When the Walkman was invented in 1979, listening to music with earphones on-the-go wasn't common practice. It was shown off in the first demonstration by a skateboarder.
Sony has fallen behind competitors from Asian countries to which Japan was once an economic and manufacturing success to emulate. Samsung Electronics Co. of South Korea has emerged dominant in household electronics including TVs and newer product categories such as tablets and smartphones.
In ultra-HD TVs called "4K," the Chinese makers are quickly catching up.
Even the future of the PlayStation 4 is not assured because game players are switching increasingly to mobile devices. The switch to mobile games is especially pronounced in Japan, where Sony has never had to take the threat from Xbox One seriously.
If PS4 sales trail off, that would be a problem. Much of the console's profits come from game software.
Yasunori Tateishi, who has written books on Sony's fall from grace, fears that eventually Sony will be reduced to its entertainment business such as music, movies and perhaps games.
The biggest problem is that Sony President Kazuo Hirai has been selling pieces of the company, instead of investing in the future as did his predecessors, including founder Akio Morita, he said.
Hirai has repeatedly said Sony's smartphones, tablets and imaging technology are still scoring success, and its engineers are working hard to come up with dazzling products. He is promising a turnaround through his reforms.
That hasn't stopped him from being peppered with questions from investors who have heard engineers are quitting in droves, endangering Sony's ability to come up with innovation. Hirai has not directly addressed such questions.
"Mr. Hirai has not scripted out a scenario for the future," Tateishi said, stressing that PlayStation 4 will not be enough to save Sony's electronics. "It's just a game machine."
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