This application discloses an invention including a ceramic gradient microne insensitive to mask cavity acoustics, essentially flat in pressure response to 10,000 Hz for use in deep submergence helium atmospheres, and capable of withstanding compression, decompression and intermittent flooding. In essence, there is provided a microphone having a diaphragm mounted to a bimorph ring and includes a unique construction to provide improved frequency response and gradient characteristics, plus drainag…


