GB1067748A - Hearing aid - Google Patents

Abstract

1,067,748. Hearing aids. H. K. PUHARICH and J. L. LAWRENCE. Nov. 25, 1963, No. 46550/63. Heading A5R. [Also in Divisions H1, H3 and H4] A hearing aid comprises a radio transmitter and receiver, the receiver being housed within a double dental cap 21 on viable teeth 10, 11 from which the crowns have been removed and being connected to exposed nerve endings 12, 13. The receiver comprises an R.F. resonant element 14 of polarized lead zirconate titanate is tuned to the carrier frequency of a transmitter 15 and is in electrical contact with nerve endings 12. Connected to the element 15 by a metal plate 16 is a diode 17 having its N-side connected to element 14 and its P-side connected through a metal plate 19 and barium titanate element 20 to nerve endings 13. Preferably element 20 is resonant in the audiofrequency range to provide physical vibratory stimulation of nerve endings 13. In operation, the R.F. transmitter 15, which is positioned in a shirt pocket or otherwise adjacent the body, is activated by a microphone 22. Element 20 may be omitted. Alternatively a dental cap (33) Fig. 2 (not shown) covering a viable "denuded" tooth (30) has embedded therein a wafer-like diode (34), the N-side of which is in electrical connection with an R.F. resonant piezoelectric element (35) tuned to the carrier frequency of a transmitter and the P-side of which is fixed to a second piezoelectric element (38) having plated terminals on its opposite sides. Element (35) has metal plated terminals (36, 37), terminal (36) being exposed for physical and electrical contact with the tongue (31) whereby nerves (32) of the tongue are utilized. Terminal (36) may be covered with polyester film (36a) in order to provide correct matching impedance between the tongue tissue and element (35). Element (38) is connected to viable nerves (39) of tooth (30) and is resonant in the A.F. range. The components may be of micro-miniature proportions using "thin film" techniques.