Researchers at the Woods Hole Oceanographic Institution in Massachusetts confirmed that longfin squid can indeed detect sound at low frequencies by the movement of their aqueous environment, ScienceDaily.com reported this week.
"They are detecting themselves moving back and forth with the sound wave," Woods Hole marine biologist T. Aran Mooney says.
He compared a squid in the ocean being jostled by a sound wave to a piece of fruit suspended in Jell-O. "If you jiggle the Jell-O, the whole block of Jell-O is moving with the fruit."
Mooney's team determined that squid can only listen in at low frequencies of up to 500 hertz. Humans, by comparison, can hear frequencies from about 20 to 20,000 hertz.
Squid can probably detect wind, waves and reef sounds, Mooney says, but not the high-frequency sounds emitted by the dolphins and toothed whales that eat them.
Mooney says researchers are working to better understand how the motion-based hearing mechanism of squid works.
"The idea is maybe if these guys do have a primitive sense of hearing, can we use them as a model to understand the foundation of hearing or how hearing is lost," he said, adding the research could ultimately be applicable to human hearing.