An audio communications control system operates between multiple voice communications systems and a single headset worn by an operator accessing the multiple communications systems via voice transmission. The single headset includes a left speaker, a right speaker, and a microphone. The audio interface provides an electrical connection and operation with each of the voice communications systems, even though each may operate with differing equipment and signal processing. The audio interface switches discrete voice communications signals and routes them to one of the left speaker, the right speaker, and conversely from the microphone of the headset to any of selected systems.