Stereophonic and two channel sound in terrestrial television broadcasting

The possibility of adding stereophonic sound to existing television services is investigated. A number of possible methods exist for the transmission and reception of the additional sound signal required for stereo and some of them are also suitable for the transmission of independent sound signals, such as may be required for a bilingual service. Several of these possibilities are described. A two carrier system was tested, but results, indicate that there may be difficulty in providing a signal that would be both compatible with existing receivers and able to provide a two channel service over the existing coverage area.