| 摘要 |
PURPOSE:To catch a voice at the time of talking during a running with a satisfactory sensitivity ratio by burying two single directional microphone elements into the flexible polyurethane foam material of a continuous bubble structure to support the element. CONSTITUTION:The flexible polyurethane foam material 5 into which the microphone elements 1a, 1b are buried is sandwiching by a circuit substrate 7 and a screen 8 and supported. Thereby, the flexible polyurethane foam material 5 effectively sbsorbs noise by the vibration at the time of running of an automobile. The air conditioning wind of an air condition is prevented from abutting against the diaphragm of a microphone and being mixed as a wind noise. The flexible polyurethane foam material 5 may be preferable a non-combustible material, for instance, of density of 18-28 kg/m<3>, hardness of 3-13kg/314 cm<2>, repulsion resiliency of 35-45 %, compression resudual strain of 3-6 % and repeated compression residual strain of 2-6%.
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