EIAJ MTS is a multichannel television sound standard created by the EIAJ. Bilingual and stereo sound television programs started being broadcast in Japan in October 1978 using a "FM-FM" system originally developed by NHK Technical Research Labs during 1962–1969. This system was modified and standardised by the EIAJ in January 1979. Television stations in Japan with capability for bilingual and stereo sound transmissions used the callsign JO**-TAM, where "TAM" denotes their audio FM multiplex sub-carrier designation, until digital switchover to ISDB-T in 2010–2012 which eventually rendered EIAJ MTS obsolete.