Secondary audio program

Second audio program (SAP), also known as secondary audio programming, is an audio channel for analog television that can be broadcast or transmitted both over-the-air and by cable television. SAP is part of the multichannel television sound (MTS) standard originally set by the National Television Systems Committee (NTSC) in 1984 in the United States. The NTSC video format and MTS are also used in Canada and Mexico.

SAP is often used to provide audio tracks in languages other than the native language included in the program (as a result, the facetious term "Spanish audio program" is used as an expansion to the acronym), or for the Descriptive Video Service (DVS) offered in the United States on some television stations or cable networks (primarily ABC, CBS, NBC, and PBS), along with broadcasting the local NOAA Weather Radio services or a local National Public Radio station (on many PBS stations) at times where translation or DVS is not needed. As of 2016, FCC guidelines now require stations in larger markets to read out the text of any on-screen news tickers which appear on-screen (mainly severe weather warnings) either using human intervention or via reading it out using an automated text-to-speech voice; the latter is done usually with the SAP channel exclusively.

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