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Whale sounds are used by whales for different kinds of communication.〔Communication and behavior of whales, R Payne. 1983. Westview Press.〕 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 are land mammals, because other senses are of limited effectiveness in water. Sight is less effective for marine mammals because of the way particulates in the ocean scatter light. Smell is also limited, as molecules diffuse more slowly in water than in air, which makes smelling less effective. However, the speed of sound is roughly four times greater in water than 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, sonar and marine seismic surveys.〔 The word "song" is used to describe the pattern of regular and predictable sounds made by some species of whales, notably the humpback whale. This is included with or in comparison with music, and male humpback whales have been described as "inveterate composers" of songs that are "'strikingly similar' to human musical traditions".〔Payne Roger, quoted in: Author(s): Susan Milius. "Music without Borders", p. 253. Source: ''Science News'', Vol. 157, No. 16, (15 April 2000), pp. 252-254. Published by: Society for Science & the Public.〕 It has been suggested that humpback songs communicate male fitness to female whales.〔A.J. Wright and A Walsh (2010) Mind the gap: why neurological plasticity may explain seasonal interruption in humpback whale song. Journal of the Marine Biological Association of the United Kingdom, 90(8), 1489–1491.〕 The click sounds made by sperm whales and dolphins are not strictly song, but the clicking sequences have been suggested to be individualized rhythmic sequences that communicate the identity of a single whale to other whales in its group and allows the groups to coordinate foraging activities.〔Michel Andre and Cees Kamminga (2000) Rhythmic dimension in the echolocation click trains of sperm whales: a possible function of identification and communication Journal of Marine Biological Association of the United Kingdom, Vol. 80, pp. 163-169.〕 ==Production of sound== Humans produce sound by expelling air through the larynx. The vocal cords within the larynx open and close as necessary to separate the stream of air into discrete pockets of air. These pockets are shaped by the throat, tongue, and lips into the desired sound, allowing humans to speak. Cetacean sound production differs markedly from this mechanism. The precise mechanism differs in the two major suborders of cetaceans: the ''Odontoceti'' (toothed whales—including dolphins) and the ''Mysticeti'' (baleen whales—including the largest whales, such as the blue whale). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Whale vocalization」の詳細全文を読む スポンサード リンク
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