COMPANDED PCM VOICE OPERATION

摘要

A method and apparatus for digitizing audio signals being generated from a plurality of parties (A, B) in order to provide audio communication between the parties with a minimum of interference. Each of the parties has an audio transmitter and receiver (38, 58) provided for transmitting and receiving audio signals. The audio signals are converted (40) to a PCM companded eight-bit parallel signal followed by conversion (42) to a serial signal for transmitting to a remote location and then reconverting (46) each of the companded serial signals to a first eight-bit parallel signal. A pre-programmed ROM (48) is located at the remote location and has a plurality of inputs and outputs. Each of the eight-bit parallel signals from the individual parties are fed to the ROM causing the ROM to produce an eight-bit signal on the output representing the instantaneous sum of the eight-bit parallel signals being supplied to the inputs thereof. The eight-bit parallel signal appearing on the output of the ROM is converted to a serial-digital signal by a parallel-to-serial converter (50) for transmitting over a single line (52) to another serial-to-parallel converter (54) prior to being fed through a digital-to-analog converter to the receiver (58) for producing the audio signal at the receiver.