Turtle Talk: Exactly how do turtles communicate?

Turtles comprise one of the oldest living groups of reptiles, with hundreds of species found throughout the world. Many have been well-researched, and scientists know very specific things about their various evolutionary histories, metabolic rates, and the ways in which their sexes are determined. But there was one very obvious thing that has been largely left unknown by science until very recently. Turtles can make sounds.