Patent ID: 8325960
Filing Date: 2012-12-04
Classification: H04R

Abstract:
1. A narrow directional microphone comprising: an acoustic tube having a front end opened as a front sound wave introduction port, a side sound wave introduction port in a tube peripheral surface thereof, and a rear sound wave introduction port on a rear end side; a unidirectional condenser microphone unit disposed between the side sound wave introduction port and the rear sound wave introduction port in the acoustic tube; and a cylindrical microphone casing which is larger in diameter and longer than the acoustic tube, having an opening in a portion corresponding to the side sound wave introduction port and the rear sound wave introduction port, and arranged so as to cover the acoustic tube, wherein the acoustic tube includes a cylindrical body formed of a rounded flexible sheet, and having a large number of pores formed in the sheet at at least the side sound wave introduction port; and the sheet is a metal sheet, and the large number of pores having pore diameters and pitches substantially equal.