Tom Keith, 64, the virtuoso sound-effects man who for more than 30 years was a one-man band, zoo and noisemaker on Garrison Keillor’s popular radio program, “A Prairie Home Companion,” died Oct. 30 on the way to a hospital in his home town of St. Paul, Minn.

The cause of death was cardiac arrest, said his twin sister, Terry Green.

Keith was a constant creative presence on the Saturday variety show, which first aired in 1974 and is distributed by American Public Media on 600 radio stations.

For the 4 million weekly listeners who tune in to hear about the news from Lake Wobegon, the travels of the philosophizing cowboys Dusty and Lefty and the misadventures of the hapless detective Guy Noir, Keith was not a technician but a comedian in his own right.

A former sound engineer, he received little training in acting but had an innate talent for mimicry. He was able to produce almost any sound requested by Keillor, who writes the scripts almost entirely on his own, usually the day before the live recording, cast member Sue Scott said.

For the past decade, Keith participated mainly in recordings made at the show’s home venue, the Fitzgerald Theater in St. Paul. Fred Newman, the sound-effects man who performs with the traveling cast, said in an interview Tuesday that Keith was an old-school radio talent who played his table of sound-effects props “like a piano.”

Keith made many of his tools himself. He discovered that bending a box of cornmeal mimicked the sound of footsteps in fresh snow. The galloping hooves of Dusty’s and Lefty’s horses were actually coconut half-shells that Keith clopped in a container of gravel. By rubbing a balloon, he recreated the sound of a ship’s ropes groaning in the wind.

He was “a connoisseur of Styrofoam,” he once said, having discovered that crushing egg cartons made the sound of breaking wood.

Keith’s repertoire also included dentist drills, explosions and almost any animal call.

There was one animal he couldn’t “do.”

“I can’t do elephants,” he told a North Carolina newspaper in 1994. “I just don’t have the right lips.”

Keith owed his career in part to the harsh Minnesota winters. In the early 1970s, he was a sound engineer on Minnesota Public Radio’s “Morning Show,” which Keillor hosted. When bad weather delayed Keillor’s arrival at the studio, Keith filled the air with music.

The two men bonded over the crack-of-dawn recording sessions, Keith’s sister recalled, and Keillor invited Keith to join the show as an on-air personality.

Keith continued to perform with “A Prairie Home Companion” until his death. Live audiences at the Fitzgerald Theater knew him by his trademark attire: sweater vest, bow tie.

Thomas Alan Keith was born Dec. 21, 1946, in St. Paul, one of four children. Their father, a manager at the 3M company, had a “Johnny Carson-quick sense of humor,” Keith’s sister said, and regularly performed on local radio.

Survivors include his wife of 11 years, Ri Wei Liu-Keith of Woodbury, Minn.; his sister; and two brothers.