Turtles use low-pitched underwater vocalizations to communicate with each other. Scientists theorize that baby sea turtles in their eggs rely on vibrations to communicate and synchronize their hatching, improving their chances of survival.
While turtles are able to communicate with each other, they do so rarely and at a frequency difficult for humans to hear, accounting for the long-held belief that turtles are deaf and dumb. To enable better travel through the water, the vocalizations are extremely low-pitched. Turtles do not communicate above water in this manner.
Unfortunately, once captured or domesticated, turtles stop vocalizing. Scientists have witnessed captured turtles continue to vocalize for a few days after being placed in a wading pool, but they unfailingly fall silent afterwards.
The scientist chiefly responsible for discovering how turtles communicate, Richard Vogt, suspected that turtles could vocalize after observing males courting females, noting that their beaks opened and closed without them trying to bite. Another researcher, Gerard Kuchling, points out that the new information greatly impacts scientists' understanding of the effects of noise pollution on turtles, whose lives may be disrupted.
As of 2014, only 40 species of turtles have been recorded making noise. However, Vogt believes that every turtle species communicates through vocalization.