An approach for omnidirectional audio in a communications device has a communications device housing having a front housing including an opening; an earpiece transducer that directs sound waves through the opening; an audio transducer positioned within the communications device housing to direct audio...http://www.google.es/patents/US5909490?utm_source=gb-gplus-sharePatente US5909490 - Omnidirectional audio in a communications device
