close

Вход

Забыли?

вход по аккаунту

JP2005341360

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 JP2005341360
An object of the present invention is to provide a sound collection device capable of collecting a
sound signal desired to be collected, such as a voice emitted by a person under a noise
environment, by suppressing the noise. A sound collection object is brought into contact with a
sound collection object, and acoustic vibration is converted into an acoustic signal using a sound
collection sensor 4 by vibrating a diaphragm 2 through a housing upper part 1a. At that time,
external noise can be obtained by filling the case upper portion 1a with a medium having an
acoustic impedance value different from that of the medium through which external noise such
as liquid is transmitted and having an acoustic impedance value close to the medium through
which the sound collection object is transmitted. It is strong and has a good sound collection
efficiency. Further, by forming the sound insulating material 6 and the sound absorbing material
5 on the outer periphery and the inner periphery of the housing 1, it is difficult to transmit
external noise transmitted from other than the film body 3. [Selected figure] Figure 1
Sound collector
[0001]
The present invention relates to a sound collecting device for collecting and detecting sound
signals.
[0002]
Heretofore, it has been known that speech recognition used in a car navigation system etc. has a
low recognition rate due to the surrounding noise environment.
04-05-2019
1
For example, in addition to engine sounds of cars, wind noises and road noises, audio such as
radios and TVs to be viewed in a vehicle interior are noise sources when the user's voice is
recognized. In order to solve the problem, there has been proposed a technology for performing
speech recognition by detecting the user's bone conduction sound to distinguish it from
surrounding noise (see, for example, Patent Document 1). In Patent Document 1, sound vibration
due to bone conduction is transmitted to the bone around the ear canal, skin, a plastic member
for mounting on the ear canal, and a case for housing the detection element, and is transmitted to
the detection element of the beam structure via the support member. Be done. UnexaminedJapanese-Patent No. 2003-345381
[0003]
The above-described conventional configuration collects a sound signal generated by
transmitting a solid such as a plastic member, so the sensitivity largely changes depending on the
contact point with the human body, or the attachment point is limited by direct contact with
human skin. In addition, there is a problem that pain and discomfort remain in the user by
contacting with the bone, and the burden on the user is increased.
[0004]
An object of the present invention is to solve the above-mentioned conventional problems, and to
provide a sound collection device capable of collecting a sound signal desired to be collected
such as a voice emitted by a person under a noise environment by suppressing the noise.
[0005]
In order to solve the above-mentioned conventional problems, the sound collection device of the
present invention comprises a housing having an opening at one end, a diaphragm formed to
form a space with the inside of the housing at the other end, and a diaphragm And a film body
formed to cover the opening, and a medium made of a liquid that fills a space surrounded by the
housing, the film body, and the diaphragm.
[0006]
Further, the film body comes in contact with the human body, and the sensor detects the sound
vibration emitted from the human body by the vibration of the diaphragm through the medium.
[0007]
04-05-2019
2
Also, the housing may have a truncated conical or semi-elliptical sphere so that the surface area
of the membrane is greater than the surface area of the diaphragm.
[0008]
In addition, a sound insulating material and / or a sound absorbing material may be formed on
the outer wall of the housing.
[0009]
According to the sound collection device of the present invention, the inside of the case is filled
with the liquid, and the sound vibration of the medium can be detected to enhance the sound
collection effect of the sound vibration.
Further, by filling the inside of the case with the liquid and bringing the membrane into contact
with the human body, the adhesion to the sound collection target is increased unlike the solid,
and the sound collection efficiency is improved.
[0010]
Hereinafter, a sound collecting apparatus according to an embodiment of the present invention
will be described using the drawings.
[0011]
(Embodiment 1) The sound collection apparatus in embodiment of this invention is shown to
FIGS.
The sound signal collected in the first embodiment will be described by taking an example of a
voice emitted by a human.
[0012]
04-05-2019
3
FIG. 1 shows a longitudinal sectional view of a sound collecting apparatus according to an
embodiment of the present invention, FIGS. 2 (b) and 2 (c) show lateral sectional views, and FIG.
3 shows a perspective view.
A substantially frusto-conical case 1, a diaphragm 2 arranged so as to horizontally disassemble
the inside of the case 1 horizontally in the direction of the base, and an upper open end of the
case 1 are in contact with the human body , The sound collecting sensor 4 disposed on the
diaphragm 2, the sound absorbing material 5 and the sound insulating material 6 disposed on
the inner and outer circumferences of the housing 1, and the inner circumference of the housing
1 Space surrounded by the reverberation material 7, the vibration isolation material 8 disposed
at a position in contact with the diaphragm 2, the diaphragm 2, the film 3, the echo material 7,
and the vibration isolation material 8 ) Is constituted by the medium 9 to be filled.
