(under subclass 384.1) Subject matter wherein the audible signalling means is provided with a vibrator device for converting energized electrical signals into audible sounds in such a manner that the operation of the device depends on the interaction between electric charge of the energized electrical signals and the deformation or mechanical stress property of a crystal or ceramic element incorporated into the device.
SEE OR SEARCH CLASS
84, Music,
730, for electrical musical tone generator instrument with piezoelectric transducer.
367, Communications, Electrical: Acoustic Wave Systems and Devices,
180, for piezoelectric receivers and subclass 155 for underwater type piezoelectric transducer array.
381, Electrical Audio Signal Processing Systems and Devices, 190, for electrostrictive, magnetostrictive, or piezoelectric electro-acoustic audio transducer.
