Friday Squid Blogging: Research into Squid Hearing
Squid can hear, scientists have confirmed. But they don’t detect the changes in pressure associated with sound waves, like we do. They have another, more primitive, technique for listening: They sense the motion generated by sound waves.
Squid have two sac-like organs called statocysts near the base of their brains. Hair cells line the sac and project into it, while a tiny grain of calcium carbonate, called a statolith, resides inside the sac. When the squid moves, the hair cells rub against the statolith, bending the hair cells inside the sac. This generates electrical signals that get sent to the animal’s brain telling the squid it has detected a sound.
Their results showed that squid can only listen in at low frequencies of up to 500 hertz. (By comparison, humans hear frequencies from about 20 to 20,000 hertz.) This means squid can probably detect wind, waves and reef sounds, but not the high-frequency sounds emitted by the dolphins and toothed whales that eat them, Mooney said.