Ray Dolby, creator of the noise-reduction system that revolutionized audio and film sound, has died. He was 80.

The engineer, who suffered from Alzheimer's and leukemia, passed away at his home in San Francisco, the firm he founded, Dolby Laboratories Inc., said in a statement.

Throughout his career, Ray Dolby obtained more than 50 patents and invented a technology for reducing noise that improved the quality of recordings in all formats, from cassette tapes to Hollywood movies.

Among his best-known products are the Dolby Stereo and Dolby Surround, installed in movie theaters and later in homes using synchronized loudspeakers that immerse the listener in the sound being played.

Dolby won an Oscar, a Grammy and several Emmys, and was awarded the National Medal of Technology by President Bill Clinton.

"Though he was an engineer at heart, my father's achievements in technology grew out of a love of music and the arts," Dolby's son, novelist Tom Dolby, said.

Ray Dolby was born in Portland, Oregon, and while still a teen worked part-time and summers for the Ampex Corporation on its first audio tape recorder.

He earned degrees from Stanford and Cambridge, and for two years was advisor in India for the United Nations, until he founded his company in 1965, which since 1976 has been based in San Francisco.

He is survived by his wife Dagmar, his sons Tom and David, and four grandchildren. EFE