Abstract: A solid state transducer is disclosed. The transducer comprises a micromachined electrostatic actuator formed of silicon, a support brace disposed about the actuator, and a membrane coupled to the support brace. The actuator is operatively coupled to the membrane. The transducer may be either a receiver or a microphone.

Abstract: An acoustic transducer is disclosed including: a fixed perforated member; a freely movable diaphragm spaced from the perforated member; a support ring in the perforated member maintaining the proper spacing between the diaphragm and the perforated member near the perimeter; means of suspension allowing the diaphragm to rest freely on the support ring and yet mechanically decouples the diaphragm from the perforated member; means of applying an electrical field in the space between the perforated member and the diaphragm; means of detecting the change of electrical capacitance between the perforated member and the diaphragm when the diaphragm moves in response to an incident acoustic sound pressure wave.

Abstract: An acoustical transducer including a case and a support member, diaphragm, and backplate located within the case. The diaphragm is connected to the support member and is capable of vibrating. The backplate is mounted to the support member and is spaced a distance from the diaphragm to provide a gap between the backplate and the diaphragm. An electret material on the backplate cooperates with the diaphragm to develop a signal which is transmitted to an amplifier. By having an assembly wherein the backplate does not contact the diaphragm, the capacitance of the assembly is reduced.

Abstract: An interface device is provided for (1) automatically diagnosing the type and terminal connections of the earphone and microphone transducers used in any handset or headset and (2) automatically connecting any transducer set provided as a replacement handset or headset to emulate the original handset or headset. Subsequently, the user can connect, without further action, the replacement transducer set to the telephone base station.