Ray Dolby

Sound sultan played clarinet as a child. Hired by Ampex at age 16, played integral role in developing company's first videotape recording system; left to get Ph.D. in physics at England's University of Cambridge. Founded Dolby Laboratories in London 1965; made fortune by eliminating background noise from recordings. Public 2005; shares up 15% in the past 12 months. Acquired cell phone sound-compression outfit Coding Technologies last November for $250 million.