The Model 377A21 prepolarized, 1/2 in. random incidence response microphone from PCB Piezotronics Inc., Depew, NY, operates from ICP sensor power and can be used for automobile and aerospace cabin testing, church and concert hall testing, environmental tests with sound level meters, and reverb chamber testing. Linear frequency range is 4 Hz to 20,000 kHz (±2 dB), distortion factor is 3%, max. amplitude at which the microphone can measure and still be linear is 155 dB, and noise floor rating is 20 dB(A). The sensor is specifically designed for applications in which you are looking to measure diffuse sounds or the total sound coming from different locations.
PCB Piezotronics Inc.