When and by whom was stereo sound invented?
The concept of stereo (from the Greek ‘stereos’, meaning solid) came from stereoscopic photography, which can produce an incredible 3-D illusion. Many have experienced this with the Viewmaster stereo slide system, popular in the 1950s and 60s. The earliest use of stereo sound was through experimentation with binaural sound in the late 19th century. Binaural audio used two microphones to capture sound and headphones for listening. This method remains in use to this day with, for example, the Bruel and Kjaer Type 4101 binaural microphone, which is worn by a person in much the same way as portable headphones. An early two-channel playback system, developed and sold in the early 20th century, used a two-channel phonograph cylinder and two mechanical pickups and horns. Our modern concept of stereo sound comes from two sources: Alan Blumlein of EMI in England and Arthur Keller of Bell Laboratories in the US. These two groups followed quite different paths. Bell Labs in the US began experimen
