An air-borne converting device and a solid-borne converting device is provided in a case. The air-borne converting device has a loudspeaker for converting an electric signal into an air-borne sound, and a microphone for converting air-borne sound into an electric signal. The solid-borne device has a...http://www.google.fr/patents/US5511132?utm_source=gb-gplus-shareBrevet US5511132 - Communication device having air-borne and solid-borne transmitting and receiving devices
Communication device having air-borne and solid-borne transmitting and ...
