| 摘要 |
PURPOSE:To suppress the generation of noises due to external oscillation as much as possible by attaching an external body to an insertion body which is inserted into the external auditory miatus through an elastic member, and using materials with large mass for the insertion body and external body. CONSTITUTION:A sound signal transmitted by bone conduction oscillates the insertion body 2, whose oscillation is converted by a converting element 3 into an electric signal, which is sent to a transmitter 6 to be radiated as a radio wave from an atenna. Oscillation transmitted from the outside through a lead line 3a, on the other hand, is absorbed by the oscillation system consisting of the external body 5 and line 3a. Oscillation applied directly to the external body 5 is absorbed by the oscillation system of the insertion body 2 and member 4. In either case, the resonance frequency of each resonance system is preferably outside of the low band of the effective sensitivity frequency band to the element 3. For this purpose, the insertion body 2 and external body 5 are increased in mass and the elastic modulus of the member 4 should be large. Consequently, the external oscillation transmitted to the lead line 3a and that applied directly to the external body 5 are absorbed excellently to suppress the generation of noises due to the external oscillation. |