The sound absorbing material 5 is disposed on the outer periphery of the housing 1 and the
sound insulating material 6 is disposed on the outer periphery thereof.
Here, assuming that the wide pedestal part is the upper housing part 1a, the narrow pedestal
part is the lower housing part 1b, the inside of the upper housing part 1a is the inside of the
housing 1c, and the inside of the lower housing part 1b is the inside of the housing 1d. The
sound insulating material 6 is disposed on the inner periphery of 1 b, and the sound absorbing
material 5 is disposed on the inner periphery thereof.
Further, the sound insulating material 6 is disposed on the inner periphery of the housing upper
portion 1a, and the reverberation material 7 is disposed on the inner periphery thereof.
However, at a portion in contact with the diaphragm 2, a vibration damping material 8 made of a
material different from that of the reverberation material 7 is disposed.
[0013]
Then, as a path of a sound signal when collecting sound, a sound signal is emitted from the
human body, and the diaphragm 2 is vibrated by passing from the film body 3 in contact with the
human body as a vibration through the medium 9 of the housing 1c. The sound collection sensor
4 takes a path of converting acoustic vibration into an electrical signal.
04-05-2019
4
[0014]
The medium 9 is made of liquid, and unlike the substance (usually air) outside the present sound
collector, the medium (usually a human body) to which the sound of the sound collection object
in contact with the film body 3 is transmitted and the acoustic impedance value It is desirable
that it be close and have a low sound attenuation rate.
About 80% of human components are water, which outputs acoustic vibration. Physiological
saline is used as the medium 9 to collect this acoustical vibration. This is because, as shown in
FIG. 4, when sound is collected in close contact with the human body, the acoustic impedance
value is very different when passing a gas such as air, so the acoustic impedance value should be
close to that of the human body. There is a need. It is considered appropriate that the acoustic
impedance value at this time is a liquid of about 1.3 to 2.0, and physiological saline was used as
an example. Further, as an effect of filling with a substance different from the external substance,
when acoustic vibration coming from the outside of the sound collection device is considered as
noise, the external noise is reflected by the film body 3 due to the difference in acoustic
impedance, and the sound collection efficiency is enhanced. It is to lead to a thing. One of the
reasons for using a liquid as the medium 9 is a damping rate. This is because it is possible to
increase the sound collection efficiency because the liquid differs by an order of 10 or more
compared to the attenuation factor of air.
[0015]
Next, in the housing upper portion 1a, the inner wall is surrounded by the reverberation material
7 whose acoustic impedance value is largely different from that of the medium 9 filled in the
housing interior 1c. Here, although the material of the reverberation material 7 is arbitrary, when
the acoustic impedance is largely different from that of the medium 9, the acoustic reflectance is
improved and the sound collection effect is enhanced. In the present embodiment, stainless steel
can be used as the reverberation material 7 in order to collect the sound of the human body.
[0016]
The following measures are taken against the noise transmitted from the case top 1a in the case
top 1a. Place porous material sponge, urethane, rock wool, glass wool, asbestos etc., perforated
plywood of perforated board, perforated gypsum board, perforated asbestos cement board etc. as
04-05-2019
5
sound absorbing material 5 on the outer wall of case 1 . For the material, any type can be used
according to the frequency to be absorbed. Moreover, a glass plate, a gypsum board, etc. are
arrange ¦ positioned as the sound insulation material 6 in the further outer periphery of the
sound absorption material 5. As shown in FIG. With regard to the material, any type can be used
according to the frequency of sound insulation. A material may be selected such that the
coincidence effect does not occur in consideration of the noise frequency from the outside.
Moreover, in the case of selection of the sound insulating material 6, the sound insulation effect
becomes high, so that a density is large. At this time, the combination of the sound absorbing
material 5 and the sound insulating material 6 is more effective for noise reduction, but either
one may be formed. In addition to the above, the outermost periphery of the housing 1 may be
made uneven to take measures against noise.
[0017]
Next, the diaphragm 2 forms a film by a member that responds to acoustic vibration such as a
plastic material. In addition to plastic materials, skin, metal, etc. may be arbitrarily selected
according to the frequency and sound pressure to be collected, and the tensile stress may be
arbitrarily changed.
