Handheld radiotelephones are provided with battery packs that facilitate the transmission of a person's voice to internally mounted microphones. A radiotelephone housing end portion is provided with an aperture that is in acoustic communication with an internally mounted microphone. A passageway extends...http://www.google.ca/patents/US6470176?utm_source=gb-gplus-sharePatent US6470176 - Battery packs that facilitate acoustic communications and radiotelephones incorporating same
