| 摘要 |
PROBLEM TO BE SOLVED: To provide a unidirectional cylindrical condenser microphone unit capable of preventing cavity resonance by using a filling member functioning as an acoustic resistor.SOLUTION: The unidirectional cylindrical condenser microphone unit 11 includes: a cylindrical body 52 including an electronic circuit member side held by a holding member 64 on a rear position of a rear acoustic terminal 54 formed on a front end part 53; a condenser microphone unit 57 having a front acoustic terminal 58 on a top end surface 57a and detachably attached to the front end side of the cylindrical body 52; and a filling member 12 filled in a cavity 55 secured in the front end part 53 of the cylindrical body 52 through the holding member 64 and supported by the holding member 64. The filling member 12 is formed by a plastic sintered porous body 13 having many continuous pores and the continuous pores function as acoustic resistance holes permitting the transmission of sound waves to prevent the generation of cavity resonance. |
