A coupler enabling communication of information between a communication device, such as a PIM device, and an acoustic device, such as a telephone, using acoustic tones. The coupler includes a speaker for transmitting information in the form of acoustic tones to the acoustic device and a speaker for receiving...http://www.google.ca/patents/US6304638?utm_source=gb-gplus-sharePatent US6304638 - Coupler for a communications device
