EIAJ MTS is a multichannel television sound standard created by the

EIAJ Founded in 1948, the Electronic Industries Association of Japan (EIAJ) was one of two Japanese electronics trade organizations that were merged into the Japan Electronics and Information Technology Industries Association (JEITA). Prior to the me ...

Bilingual Multilingualism is the use of more than one language, either by an individual speaker or by a group of speakers. It is believed that multilingual speakers outnumber monolingual speakers in the world's population. More than half of all E ...

and

stereo sound Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration ...

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 Multiplex may refer to: * Multiplex (automobile), a former American car make * Multiplex (comics), a DC comic book supervillain * Multiplex (company), a global contracting and development company * Multiplex (assay), a biological assay which measu ...

sub-carrier designation, until digital switchover to

ISDB-T Integrated Services Digital Broadcasting (ISDB; Japanese: , ''Tōgō dejitaru hōsō sābisu'') is a Japanese broadcasting standard for digital television (DTV) and digital radio. ISDB supersedes both the NTSC-J analog television system and th ...

in 2010–2012 which eventually rendered EIAJ MTS obsolete. The original System M TV standard has a

monaural Monaural or monophonic sound reproduction (often shortened to mono) is sound intended to be heard as if it were emanating from one position. This contrasts with stereophonic sound or ''stereo'', which uses two separate audio channels to reproduc ...

FM transmission at 4.5 MHz. For Japanese multichannel television sound a second channel, or sub-channel, is added to the original signal by using an FM sub-carrier at twice the line frequency (Fh, or 15374 Hz). In order to identify the different modes (''mono'', ''stereo'', or ''dual sound'') a

pilot tone An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they ar ...

is also added on an AM carrier at 3.5 times the line frequency. The pilot tone frequencies are 982.5 Hz for stereo and 922.5 Hz for dual sound. Contrary to

Zweikanalton Zweikanalton ("two-channel sound") or A2 Stereo, is an analog television sound transmission system used in Germany, Austria, Australia, Switzerland, Netherlands and some other countries that use or used PAL-B or PAL-G. TV3 Malaysia formerly used ...

these pilot tones are not coupled to the line frequency but were instead chosen to allow use of filters already employed in the Pocket Bell

pager A pager (also known as a beeper or bleeper) is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknow ...

system.

References

Broadcast engineering Television technology Sound {{tv-tech-stub

See also

References