Scientists may have captured the song of a new species of whale living in the Antarctic. The song can’t be identified and doesn’t fit the pattern of noise generated by the few known species of beaked whale, raising hopes that it could be coming from a completely new species. While beaked whales make up the second largest family of cetaceans, relatively little is known about them, mainly because they spend very little time on the water’s surface. Experts are sure the noise isn’t made by Arnoux's beaked whales or Cuvier's beaked whales (stock image), because the signal doesn’t match . There are 22 species of beaked whale and all of them are elusive deep divers, meaning that they are most often identified by their songs, which they use to navigate. The mysterious ‘Antarctic BW29 signal was recorded near the Orkney Islands, South Shetland Islands, and Antarctic Peninsula by scientists led by Jennifer Trickey of the Scripps Institution of Oceanography, at the University of California, in La Jolla, California. They have recorded the noise more than 1,000 times to conclude that it’s unique in the composition of sounds making the signal and in timing, BBC Earth reported. ‘Given that new species of beaked whale are still being discovered, the source of these Antarctic signals might be a species that has yet to be identified,’ the study says. But the song belong to a strap-toothed whale, a southern bottlenosed whale or a Gray’s beaked whale (pictured), according to the study, despite the sound being the wrong frequency for a Gray’s beaked whale . Whale sounds are used by whales for different kinds of communication. The word 'song' is used to describe the pattern of regular and predictable sounds made by some species of whales. Only males 'sing'. While the complex sounds of the humpback whale and some blue whales are believed to be primarily used in sexual selection, all whales use simpler sounds all year round to communicate. Whales occupying the same geographical areas, which can be vast, tend to sing similar songs with only small variations. Male humpback whales have been described as 'inveterate composers' of songs and experts have said that their songs are similar to human music in many ways. Experts are sure the noise isn’t made by Arnoux's beaked whales or Cuvier's beaked whales, because the signal doesn’t match their songs. But it could belong to a strap-toothed whale, a southern bottlenosed whale or a Gray’s beaked whale, according to the study, published in the Journal of Marine Mammal Science. It is very rare for strap-toothed wakes to be sighted as far south as the noises have been heard, while the noise is the wrong frequency for a Gray’s beaked whale, leaving the southern bottlenosed whale as the most likely match. But again there’s a problem, because the whale’s relative, the northern bottlenose whale, makes very different calls, leading experts to think that the southern species probably vocalises in a similar way – unlike the Antarctic BW29 signal. Experts have also recorded an ‘Antarctic BW37’ signal on six occasions, which is of a higher frequency. ‘It remains unknown whether this belongs to a different beaked whale species than the one producing Antarctic BW29,’ they write. Because frequency is usually linked to a whale’s size, there is a theory that the Antarctic BW29 song may be made by a southern bottlenose whale, while the higher pitched Antarctic BW37 song could be made by a smaller Gray’s beaked whale. There’s also a chance that new species of whale could sing at different frequencies, but this ability would be unique among beaked whale species. Last year, a study revealed that the shy Cuvier's beaked whale performs the deepest dives made by any mammal on the planet at 9,816ft (2,992metres) below the waves - the equivalent of just under seven Empire State Buildings - and stays below for 138 minutes . A study published last April has revealed that the shy Cuvier’s beaked whale performs the deepest dives made by any mammal on the planet. Scientists were surprised to record one of the mammal's dives, which was 9,816ft (2,992 metres) below the waves. And the whale stayed up to two miles below - around the depth of just under seven Empire State Buildings on top of one another - for 138 minutes. The New York landmark measures 1,250ft (381 metres) in height, excluding its tip. It is the first time that the diving behaviour of the species has been carefully examined and scientists are particularly interested in them because of the suspected effects of sonar - a system using transmitted and reflected underwater sound waves to detect and locate submerged objects. Marine mammal biologists at the Scripps Institution of Oceanography in La Jolla, California, tagged eight of the whales off San Nicholas Island in southern California and followed them for several months as they dived for food.
Antarctic song doesn't fit the pattern of noise made by beaked whales . Beaked whales are elusive deep divers about which  little is known . Song could hint at a new species or could be made by a southern bottlenosed whale, although experts have their reservations .