Increasing Voice Communication Channels Using Man's Binaural Listening Capability 1

Sending voice messages over pairs of channels makes available more channels for communication than would be possible if channels were used in a conventional manner and only one message was sent over one channel. Although this means that all channels under the dual channel system must carry several messages simultaneously, it is shown that for subjects wearing earphones, message intelligibility remains remarkably higher than if the same number of messages are sent over a single channel. The superiority of the dual channel method is attributed primarily to the unique capability of the human ear-brain system to perceive diotic signals as being located in the center of the head while all dichotic signals are perceived as being off to the side of the head. Where seven voices are talking simultaneously intelligibility of messages under the dual channel method of transmission is about 94 percent as compared to 11 percent under the single channel method.

Practical implications of these findings for a number of military and civilian communication situations are discussed.