Whale Song

Whale song is the sound made by whales to communicate. The word "song" is used in particular to describe the pattern of regular and predictable sounds made by some species of whales (notably the humpback) in a way that is reminiscent of human singing.

The mechanisms used to produce sound vary from one family of cetaceans to another. Marine mammals, such as whales, dolphins, and porpoises, are much more dependent on sound for communication and sensation than land mammals are , as other senses are of limited effectiveness in water. Sight is limited for marine mammals because of the way water absorbs light. Smell is also limited, as molecules diffuse more slowly in water than air, which makes smelling less effective. In addition, the speed of sound in water is roughly four times that in the atmosphere at sea level. Because sea-mammals are so dependent on hearing to communicate and feed, environmentalists and cetologists are concerned that they are being harmed by the increased ambient noise in the world's oceans caused by ships and marine seismic surveys. (read Wikipedia full article)

Prof. Richard A. Muller course Physics for Future Presidents at Berkeley has a lecture about waves where he talks about the ocean sound channel and whales communication. Forward the video to about 35 min to watch his explanation.



Carl.Sagan's Cosmos series also talks about this issue at chapter 11, The Persistence Of Memory.