Patent ID: 8175237

Claim:
An audio interface comprising: interface circuitry configured to translate audio signals received from a military handset to audio signals compatible with a plain old telephone service (POTS) network, the interface circuitry having an input and an output; a multi-pin audio port coupled to the input and configured to couple the military handset to the interface circuitry; and a 2-wire POTS connector coupled to the output and configured to couple the interface circuitry to the POTS network, wherein the interface circuitry comprises tone circuitry configured to add a POTS network dial tone to the audio signals, first buffer circuitry configured to provide impedance matching between the military handset and the tone circuitry, a phone line interface (PLI) circuitry configured to convert a format of the audio signals between a military handset format and a POTS network format, wherein the converting comprises conditioning and isolating the audio signals, volume circuitry configured to provide volume control for the audio signals, and second buffer circuitry configured to provide impedance matching between the volume circuitry and the military handset.