According to Kid's Questions site, Turtles (and tortises) don't have any "outer ear," the part that sticks out from your head, but they have all the same "inner ear" mechanisms that other animals do. The outer ear gathers sound vibrations to make them louder. So turtles do not hear sounds as loudly as you do, but they can sense and interpret vibrations in the environment. Hearing isn't very important to turtle though, because their senses of vision and smell are excellent.