Capacitive microphone having capability of acceleration noise cancelation

Abstract

The present invention provides a capacitive microphone having a capability of acceleration noise cancelation. The microphone includes (1) a moveable functional membrane comprising a basic functional membrane with an area Ao; and (2) a moveable reference membrane comprising a basic reference membrane. The basic reference membrane has one or more holes through the membrane's thickness, and the moveable reference membrane would be identical to the moveable functional membrane if the basic reference membrane does not have said one or more holes. The total area of said one or more holes is Ah, and a hole density HD is defined as Ah/Ao (%), and HD is in the range of e.g. from 0.012% to 2.647%.

Dependencies are inferred from the claim text.