VARIABLE DIRECTIONAL MICROPHONE UNIT AND VARIABLE DIRECTIONAL MICROPHONE

摘要

A variable directional microphone unit includes two capacitor elements. Each of the two capacitor elements has: a back plate formed on one side of an insulating plate to be insulated from a back plate of the other capacitor element; and a vibrating plate disposed to face the back plate with a certain amount of space therebetween, in which a polarization voltage is applied between each of the back plates and the vibrating plates so that an electroacoustically transduced signal is obtainable from each of the back plates. The variable directional microphone unit is characterized in that the two vibrating plates of the two capacitor elements are acoustically connected in series as a plurality of holes are formed on both of the back plates.