[0018]
Further, in the present embodiment, a piezo sensor is used for the sound collection sensor 4 that
collects sound from the diaphragm 2. This is different from a condenser microphone or the like
against external noise, in order not to detect a direct sound from the air conduction sound, and is
configured to be strong against the air conduction noise. In addition, the housing upper portion
1a and the diaphragm 2 are surrounded by the sound insulation member 6 and the sound
absorption member 5, and in view of the difference in acoustic impedance value between the film
body 3 and the medium to which external acoustic vibration is transmitted The apparatus itself is
less likely to vibrate the diaphragm 2 with respect to external air conduction noise, and is
configured to be resistant to external air conduction noise. In addition, the attachment position of
the sound collection sensor 4 may be in contact with the diaphragm 2 on the housing interior 1 c
side or the housing interior 1 d side. However, when installed on the inside 1c side of the case,
the sound collection sensor 4 must be waterproofed. Any number of sound collection sensors 4
may be used according to the application.
[0019]
04-05-2019
6
In the method of attaching the sound collection sensor 4 to the diaphragm 2, one of the sound
collection sensors 4 is attached to the base where the diaphragm 2 is fixed to the lower part 1b,
and the other end is the center of the diaphragm 2 Attach to Thereby, one of the ends of the
sound collection sensor 4 is fixed, and the vibration of the diaphragm 2 is efficiently transmitted
to the sound collection sensor 4, so that an efficient sound collection effect can be expected.
Further, as shown in FIG. 2B, even if both ends of the sound collection sensor 4 are attached to
the lower part 1b of the case, the vibration of the diaphragm 2 can be efficiently transmitted to
the sound collection sensor 4.
[0020]
As the internal shape of the housing upper portion 1a, by using a truncated cone or an elliptical
sphere so that the surface area of the film body 3 is larger than the surface area of the
diaphragm 2, the sound collection effect is high. And since the attenuation of the acoustic
vibration is reduced by shortening the distance between the film body 3 and the diaphragm 2,
higher sound collection effect can be expected, but the film body 3 and the diaphragm 2 are in
physical contact Therefore, it is necessary to determine the optimal distance so that the
diaphragm 2 does not cause vibration due to interference.
[0021]
In the film body 3, the material can be arbitrarily selected according to the contact object, but in
the present embodiment, the thickness at the contact portion is preferably thin because of
contact with the human body, and the acoustic impedance value with the human body is close. Is
desirable. And, in order to improve the adhesion, it is desirable to use a material which can be
flexibly deformed and has a large frictional force. As an example, a low attenuation rubber for an
acoustic focal length adjustment spacer used for ultrasonic echo diagnosis and the like can be
mentioned.
[0022]
The material in the space surrounded by the lower part 1b and the diaphragm 2 is a gas, and a
sufficient volume is secured so that the pressure change of the lower part 1b does not affect the
04-05-2019
7
vibration of the diaphragm 2 when collecting sound. It has become. The inner wall of the lower
part 1b of the casing is installed with sound absorbing material 5 such as porous material
sponge, urethane, rock wool, glass wool, asbestos, etc., perforated plywood of perforated plate,
perforated gypsum board, perforated asbestos cement plate etc. Sound absorption. When sound
is collected by this sound absorbing material 5, the diaphragm 2 acts as a new sound source by
the vibration of the diaphragm 2, and is transmitted to the lower part 1b of the housing, and
acoustic vibration is reflected on the inner wall of the lower part 1b It is possible not to vibrate 2
again.
[0023]
A material (stainless steel in this case) whose acoustic impedance value differs greatly from the
medium 9 inside the case 1c is used as the reverberation material 7 on the inner wall of the
housing upper portion 1a, but this reverberation material 7 and the diaphragm 2 make contact
The vibration of the reverberation material 7 may be transmitted to the diaphragm 2 and the
diaphragm 2 may vibrate. Therefore, the vibration damping material 8 is installed between the
diaphragm 2 and the reverberation material 7 of the housing upper portion 1a to suppress the
propagation of the vibration of the reverberation material 7 to the diaphragm 2 as solid sound.
[0024]
In addition, in the membrane 3 and the housing upper portion 1a, the membrane 3 and the
periphery of the rim of the housing upper portion 1a are adhered with an adhesive or the like so
that the medium 9 (in this case, saline) is not leaked. Do. In addition, when the membrane body 3
is in contact with a human body or the like, since the outer periphery of the upper part 4 of the
housing is exposed, in order to optionally improve the protective material or the adhesion, a
material such as sponge or rubber is used. It is desirable to attach around the heel of the upper
body 1a.
