In a world where a one-minute trailer could spell the difference between finding your audience or falling into oblivion, one man's voice had the power to save a movie. In Hollywood, that man was Don LaFontaine, who has died aged 68.

While his name may not be familiar to many, or even his picture, his baritone voice, with its deep resonance and portentous timbre, is instantly identifiable from trailers for thousands of coming attractions in cinemas all over the English-speaking world. His ability to impart gravitas to run-of-the-mill films was much admired, and thus, in Hollywood, much imitated, becoming the industry standard. "It's a deep, rich, authoritative sound. Everybody copies him," said his fellow voiceover artist Melissa Disney.

LaFontaine could make the dullest melodrama seem epic and give depth to the simple action movie's bombast. "My voice lives in an area of the sound spectrum that nothing else lives in," he explained, "so I can speak very quietly and it cuts through explosions, it cuts through everything."

He became famous for speeding around Hollywood to as many as 35 jobs a day in a chauffeur-driven limousine so that he would not waste time parking. With the advent of high-quality telephone lines, however, he worked from home and became even more prolific, his income running into millions of dollars a year. He said that he considered himself not an announcer, but a "voice actor" - one that gets credit "only in their bank accounts".

Yet he never took his success seriously. He would record answering machine messages for fans and was happy to parody himself, not least in a highly successful commercial for an insurance company, where, billed as "that announcer guy from the movies", he turns the story of one claimant into the stuff of movie magic. On a television comedy show, Frank TV, he joined two colleagues in a Three Tenors parody, combining lines from different genres of blockbusters, all delivered in pure LaFontaine style, complete with faux-Pavarotti handkerchief mopping his brow.

LaFontaine was born in Duluth, Minnesota, and after high school joined the army, where he served as a recording engineer for the US army band and chorus. After his discharge, he moved to New York and got a job with National Recording Studios, where he met the producer Floyd Peterson. After collaborating on a radio promotion for Stanley Kubrick's Dr Strangelove, they went into business together making film trailers.

In 1965, when a voiceover artist failed to show up to record a promotion for a western called Gunfight at Casa Grande, LaFontaine stepped in. MGM were pleased with the result, and he began to do more voice and less production. He became head of production at Kaleidoscope Films before starting his own company, where his first job was the trailer to The Godfather, Part II (1974). He moved to Los Angeles and, apart from a brief hiatus as head of production for Paramount Pictures' trailer department, he freelanced for the rest of his career. He attributed part of his success to his experience in production and writing: "I say the words the way they demand to be said."

In total he voiced an estimated 5,000 trailers, 350,000 commercials and countless TV continuity spots, including two years as the announcer for WCBS News in New York. His favourite was his trailer for David Lynch's The Elephant Man, his voice playing a part in turning the film into a cult classic.

He is survived by his second wife, the actress and singer Nina Whitaker, and three daughters, one from his first marriage to Joan Studva, which ended in divorce.

· Donald LaFontaine, voice actor, born August 26 1940; died September 1 2008