The original Walkman was marketed in the 80s as the Walkman in Japan, the Sound about in many other countries including the US, Freestyle in Sweden and the Stowaway in the UK. The device was created by audio division engineer Nobustoshi kihara for Sony co-chairman Morita, who wanted to be able to listen to operas during his frequent transpacific plane trips. Morita hated the name "Walkman" and asked it to be changed, but relented after being told by junior executives that a promotion campaign had already begun using the 'Walkman' name and would be too expensive to change.
However, the first portable personal stereo audio cassette player, called Stereo belt, had been invented earlier by the German-Brazilian Andreas Pavel in 1972, and patented in the U.S. in 1978. After lengthy legal battles, Andreas Pavel was finally recognized by Sony in 2003 as the original inventor of the Walkman.
The names "Walkman", "Pressman", "Watchman", "Scoopman", "Discman", and "Talkman" are trademarks of Sony, and have been applied to a wide range of portable entertainment devices manufactured by the company. Sony continues to use the "Walkman" brand name for most of their portable audio devices, after the "Discman" name for CD players was dropped in the late 1990s. According to Sony, the plural form is "Walkman Personal Stereos", rather than "Walkmans" or "Walkmen" (presumably to preserve their trademark on "Walkman").
In March 2007, Sony extended the Video Walkman brand by launching its first digital, flash-based video Walkman, the NW-A800/810 series, where A stands for "All in one", "Advanced", and "Attractive".