| 摘要 |
PURPOSE:To output an audio signal of good S/N without an influence of whistling or the like by separating the inside and the outside by a vessel which is made of a sound shielding material and is closely brought into contact with a wall surface and setting microphones on the inside and the outside of this vessel. CONSTITUTION:A vessel 9 is fixed to a front glass 4 with an adhesive rubber 11 by an adhesive. A microphone 1 is fixed to the inside of the vessel 9, namely, the side facing the front glass 4 with an adhesive between them by a fixing rubber 1a, and a microphone 2 is fixed to the outside of the vessel 9, namely, the surface on the side of a driver 6 with an adhesive between them by a fixing rubber 2a, and a space part is formed in the vessel 9. Cables led out from microphones 1 and 2 are connected to a connector, and output signals T and P of microphones 1 and 2 are inputted to a synthesizing circuit 3. Thus, the noise suppressing capability is improved even in circumstances where exposed to wind pressure. |
