| 摘要 |
<p>A mobile telephone headset 1 comprises a microphone unit 5 adapted to be positioned in the vicinity of the user's mouth to receive speech to be transmitted by the telephone, and an earpiece 6 adapted to be positioned in the vicinity of the user's ear to transmit into the user's ear speech received by the telephone from a remote caller. The earpiece 6 does not incorporate an electromagnetic coil producing an electromagnetic field extending into the side of the user's head (as in conventional telephone headsets), but instead is connected by an audio pipe 7 to a sounder integral with the microphone unit 5. Alternatively the earpiece may incorporate a crystal loudspeaker and an optical receiver module. Such arrangements ensure that the user is not subjected to an unacceptable level of radiation directed into the side of the user's head in use of the telephone.</p> |
