It is likely that the megalodon produced low, rumbling sounds when swimming and hunting. These sounds would have been similar to the sounds produced by other large sharks, such as the great white shark and the basking shark. In addition to these low, rumbling sounds, the megalodon may have also produced higher-pitched clicks and whistles. These sounds would have been used for communication and echolocation.
The exact sounds produced by the megalodon will never be known for sure, but it is possible to get a general idea of what they might have sounded like based on the sounds produced by other large sharks and the size of the megalodon itself.