simulcast

Simulcast, a portmanteau of simultaneous broadcast, is the broadcasting of programs or events across more than one medium, or more than one service on the same medium, at exactly the same time. For example, Absolute Radio is simulcast on both AM and on satellite radio, and the BBC's Prom concerts were formerly simulcast on both BBC Radio 3 and BBC Television. Another application is the transmission of the original-language soundtrack of movies or TV series over local or Internet radio, with the television broadcast having been dubbed into a local language.