The personal stereo is the term given to a portable audio player using an audiocassette player. This allows the listening of music through headphones while a person is mobile. The first personal stereo was the Stereobelt invented and patented by Andreas Pavel in 1977. Pavel attempted to commercialise this invention but failed to do so.^[1] The first commercial personal stereo was the Sony Walkman released in 1979, created by Akio Morita, Masaru Ibuka (the co-founders of Sony) and Kozo Ohsone.