As a teenager, he met Alexander Poniatoff, a Russian émigré and electrical engineer who in 1944 started Ampex, a pioneering maker of audio and later video recorders, in San Carlos, Calif. Mr. Poniatoff had gone to Ray Dolby’s high school looking for a projectionist for a talk he was going to give and young Ray volunteered. Impressed with his abilities, Mr. Poniatoff invited him to work for Ampex.

“I was so far ahead in my credits that I didn’t have to worry about getting into college, so I went to school three hours a day and worked five at Ampex,” Dr. Dolby told The Los Angeles Times in 1988.

Hired in 1949, Dr. Dolby developed the electronic components of the company’s videotape recording system.

He left the company in 1957, the same year he graduated from Stanford University with a bachelor’s degree in electrical engineering, deciding to pursue graduate studies at Cambridge University in Britain on a Marshall Scholarship and a fellowship from the National Science Foundation. He received a postdoctoral degree in physics from Cambridge in 1961. While at Cambridge, he met a German summer student named Dagmar Bäumert; they were married in 1966. She survives him, along with two sons, Tom and David, and four grandchildren.

In mid-1962, Dr. Dolby saw an announcement from the United Nations Educational, Scientific and Cultural Organization in a Sunday newspaper; Unesco was seeking an expert to help the government of India set up a new national laboratory to develop scientific and industrial instruments. Dr. Dolby applied and won the assignment.

He set off for India in 1963 and traveled the country assessing its scientific instruments industry and how the new research lab might help advance it. His stint in India turned out to be pivotal to his thinking about the problems of sound.

In his free time, Dr. Dolby hired professional musicians to play at his home so that he could make live recordings using his Ampex tape recorder. He had long been bothered by the tape hiss that distorted the sound quality of the recordings; the slower the tape speed, the noisier it became.