JPH074035B2 - Noise resistant microphone - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a microphone, and more particularly to a noise-resistant microphone capable of picking up only voice without being affected by external noise.

(Prior Art) A sound pressure type close-talking microphone is conventionally used as a microphone for removing the influence of external noise and picking up only voice.
There are bone conduction microphones such as a vibrating throat microphone, an ear bone microphone, or a nose bone microphone. However, these conventional sound pressure type microphones generally use a sound pressure type transducer having an impedance relatively close to the acoustic impedance of air, so that it is easy to pick up external noise and it is difficult for the listener to identify the voice. Moreover, bone conduction microphones such as ear bone microphones and nose bone microphones have a defect that S / N is likely to be picked up from the contact broadband noise generated by friction with the body surface when the body is moved. .

Further, when a wireless communication device using such a microphone and having an automatic transmission / reception switching function is used under high noise, the automatic switching function is apt to malfunction.

(Object of the Invention) The present invention has been made in order to eliminate the drawbacks of the conventional noise-lowering microphone as described above, and picks up only voice without being substantially affected by external noise and contact broadband noise. It is an object of the present invention to provide a noise resistant microphone that can be used.

(Summary of the Invention) In order to achieve the above-mentioned object, a noise-resistant microphone according to the present invention is configured such that a vibration-sensitive transducer is closely fixed to a sound-receiving block having an appropriate hardness to increase acoustic impedance. Is.

Embodiments of the Invention The present invention will be described in detail below based on the embodiments shown in the drawings.

FIG. 1 is a sectional view showing an embodiment of the noise resistant microphone according to the present invention.

In the figure, reference numeral 1 is a vibration-sensitive type transducer in which a transducer 4 using a piezoelectric element is sealed in a thin metal case 2 with a damper oil 3 applied in the direction of the arrow in the figure. The deformation of the piezoelectric element based on the generated vibration is converted into an electric signal. If the vibration propagating through the acrylic block 5 is detected by tightly fixing the transducer 1 to the hard acrylic block 5 with an adhesive 6 such as an epoxy resin, the acoustic impedance of such a microphone structure is Since it is extremely large (about 10 ⁶ times) compared to that of air, it is hardly affected by external noise.

In order to further eliminate the influence of external noise, the non-adhesive surface of the transducer 1 with respect to the acrylic block 5 may be covered with a sound absorbing material 7 such as silicone rubber or sponge as shown in FIG. It is effective.

The noise resistant microphone as described above is extremely effective when applied to, for example, a throat microphone.

FIG. 3 is a sectional view showing an embodiment of a throat microphone using the noise resistant microphone according to the present invention.

Since the throat microphone directly picks up the vibration of the throat accompanying the generation, the surface of the acrylic block 5 is exposed from the belt 8 so as to directly press the acrylic block 5 against the throat, and at the same time, the transducer 1 side is exposed. Is designed to be sealed with a resin film 9 which is a material of the belt 8 in consideration of waterproofness and the like. Incidentally, 10 is a pad for protecting the pharyngeal ridge, and the belt 8 has a stopper such as a buckle, but the illustration thereof is omitted to avoid complexity of the description.

Since the throat microphone having the configuration as described above is provided with microphones on both sides of the pharyngeal protuberance, any part of the sound receiving block 5 must be placed on the throat bone regardless of the posture of the attached object. Since the block 5 is pressed against the throat, the block 5 is less likely to rub against the throat, so that the voice can be picked up at a high level at all times with almost no contact broadband noise.

The above-mentioned transducer may be of any type as long as it is a vibration-sensitive type having a high acoustic impedance, and the material of the sound receiving block does not necessarily have to be acrylic, and it is not limited as long as it has a high acoustic impedance. Any material may be used.

(Advantages of the Invention) Since the present invention is configured as described above, its acoustic impedance is much higher than that of air, so that it is substantially insensitive to vibration propagating through air. Therefore, if it is applied to a wireless communication device used in a high noise level, it has a remarkable effect in removing noise and making a call with clear voice. Further, when the wireless communication device has a transmission / reception automatic switching function, it is possible to pick up a voice of a higher level than the noise from the outside world, so that it also has an effect of preventing its malfunction.

[Brief description of drawings]

1 and 2 are sectional views showing different configurations of the noise resistant microphone according to the present invention, and FIG. 3 is a partial sectional view showing the configuration of a throat microphone using the noise resistant microphone according to the present invention. is there. 1 ... Vibration-sensitive transducer, 5 ... Block, 7 ... Sound absorbing material.

Claims (2)

[Claims] 1. A bone-moving microphone that presses a vibration-sensitive transducer onto the surface of a living body to convert the vibration of the bone into an electrical signal, wherein the surface of the vibration-sensitive transducer case is pressed against the surface of the living body. A noise-resistant microphone characterized in that a block having a large acoustic impedance as compared with a hard and in-vitro acoustic medium is closely fixed. 2. A bone-moving microphone that presses a vibration-sensitive transducer onto the surface of a living body to convert the vibration of the bone into an electric signal, wherein the surface of the vibration-sensitive transducer case is pressed against the surface of the living body. Characterized in that a block having a large acoustic impedance as compared with a hard and in-vitro acoustic medium is closely fixed, and the back surface of the vibration-sensitive transducer structure tightly fixed to the block is covered with a sound absorbing material. Noise resistant microphone.