Commonly called mono sound, mono, or non-stereo sound, this early sound system
used a single channel of audio for sound output. In monophonic sound systems, the
signal sent to the sound system encodes one single stream of sound and it
usually uses just one speaker. Monophonic sound is the most basic format of
sound output.
New Adventures in Hi-Fi This "Hi-Fi & Computer" audio article cuts through the techbabble and tells the story of multi-channel audio, and details the latest 'high resolution' surround sound formats.
Surround Sound Past, Present, and Future (PDF) A history of multichannel audio from mag stripe to Dolby Digital. The first commercially successful multichannel sound formats were developed in the early 1950s for the cinema. At the time, stereophonic sound, a concept new to the public, was heavily promoted along with new wide-screen formats by a film industry feeling threatened by the rapid growth of television.