The origins of stereophonic sound and stereo sound
The technical foundations for the recording and playback of two separate audio channels were laid in the 1930s. At that time, the inventor Alan Blumlein had developed an embossing process for vinyl grooves, which is still used today. The first market-ready stereo records were pressed in the 1950s. This was the start for the two-channel sound becoming more and more widespread from the 1960s onwards.
With all the innovations in audio technology of the past decades, stereo has remained a constant as a reproduction method. Despite digitalisation, dual-channel sound is still widespread, for example in radio and television. Even sound bars do not usually deviate from the stereo principle: In the sound bars, a sound stage is basically created via two channels. The sound transducers inside are arranged accordingly and tuned to each other.