[0025]
Second Embodiment In the second embodiment, an example of using the present sound
collection device in a vehicle compartment will be described with reference to FIG. When used in
the vehicle cabin in the present embodiment, the sound collector 100 is incorporated in and
attached to the seat 101. In that case, the membrane 3 comes in contact with the clothes of the
04-05-2019
8
human back. In addition, when fixing the sound collection device 100 to the seat 101, it is
necessary to connect the seat 101 and the sound collection device 100. Therefore, the seat 101
and the sound collector 100 are connected using a material that generates a restoring force due
to displacement of a position such as a spring, or a material whose reaction force changes in
proportion to the speed of a damper or the like to absorb impact force. The sound collecting
apparatus 100 is configured to robustly follow a human body in contact with the film body 3. In
the present embodiment, only the spring 103 is used. Further, in the present embodiment, by
fixing the spring 103 using the metal plate 104 fixed to the metal part attached to the seat 101,
it is possible to cope with the vertical displacement of the human back. There is.
[0026]
By using a vibration absorbing material or a damping material between the spring 103 and the
sound collecting device 100, the vibration of the diaphragm 2 due to the solid vibration
transmitted from the spring 103 can be further prevented.
[0027]
Further, in order to prevent interference between the seat 101 and the sound collecting device
100, a hole larger than the housing 1 of the sound collecting device 100 is required at the
mounting position of the seat 100.
Although the diameter of the hole is arbitrary, it is preferable to determine by measuring or
predicting the posture and the operating range when the target (the human body in this case) to
collect sound generates a sound signal.
[0028]
When sound vibration is not transmitted from the film body 3 to the diaphragm 2 because the
film body 3 completely contacts the human body and the human body interferes with external
noise, the sound pressure level collected by the sound collection sensor 4 is 40 dB or less is
desirable. This sound pressure level is a sound pressure level similar to that of a typical quiet
standard household, and is considered to be an environment suitable as a sound collection
environment. Here, the main noises in the vehicle compartment include road noise, audio
equipment such as music and radio, engine noise, and vibration of the vehicle body itself. The
frequency of each of these changes depending on the situation, but in the present embodiment,
04-05-2019
9
the frequency of road noise is 150 Hz to 500 Hz, the frequency flowing from audio equipment
such as music and radio is 800 Hz to 1.2 kHz, and the frequency of engine sound Is 400 Hz to
700 Hz. In this case, sound insulation must be performed for frequencies from approximately
150 Hz to 1.2 kHz, but when listening to the collected sound, non-stationary sounds as human
characteristics are very annoying and it is Since the process of separating it from the voice is also
difficult, this time, particularly the sound of the frequency of 800 Hz to 1.2 kHz flowing from
audio equipment such as music, radio and car navigation is isolated. Therefore, in order to set an
environment for collecting sound to 40 dB, a metal (such as iron) having a high density is used as
the sound insulating material 6 that performs sound insulation with respect to this frequency.
Moreover, although the sound absorbing material 5 is used as an intermediate material, the
sound transmission loss characteristic by the sound insulating material 6 is improved. Here, since
the combination of the sound insulating material 6 and the sound absorbing material 5 changes
depending on the structure and the like and quantitative prediction is difficult, the material of the
sound absorbing material 5 can not be determined generally, but glass wool is used this time.
The selection of the sound insulation 6 and the sound absorption 5 relates to the size of the
entire sound collection device. That is, the larger the sound collection device is, the larger the
housing is, and the larger the area in contact with the outside accordingly, so it is necessary to
make the sound insulation 6 thicker and to increase the sound transmission loss.
[0029]
In this device, not only the sound emitted from the human body by replacing the medium 9 filled
in the inside 1c of the case, but also using a sound collector used at the time of piping repair or
underwater by giving waterproofing it can. Further, it is possible to process voices collected by
the present sound collection device as speech segments and use them in voice recognition by
using in parallel with the air conduction microphone.
[0030]
As described above, the sound collection device according to the present invention has the effect
of being able to mechanically collect the sound signal of the sound collection target in the noise
environment, and is useful when it is desired to collect sound in a factory or car. It is.
[0031]
Cross-sectional view of the sound collecting apparatus in the longitudinal direction according to
the first embodiment of the present invention cross section for explaining the structure of the
sound collecting apparatus according to the first embodiment of the present invention
Perspective view of the sound collecting apparatus according to the first embodiment of the
04-05-2019
10
present invention Diagram showing acoustic impedance values and attenuation constants of
various materials Diagram showing an example when the sound collector of the second
embodiment of the present invention is attached to a seat
Explanation of sign
[0032]
DESCRIPTION OF SYMBOLS 1 housing ¦ casing part 1a housing ¦ casing upper part 1b housing ¦
casing lower part 1c housing ¦ casing inside 1d housing ¦ casing inside 2 diaphragm 3 film 4
sound collection sensor 5 sound absorbing material 6 sound insulating material 7 acoustic
material 8 anti-vibration material 100 sound collector 101 seat 103 Spring 104 metal plate
04-05-2019
11
1/--страниц
Пожаловаться на содержимое документа