This profound puzzle challenged a global research team to record an alligator bellowing with normal air, and then breathing heliox, a helium-oxygen mixture.
The breakthrough garnered an Ig Nobel Prize for Acoustics on Thursday. The Ig Noble Prizes are an annual honor for accomplishments in science and humanities that are intended to make you laugh – then think.
“Our question was whether alligators have vocal tract resonances like human speech,” said biologist Tecumseh Fitch, a member of the research team, who came from Austria, Sweden, Japan, the United States and Switzerland. “The hard part is getting an alligator to breathe helium.”
That was solved by getting a female Chinese alligator into an airtight chamber and pumping in helium, which makes sound travel faster.
Alligators bellow a lot during mating season, possibly as a way to signal body size and mojo, the researchers said. By raising the vocal frequency, helium made the reptile sound less of a hunk.
“Crocodilian vocalizations could thus provide an acoustic indication of body size,” said the winning research paper, originally published in the Journal of Experimental Biology.