The professor's voice is preserved on the soundtrack. When Professor Higgins stomps down the stairs, he knocks a record player that starts playing a recording of Ladefoged making vowel sounds.
Peter Nielsen Ladefoged was born Sept. 17, 1925, in Sutton, England, to Niels, an importer of Danish bacon and cheese, and his wife, Marie Frances.
After serving in the British army near the end of World War II, Ladefoged enrolled in the University of Edinburgh in Scotland.
He intended to study English literature but soon became fascinated by the sounds of speech.
"I wanted to find out why Shelley could write better-sounding poetry than I," he told The Times in 1970.
Ladefoged never answered that question but earned a master's degree and then a doctorate in phonetics in 1959 at Edinburgh.
He returned to Nigeria, where he had already spent a year, to record speakers of about 60 languages.
Within a few years, he had traveled to Africa, Mexico, India and Uganda. Later, he went to Australia, Papua New Guinea, China, Brazil and many other countries.
When he married in 1953, his wife, Jenny, became his collaborator. He promised they would visit every continent, and they did.
The 6-foot-tall, genial professor was known for his sense of humor. In his e-mail address, Ladefoged called himself "oldfogey."
One of the 10 books he published, "A Course in Phonetics," was just released in its fifth edition and is widely used in college classrooms. "The Sounds of the World's Languages" (1996), written with his research partner Ian Maddieson, described every sound the two had come across and became a prominent reference work.
Ladefoged said linguists should record languages but not necessarily try to save them, even though he predicted that all but a handful of the world's 6,500 languages would disappear over the next thousand years.
Preserving languages, he argued, could weaken national unity, encourage tribalism and absorb scarce resources that might otherwise be used for development.
Deciding what language people should speak is "not our decision to make," Ladefoged told National Public Radio in 1999. "It's up to the people themselves."
In addition to his wife, Ladefoged is survived by two daughters, Lise Friedman and Katie Weiss; a son, Thegn; and five grandchildren.
Instead of flowers, the family requests contributions be sent to the Endangered Language Fund, 300 George St., Suite 900, New Haven, Conn., 06511.
