A Companding System for Multichannel TV Sound

The US Federal Communications Commission recently authorized the broadcast of multichannel sound for television. A five-year industrywide effort sponsored by the Electronics Industries Association resulted in a new standard for transmission of stereo information with the simultaneous opportunity for broadcasting a separate Second Audio Program (SAP) channel. This standard includes a unique three-part companded noise-reduction system intended to allow broadcasters to increase their programing options without reducing present coverage area.