ELECTRODYNAMIC SOUND GENERATOR FOR HEARING AID

摘要

2062796 9101075 PCTABS00003 A miniaturized electrodynamic sound generator comprises a diaphragm, a permanent magnet with pole pieces, a magnet yoke and a coil. The yoke is designed such it constitutes a housing or a cabinet of the sound generator. The permanent magnet and the pole pieces are provided in a recess in the cabinet or the yoke and surrounded by the coil which is connected to the diaphragm at a peripheral area thereof. The diaphragm is provided above the magnet system of the recess and fastened to the outside of the cabinet. The dynamic response of the sound generator is determined by the magnetic, electrical, mechanical and acoustic parameters which are used in the design of the sound generator. By varying some of these parameters, the frequency and amplitude of a resonance may be chosen such that the sound generator may reconstruct the natural acoustic transfer function in the range 2-4 kHz in the human meatus. This makes the sound generator particularly suitable for use in hearing aids.