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.

Around the same time that teams at Sony starting exploring ideas about a digital Walkman in 1999, Steve Jobs, the CEO of Apple, sat down with a team of engineers to try to create his own digital music experiment.
manufacturer