Abstract: A piezoelectric speaker is provided which provides a magnetic field to couple the speaker to a hearing aid coil. The magnetic field induces a current in the hearing aid coil as it appears as a time varying magnet field to the coil. The time varying magnetic field is preferably proportional to the movement of a piezoelectric member of the piezoelectric speaker so as to induce a current in the hearing aid coil proportional to this movement. Such a magnetic field may be provided by connecting a magnetic material to the piezoelectric speaker such that motion in the speaker results in motion of the magnetic material, preferably at the position of maximum displacement of the speaker. Thus, the piezoelectric speaker may provide hearing aid compatibility.

Abstract: The present invention includes a system for testing the acoustical performance of a cellular communication system and includes a field unit such as a cellular phone that can both send and receive signals to and from a base station. The base station is connected to a testing computer via digital communication lines for transmitting the test data. The system prevents the signal between the base station and the testing computer from being transferred through an analog central office that may cause unknown noise to be inadvertently included within the signal and prevent accurate testing and calibration of the communication system. Audio messages may be sent from the field unit to the testing computer for testing, or the audio messages may originate at the testing computer and then sent to the field unit. The system further provides for results from the testing to be sent to a technician at the field unit to allow for evaluating and making any changes within the communication system.

Abstract: An accessory unit for operation of a cellular telephone, including a casing, a microphone mounted to the casing, a first sound emitting element mounted to the casing for providing an audible alert signal, and a second sound emitting element mounted to the casing for providing voice communication. A vibrating element is mounted to the casing for providing a mechanical alert signal, and a connector port is connectable to the telephone for communicating received sound to the telephone and receiving voice communication from the telephone. The connector port also receives actuating signals for both the first sound emitting element and the vibrating element from the telephone. A gasket is between the microphone and both the second sound emitting element and the vibrating element, and selectively has a first stiffness when the second sound emitting element is providing voice communications, and a second stiffness greater than the first stiffness when the vibrating element is providing a mechanical alert signal.