Patent ID: 8848950
Filing Date: 2014-09-30
Classification: H04R

Abstract:
1. A condenser microphone comprising: a plurality of electret condenser microphone units, each including a diaphragm and a fixed electrode opposing the diaphragm, one of the diaphragm and the fixed electrode having an electret layer thereon, one or more sensitivity controllers changing sensitivities of one or more units of the plurality of electret condenser microphone units, wherein the one or more sensitivity controllers include one or more variable resistors connected between a power source and a ground, there being for each unit of said plurality of electret condenser microphone units a respective variable resistor, wherein each of the one or more variable resistors has a slidable terminal connected to one of the diaphragm and the fixed electrode of the a corresponding condenser microphone unit such that the slidable terminal is opposing the electret layer of the corresponding condenser microphone unit, and wherein at least two variable resistors of said plurality of electret condenser microphone units are configured together as a double variable resistor and are connected to the power source in mutually opposite directions with respect to the ground.