SINGLE DIAPHRAGM SECOND ORDER DIFFERENTIAL MICROPHONE ASSEMBLY

摘要

A second-order differential (SOD) microphone includes a first-orderdifferential (FOD) microphone element installed in a housing. A pair of front soundconduits extend from respective ports to a chamber on the front side of themicrophone diaphragm, and a pair of rear sound conduits extend from respectiveports to a chamber on the rear side of the microphone diaphragm. The two frontports and the two rear ports are all substantially collinear along a minor axis, withthe rear ports intermediate the front ports or the front ports intermediate the rearports. The respective acoustic transfer functions from each port to the microphonediaphragm are equivalent. The microphone response is approximately proportionalto the second spatial derivative, along the minor axis, of a sampled acoustic pressurefield.