The latest models, which go on sale in the U.S. next month, will be the first of Sony's digital music players to have built-in noise-cancellation technology. The company has already implemented it in some of its headphones.
Apple's iPod commands top market share in Japan, with some research putting its share at about half or higher. Sony has only recently pushed its market share in Japan to about 20 percent, company officials said.
"In one sense, the products are competing against the iPod, but in another sense they are more about Sony's strengths," said Hiroshi Yoshioka, a Sony executive overseeing the audio equipment business.
The new Walkman also will let users upload music from a CD directly to the portable player without a computer. The music transfer will require an additional cable or cradle accessory to connect the Walkman to a CD player.
Sony plans to offer two models — a 2-gigabyte version for $200 and a 1-gigabyte version for $170.
Sony, which has been tackling a turnaround for more than a year, has recently succeeded in boosting global market share in flat-panel TVs, where it had also fallen behind rivals.