the peaks and valleys exhibit a continuous frequency
characteristic, the prior art can suppress the back noise only up to the first dip as shown in FIG.
7B, and the effect is insufficient. It is thought that there was. Therefore, as shown in FIG. 7A, the
present invention effectively suppresses the back noise by dividing the back noise showing the
frequency characteristic in which the peaks and valleys are continuous by the dip and treating
the back noise as individual peaks and valleys. It made it possible.
[0043]
For example, the back noise in FIG. 7 (a), the peak to the first dip in FIG. 7 (b), the peak from the
first dip to the second dip in FIG. 7 (c), and the illustration are omitted. The peaks from the
04-05-2019
12
second dip to the third dip and the peaks (x is the number of dips) from the x-1st dip to the x-th
dip (not shown) are handled separately. Hereinafter, an example in which a peak from the first
dip to the second dip in FIG. 7C among the back noise in FIG. 7A is suppressed as the back noise
will be described.
[0044]
FIG. 8 is a view for explaining the details of signal shaping by the microphone array signal
shaping means 12 of FIG. 6, and (a) shows an example of the frequency characteristic of a signal
obtained by subtracting the outputs of a pair of unidirectional microphones. (B) is a figure which
shows the example of the frequency characteristic of the signal which the microphone array
signal shaping means shaped. Here, as shown in FIG. 8A, even in the signal from which the
outputs of the pair of unidirectional microphones 4 are subtracted, dips occur at different
frequency intervals according to the distance between the pair of unidirectional microphones 4.
Occur. Therefore, a pair of unidirectional microphones 4 in which dips occur at substantially the
same frequency intervals as in FIG. 7C are set in advance, and the microphone array signal
subtracting means 11 outputs these unidirectional microphones 4. Subtract the signal.
Hereinafter, an example in which the microphone array signal subtraction unit 11 outputs a
signal having the frequency characteristic shown in FIG. 8A to the microphone array signal
shaping unit 12 will be described.
[0045]
The microphone array signal shaping means 12 shapes the signal output from the microphone
array signal subtraction means 11, here the signal of FIG. 8A, to substantially the same frequency
characteristic as the back noise of FIG. 7C. Specifically, the microphone array signal shaping
means 12 cuts the frequency region higher than the frequency at which the second dip occurs by
the LPF 12a. Then, the microphone array signal shaping means 12 cuts the frequency region
equal to or lower than the frequency at which the first dip is generated by the HPF 12 b.
Furthermore, the microphone array signal shaping means 12 increases / decreases the signal of
which the frequency region is cut to almost the same sensitivity as the back noise in FIG. 7C
(level adjustment). Then, the microphone array signal shaping means 12 outputs the shaped
signal to the superdirective microphone signal subtraction means 13.
[0046]
04-05-2019
13
Although the example in which the peaks from the first dip to the second dip in FIG. 7C are
suppressed as the back noise has been described, the peaks from the second dip to the third dip,
the x-1st The mountain from the dip of x to the dip of x th is also suppressed as the back noise.
In this case, the back noise suppression microphone 1 has a pair of unidirectionality so as to
correspond to the peaks from the second dip to the third dip and the peaks from the x-1st dip to
the xth dip. The microphones 4 are respectively set.
[0047]
<Relationship between Spacing of Unidirectional Microphone 4 and Frequency Characteristic>
The relationship between spacing of the unidirectional microphone 4 of FIG. 2 and frequency
characteristic will be described below with reference to FIG. See Figure 6). FIG. 9 is a diagram
showing an example of frequency characteristics of a signal obtained by subtracting the outputs
of a pair of unidirectional microphones. In FIG. 9, the horizontal axis is frequency (Hz) and the
vertical axis is sensitivity (dB).
[0048]
As described above, the back noise suppression microphone 1 subtracts the signals output from
the pair of unidirectional microphones 4. Here, assuming that the distance between the
unidirectional microphones 4 is D, the peak frequency fp at which the sensitivity is highest can
be represented as 340 / 2D in the signal of the frequency characteristic as shown in FIG. The
frequency fd can be expressed as 340 / D. For example, when the distance D of the unidirectional
microphones 4 is 10 cm, the peak frequency fp is 1.7 kHz and the dip frequency fd is 3.4 kHz.
[0049]
Further, for example, in the frequency characteristics of the superdirective microphone 2, a case
where the peak frequency fp is 2 kHz and the dip frequency fd is 4 kHz will be considered. In this
case, in order to suppress the back noise, the unidirectional microphones 4 in which the spacing
D of the unidirectional microphones 4 is 8.5 cm and 4.25 cm are preset, and the microphone
array signal shaping means 12 The signal output from the unidirectional microphone 4 is
subtracted.
