Gradient Microphone

A microphone where the directivity is determined by the difference (gradient) between frontal and rear input to the membrane. All 1st order directional microphones have some gradient component. A pressure microphone (zero order) does not have a gradient component. See 1st Order Pattern. Figure 1 Left microphone is a gradient type (inlet to both the front and rear of the diaphragm), and the right microphone is a pressure type (only admittance from one side of the diaphragm).