| 摘要 |
<p>Each of a pair of radio listening channels (4, 5) has a filter, a control channel (9) alternately and automatically switching the channels in response to the microphone output. A second pair of parallel listening channels (7, 8) operating via bone medium connect to second output stage vibration (13) in contact with the mastoid bones of the subject. They are controlled by the control channel (9) in the same manner as the first channels, so that in the rest state the first channels of the two pairs are in circuit and as soon as the subject speaks into the microphone, the control channel switches the second channels of the two pairs, assuring simultaneous listening by radio and bone mediums.</p> |
