stereo

Walkman is a Sony brand tradename originally used for portable audio cassette/tape players in the late 1970s.
The original Walkman actually introduced a change in music listening habits by allowing people to carry recorded music with them and listen to music through lightweight headphones.
The prototype was built in 1978 by audio-division engineer Nobutoshi Kihara for Sony co-founder Masaru Ibuka. Ibuka wanted to be able to listen to operas during his frequent trans-Pacific plane trips, and presented the idea to Kihara.
The original idea for a portable stereo is credited to Brazilian-German inventor Andreas Pavel.
The first Walkman was marketed in 1979 in Japan, using the name Walkman.