The man who revolutionised recorded sound and put movie audiences into the middle of the action with his surround sound technique has died.
Ray Dolby had been suffering from Alzheimer's disease and leukaemia.
He built a billion dollar business by reducing noise and creating a purer sound for the movie and music industries.
Dolby Laboratories remains a big player in the business.
Ray Dolby, who won a Grammy and also Emmy Awards, died in San Francisco aged 80.