04-05-2019
14
[0050]
[Operation of Control Unit of Rear Noise Suppression Microphone] Hereinafter, the operation of
the control unit 10 of FIG. 6 will be described with reference to FIG. 10 (see FIG. 4 as needed).
FIG. 10 is a flow chart showing the operation of the control means of FIG.
[0051]
First, the back noise suppression microphone 1 subtracts the signals output from the pair of
unidirectional microphones 4 set in advance in the microphone array 3 by the microphone array
signal subtraction means 11. Here, as the frequency component of the back noise becomes lower
by the microphone array signal subtraction means 11, the back noise suppression microphone 1
is equidistant from the acoustic center 2c and is spaced apart from each other as a pair of single
directivity The signal output from the microphone 4 is subtracted, and the higher the frequency
component of the back noise, the equal distance from the acoustic center 2c and the signals
output from a pair of unidirectional microphones 4 arranged closer to each other (Step S11).
[0052]
Following the process of step S11, the back noise suppression microphone 1 shapes the signal
subtracted by the microphone array signal subtraction means 11 by the microphone array signal
shaping means 12 in accordance with the frequency component of the back noise. Here, the back
noise suppression microphone 1 performs a convolution operation of the LPF 12a and the HPF
12b by the microphone array signal shaping unit 12, and shapes the signal subtracted by the
microphone array signal subtraction unit 11 (step S12).
[0053]
Subsequent to the process of step S12, the microphone array signal shaping unit 12 shapes the
level of the back noise suppression microphone 1 by the superdirective microphone signal
subtraction unit 13 from the signal output from the superdirective microphone 2 and performs
level adjustment. The signal is subtracted (step S13). As described above, the back noise
suppression microphone 1 can suppress back noise over a wide frequency range.
04-05-2019
15
[0054]
Since the back noise suppression microphone according to the embodiment of the present
invention suppresses the back noise over a wide frequency range, it is possible to easily pick up
the sound outside which was conventionally difficult. Furthermore, the back noise suppression
microphone according to the embodiment of the present invention can efficiently separate and
collect the sound of each instrument in an environment in which sound sources are dense, for
example, installation in an orchestra.
[0055]
It is an outline view of a back noise suppression microphone concerning an embodiment of the
present invention. FIG. 1 is a schematic view schematically showing a back noise suppression
microphone according to an embodiment of the present invention. It is a figure which shows the
example of the polar pattern of the super-directional microphone of FIG. It is a figure which
shows the example of the polar pattern of the unidirectional microphone of FIG. It is a figure
which shows the example of the polar pattern of the secondary sound pressure gradient
microphone which combined a pair of unidirectional microphones 4 of FIG. It is a block diagram
which shows the structure of the control means of FIG. It is a figure explaining the detail of signal
shaping by the microphone array signal shaping means of FIG. 6, (a) is a figure showing an
example of the frequency characteristic of back noise which a superdirectional microphone
collected, (b) is 1 It is a figure which extracted the mountain to the 2nd dip, and (c) is a figure
which extracted the mountain from the 1st dip to the 2nd dip. FIG. 7 is a diagram for explaining
the details of signal shaping by the microphone array signal shaping means 12 of FIG. 6, in which
(a) is a diagram showing an example of frequency characteristics of a signal obtained by
subtracting the outputs of a pair of unidirectional microphones; b) is a figure which shows the
example of the frequency characteristic of the signal which the microphone array signal shaping
means shaped. It is a figure which shows the example of the frequency characteristic of the
signal which subtracted the output of a pair of unidirectional microphones. It is a flowchart
which shows operation | movement of the control means of FIG.
Explanation of sign
[0056]
04-05-2019
16
1 back noise suppression microphone 2 super directional microphone 2a acoustic tube 2b
diaphragm 2c acoustic center 2d cover 3 microphone array 4 unidirectional microphone 41
single directional microphone 4 l single directional microphone 4 m single directional
microphone 4 n single Unidirectional microphone 10 Control means 11 Microphone array signal
subtraction means 12 Microphone array signal shaping means 13 Superdirective microphone
signal subtraction means
04-05-2019
17
Документ
Категория
Без категории
Просмотров
0
Размер файла
28 Кб
Теги
jp2010050500
1/--страниц
Пожаловаться на содержимое документа