摘要 |
PROBLEM TO BE SOLVED: To provide a transmission section with excellent sensitivity in which dispersion in the product is prevented by improving the work performance at assembling so as to keep airtightness of a rear exhaust chamber. SOLUTION: Holes 21a, 22a are made to a flip case 1a and a cover flop case 2a at positions opposite to a differential microphone 3 respectively, and a cylindrical rib 12a to which the differential microphone 3 is inserted to a rear side of the cover flip case 2a. A cable 5a connecting electrically to the differential microphone 3 is connected to the microphone holder 4a and its upper lower faces are formed to be a shape in close contact with the flip case 1a and the cover flip case 2a except a front chamber 14 and a rear chamber 16. Thus, other internal space of a transmission section is parted from th front chamber 14 and the rear chamber 16 of the differential microphone 3 and it is no possible that vibration such as the flip case 1a is resonated in the transmission section and picked up by the microphone 3 as noise.
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