Sony Corp. has vowed to fight iPod's domination in portable digital music players by featuring superior sound quality and simple music downloads that won't require a computer.

The latest upgrades of Walkman digital music players and an Internet-linking audio console called NetJuke are aimed at raising market share first in Japan, Hiroshi Yoshioka, a Sony executive overseeing the audio equipment business, said last week.

The marketing blitz set to start Saturday will highlight the electronics and entertainment company's sound technology and expertise in household appliances that it hopes may counter Apple Computer Inc.'s weaknesses in those areas, he said.