JPH073745Y2 - Touch microphone - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is called a bone-conduction type microphone or the like that outputs a voice signal by contacting a pickup with the throat of a user to capture the vibration generated by the sound. With regard to the contact microphones, in particular, the voice signal representing the vibration due to the utterance and the noise signal representing the vibration due to the external noise added to the case are taken out separately, and the noise signal is erased to obtain only the voice signal. For contact microphones that we did tomorrow.

[Conventional technology]

A contact microphone that is attached so that the pickup touches the throat and ear canal of the user, captures vibrations due to vocalization, converts this to a voice signal and outputs it, cuts out noise and noise in the surrounding environment, and is attached. Since it is possible to extract only the voice of a person, it is becoming popular, for example, for communication at construction sites and microphones for motorcycle radio communication devices.

Such a contact microphone, as shown in FIG. 2 as an example, accommodates a plate-shaped piezoelectric element whose one end is supported in a cantilever manner by a damper 2 in a hollow case 1 and has one side surface of the case. It is configured by sticking a pickup 4 made of ABS resin or the like on. The vibration caused by the sound is captured by the entire case 1, and the vibration is converted into a sound electric signal by the piezoelectric element 3 which vibrates the internal piezoelectric element 3.
The output is output from the lead wire 5.
In order to reliably capture the vibration of the case 1, a weight 9 is attached to the other end of the piezoelectric element 3 so that the piezoelectric element 3 can be captured even with a slight vibration.

[Problems to be solved by the device]

However, the vibration caused by the sound is extremely small, and it is necessary to firmly attach the case 1 to the throat and temples of the wearer in order to reliably capture the minute vibration. As a result, the wearer feels too much pressure on the throat and ear canal, and the fit is poor. Further, since the vibration can be captured by the case 1 as a whole, high external noise may be captured by the case 1, which contributes to the utterance of noise.

Therefore, an object of the present invention is to provide a contact microphone that can accurately capture only vibration due to sound generation and that can be worn without causing discomfort to the wearer.

[Means for Solving the Problems]

This invention is a contact microphone that is mounted so as to contact with a part of the body, uses the pickup to capture the vibration caused by the sound, and outputs it as an audio signal with a conversion element, and converts the vibration of the pickup into an electrical signal and outputs it as an audio signal. A first conversion element, a second conversion element that converts the vibration of the case into an electric signal and outputs it as a noise signal, and a voice signal and a noise signal from the first and second conversion elements as inputs.
And a noise removing circuit that removes a noise signal component and outputs only a voice signal.

[Action]

With the configuration described above, the vibration captured by the pickup is converted into an audio signal by the first conversion element and applied to the noise canceling circuit. On the other hand, the vibration of the case due to external noise or the like is converted into a noise signal by the second conversion element and applied to the noise canceling circuit. In the noise cancellation circuit,
The noise signal is processed as a subtraction input of the voice signal, the noise signal is removed, and then the voice signal is output. Therefore,
The noise signal in the voice signal is removed, and the output signal from the noise canceling circuit is only the voice signal, and a voice signal without noise is obtained.

〔Example〕

An embodiment of the present invention shown in the drawings will be described below. In this embodiment, a throat-type contact microphone that is attached to the throat of the user is taken as an example. Touch microphone
The pickup 11 is made of metal or synthetic resin and is brought into contact with the throat of the user.
The same as the first conversion element 14 composed of a plate-shaped piezoelectric element for converting the vibrations of the above into an electric signal and the first conversion element 14 for converting the signal generated in the case 12 into an electric signal. And a conversion element 15.

The pickup 13 has a substantially T-shape as shown in FIG. 1, the horizontal portion thereof is brought into contact with the throat of the user, and the tip of this horizontally upright portion is the surface of the first conversion element 14. Is in contact with. The pickup 13 is supported by a damper 16 fitted in an opening 16 provided on one surface of the case 12 and made of an elastic material such as synthetic resin or rubber. The first and second conversion elements 14 and 15 are connected to the noise canceling circuit 21 via connection lines 18 and 19, respectively. This noise canceling circuit 21
The output signal from the first conversion element 14 is used as a normal input, the second conversion element 15 is used as a subtraction output, and the signal of the second conversion element 15 is removed and output to the connection line 22. This circuit is composed of a well-known arithmetic circuit and the like.

The contact microphone 11 configured as described above is attached so that the pickup 13 is brought into contact with the throat of the user. The signal from the throat that is produced by the user is picked up 13
It is captured by the first conversion element 14 via the, and converted into an electric signal and output to the noise canceling circuit 21 as an audio signal.
The vibration applied to the case 12 due to external noise or the like is converted into an electric signal by the second conversion element 15 and output to the noise canceling circuit 21. Since the noise canceling circuit 21 calculates a noise signal as a calculation signal, only a voice signal is output to the connection line 22. It should be noted that although the vibration is mainly detected by the second conversion element 15 due to the external noise added to the case 12, the vibration due to the noise attenuated by the damper 17 is also transmitted to the first conversion element 14 and is converted as a voice signal. However, the noise component in the audio signal can be removed by the noise canceling circuit 21.

Although the throat type contact microphone has been described in the above embodiments, it is needless to say that the present invention can be applied to an ear-insertion type contact microphone to be inserted into an ear canal.

[Effect of device]

As described above, the contact microphone of the present invention converts the vibration of the pickup into an electric signal and outputs the sound signal as the first conversion element, and the vibration due to the external noise added to the case converts the vibration into the electric signal. And having two conversion elements of a second conversion element that outputs as a noise signal,
Since the noise canceling circuit that removes only the noise signal component from the second conversion element is included, only a noise-free audio signal can be output. With this configuration, even if a noise component is mixed in the output signal of the first conversion element, it can be completely removed by the noise canceling circuit and only the audio signal can always be taken out, impairing the required frequency characteristic. It is possible to extract a clear audio signal without the need.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a vertical sectional view showing an example of a conventional contact microphone. In the drawing, 11 is a contact microphone, 12 is a case, and 13
Is a pickup, 14 is a first conversion element, 15 is a second conversion element, 17 is a damper, and 21 is a noise elimination circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Adachi 7-8 Sanbancho, Chiyoda-ku, Tokyo Yuasa Industrial Co., Ltd. (72) Inventor Mitsushi Takahashi 3-4-21 Owadacho, Hachioji-shi, Tokyo Stock company National Institute of Acoustics (56) Reference JP-A-59-86998 (JP, A) JP-A-58-80997 (JP, A) Practical application Sho-64-28085 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A contact microphone, which is mounted so as to contact with a part of a body, in which a vibration generated by a sound is captured by a pickup and is output as an audio signal by a conversion element, and the vibration of the pickup is converted into an electric signal. As a noise signal by converting the vibration of the case into an electric signal and outputting the noise signal as a noise signal, and the voice signal and the noise signal from the first and second conversion elements as inputs And a noise canceling circuit that removes the noise signal component and outputs only the audio signal.