Utilize the input text as a context reference, choose the right relationship between Walkman and Sony from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

But now Sony was unveiling two different digital Walkman products, each of which used different proprietary technology.

Answer: manufacturer