Making the margin 1st process and on the aforementioned top face

摘要

PROBLEM TO BE SOLVED: To provide a sheet-like extended acoustic resistance material, a method for manufacturing the same, and a microphone unit capable of obtaining a stable acoustic resistance value without degrading directional frequency response.;SOLUTION: A sheet-like extended acoustic resistance material 21 is obtained by the following steps: a first step for selecting a sheet-like acoustic resistance material 22 determined based on a relation to a jig 11; a second step for applying tension in a state where the acoustic resistance material 22 is placed on the jig 11; a third step for selecting and arranging extension rings 25 adapting to the acoustic resistance material 22 in the state; a fourth step for joining the extension rings 25 to the acoustic resistance material 22; a fifth step for dismounting the acoustic resistance material 22 from the jig 11; and a sixth step for cutting peripheral parts 23 protruding from the extension rings 25. The sheet-like extended acoustic resistance material 21 covers through-holes in a microphone unit, so that a stable acoustic resistance value can be obtained without degrading directional frequency response.;COPYRIGHT: (C)2012,JPO&INPIT