Whale song
Whale song was a form of communication made by the male humpback whale of Earth. The male humpback would sing his song anywhere from six to as long as thirty minutes and then start again. In the ocean, other whales picked up his song and passed it on. The songs changed every year, and until the 23rd century, served an unknown purpose. Long speculated as some sort of navigational signal or as part of a mating ritual, the truth behind the whale song was not determined until long after their extinction. 

In 2286, an unknown alien probe entered the Sol system emitting a high frequency transmission, focused on Earth's oceans. It was later determined that the probe's transmissions were, in fact, whale song. This transmission disrupted other communications and endangered starships in the vicinity of Earth. James T. Kirk decided to take the  back in time to retrieve some humpbacks so the whales could make contact with the probe and save Earth from the probe's attempts at communication. ()

The beluga whale crew members aboard the  communicated by chattering sounds, which were either understood by their humanoid crewmates or conveyed using the universal translator. ()

External link

de:Walgesang
Earth languages