Walkman is a Sony brand tradename originally used for portable audio cassette players, and now used to market Sony's portable audio and video players as well as a line of former Sony Ericsson mobile phones. The original Walkman introduced a change in music listening habits by allowing people to carry music with them and listen to music through lightweight headphones.
The prototype was built in 1978 by audio-division engineer Nobutoshi Kihara for Sony.The original Walkman was marketed in 1979 as the Walkman in Japan and, from 1980, the Soundabout in many other countries including the US