Baleen whales produce primarily low-frequency sounds - mostly well below 5,000 Hz.
- Such sounds may be the loudest produced by any animal and may travel for hundreds of kilometers under water.
- Researchers speculate that these loud sounds may be for long-range contact, assembly, advertisement for mates, greeting, location, orientation, threat, navigation, or individual identification. Research is ongoing.
Specific vocalizations vary by species.
The repertoire of baleen whale sounds includes very low-frequency (20–200 Hz) moans, grunts, thumps and knocks; and higher-frequency (above 1000 Hz) chirps, cries, whistles, and songs.
Humpback whales also produce a series of repeating units of sounds (up to 8,000 Hz) that are classified as "songs".
- Songs are produced by males, and only while in breeding grounds.
- More analysis is needed before the function of whale songs is understood, and any adaptive advantages of singing are as yet unknown. Experts speculate that such vocalizations may keep males spaced apart; attract females; make it possible for whales to locate each other; or communicate information such as species, sex, location, mate status, and readiness to compete with other males for mates. There have been no conclusions.
The location of sound production is unknown but the larynx is suspected. Baleen whales have no vocal cords.
Whales produce some sounds via body displays. Such sounds may be involved with communication. Noises such as forceful spouts may signal aggravation. Slapping pectoral flippers or flukes may indicate arousal, excitement, or aggression.
There is no evidence that baleen whales echolocate the way toothed whales do. Studies have shown, however, that bowhead whales produce low-frequency sounds that may give the whales information about the ocean floor and locations of ice.