Patent ID: 7499555

Claim:
A personal communication device comprising: a receiver module for receiving signals arriving at the personal communication device, the receiver module having: two displacement sources that are not in phase and formed by at least one driver, each displacement source having an acoustic center, two separate acoustic cavities, each acoustic cavity corresponding to one of the displacement sources, and two acoustic output ports each having an acoustic center, each acoustic output port corresponding to one of the displacement sources and in acoustic connection therewith via the corresponding acoustic cavity such that the length of acoustic path between the acoustic centers of the two acoustic output ports is less than the distance between the acoustic center of each output port and the acoustic center of the corresponding displacement source to which the output port is acoustically connected; and a transmit module for transmitting signals from the personal communication device, wherein the output ports of the receiver module are driven and tuned such that when the communication device is worn by a person, the ratio of acoustic pressure at a first location to acoustic pressure at a second location further away from the output ports than the first location is substantially greater than that with either port acting alone over a predetermined frequency range.