Ray Dolby, Who Put Moviegoers in the Middle of It, Is Dead at 80

He developed Alzheimer’s disease several years ago and received a diagnosis of acute leukemia in July, his company, Dolby Laboratories, said in announcing the death.

The Dolby name became synonymous with high fidelity. For his pioneering contributions to audio engineering, Dr. Dolby received an Oscar, several Emmy Awards and a Grammy.

Trained in engineering and physics, he started Dolby Laboratories in London in 1965 and soon afterward introduced technology that produced cleaner, crisper sound by electronically reducing the hiss generated by analog tape recording.

Decca Records was the first customer to buy the Dolby system. The noise-reduction technology quickly became a staple of major labels.

Film studios began adopting the system in the 1970s, beginning with Stanley Kubrick’s 1971 film “A Clockwork Orange.” Dolby Laboratories introduced digital surround-sound technology to home entertainment in the 1980s.

Film industry executives credit Dr. Dolby with enabling directors like Steven Spielberg to endow sound with the same emotional intensity as pictures. The producer Sidney Ganis, a former president of Paramount Pictures, recalled the powerful scene in the 1977 Spielberg film “Close Encounters of the Third Kind,” in which the mother spaceship of an alien race hovers above Devils Tower in Wyoming and communicates with scientists on the ground through a series of electronically produced tones.

“The sound of the spaceship knocked the audience on its rear with the emotional content,” Mr. Ganis, a former president of the American Academy of Motion Picture Arts and Sciences, said in an interview. “That was created by the director, but provided by the technology that Ray Dolby invented.”

Ray Milton Dolby was born on Jan. 18, 1933, in Portland, Ore., to Earl Milton Dolby and the former Esther Strand. His father was a salesman. An inveterate tinkerer with mechanical devices, Dr. Dolby was interested in how sound worked from a young age and took clarinet lessons.

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.