Editing Whale vocalization (section)

== Types and purpose of vocalization ==
While the complex sounds of the humpback whale (and some blue whales) are believed to be primarily used in [[sexual selection]],<ref>{{Cite journal |last1=Smith |first1=Joshua N. |last2=Goldizen |first2=Anne W. |last3=Dunlop |first3=Rebecca A. |last4=Noad |first4=Michael J. |year=2008 |title=Songs of male humpback whales, Megaptera novaeangliae, are involved in intersexual interactions |journal=Animal Behaviour |volume=76 |issue=2 |pages=467–477 |doi=10.1016/j.anbehav.2008.02.013 |s2cid=29660106}}</ref> there are simpler sounds that are created by other species of whales that have an alternative use and are used all year round.{{cn|date=November 2021}} Whale watchers have watched mother whales lift their young towards the surface in a playful motion, while making a noise that resembles cooing in humans.<ref name=":12">{{Cite journal |last=Milstein |first=Tema |date=2008-07-01 |title=When Whales "Speak for Themselves": Communication as a Mediating force in Wildlife Tourism |journal=Environmental Communication |volume=2 |issue=2 |pages=173–192 |doi=10.1080/17524030802141745 |issn=1752-4032 |s2cid=145304686 |doi-access=free|bibcode=2008Ecomm...2..173M |hdl=1959.4/unsworks_77050 |hdl-access=free }}</ref> This cooing-like noise made by whales seems designed to relax their young<ref name=":12" /> and is one of several distinct everyday noises whales are known to make. Unlike some fish such as sharks, a toothed whale's sense of smell is absent, causing them to rely heavily on echolocation, both for hunting prey and for navigating the ocean under darkness.{{cn|date=November 2021}} This requires the whales to produce noise year round to ensure they are able to navigate around any obstacles they may face such as sunken ships or other animals.{{cn|date=November 2021}}

It has also been proven that whales are extremely social creatures. The noises that are made throughout the entire year (the main sounds being whistles, clicks, and pulsed calls) are used to communicate with other members of their pod.<ref name=":4">{{Cite web |last=US Department of Commerce |first=National Oceanic and Atmospheric Administration |title=Why do whales make sounds? |url=https://oceanservice.noaa.gov/facts/whalesounds.html |access-date=2021-10-24 |website=oceanservice.noaa.gov |language=EN-US}}</ref> Each sound a whale makes could mean something different. The clicking noises whales make are used for navigation.<ref name=":4" />   

The question of whether whales sometimes sing purely for [[aesthetics|aesthetic]] enjoyment, personal satisfaction, or 'for art's sake', is considered by some to be "an [[Experiment|untestable question]]".<ref>Entomologist and ecologist [[Thomas Eisner]] called it "an untestable question in scientific terms", quoted in: Milius (2000), p. 254</ref>

=== Song of the humpback whale ===
[[Image:HumBack2.jpg|right|thumb|300px|[[Spectrogram]] of humpback whale vocalizations. Detail is shown for the first 24 seconds of the 37 second recording below.]]{{Listen
| filename     = Humpbackwhale2.ogg
| title        = Humpback Whale Song
| description  = Recording of humpback whales singing.
| format       = [[Ogg]]
}}
Interest in whale song was aroused by researchers [[Katy Payne|Katy]] and [[Roger Payne]] as well as Scott McVay after the songs were brought to their attention by a Bermudian named Frank Watlington who was working for the US government at the SOFAR station listening for Russian submarines with underwater [[hydrophones]] off the coast of the island.<ref>{{cite book |author=Rothenberg, David |url=https://archive.org/details/isbn_9780465071289 |title=Thousand mile song |publisher=Basic Books |year=2008 |isbn=978-0-465-07128-9 |url-access=registration}}</ref> The Paynes released the best-selling ''[[Songs of the Humpback Whale (album)|Songs of the Humpback Whale]]'' in 1970, and the whale songs were quickly incorporated into human music by, among others, singer [[Judy Collins]], as well as [[George Crumb]], [[Paul Winter]], and [[David Rothenberg]].

The humpback whale produces a series of repetitious sounds at varying frequencies known as whale song. Marine biologist Philip Clapham describes the song as "probably the most complex in the animal kingdom."<ref>{{cite book |author=Clapham, Philip |url=https://archive.org/details/humpbackwhales0000clap |title=Humpback whales |publisher=Colin Baxter Photography |year=1996 |isbn=978-0-948661-87-7 |url-access=registration}}</ref>

Male humpback whales perform these vocalizations often during the mating season, and so it was initially believed the purpose of songs is to aid mate selection.<ref name="Frankel" /> However, no evidence was found that links these songs to reprosexuality.{{citation needed|date=December 2024}}

The songs follow a distinct hierarchical structure. The base units of the song (sometimes loosely called the "[[note (music)|notes]]") are single uninterrupted emissions of sound that last up to a few seconds. These sounds vary in frequency from 20&nbsp;Hz to upward of 24&nbsp;kHz (the typical human range of hearing is 20&nbsp;Hz to 20&nbsp;kHz). The units may be [[frequency modulation|frequency modulated]] (i.e., the pitch of the sound may go up, down, or stay the same during the note) or [[amplitude modulation|amplitude modulated]] (get louder or quieter). However, the adjustment of bandwidth on a spectrogram representation of the song reveals the essentially [[Pulse (signal processing)|pulsed]] nature of the FM sounds.{{citation needed|date=December 2024}}

A collection of four or six units is known as a sub-[[phrase]], lasting perhaps ten seconds (see also [[phrase (music)]]).<ref name="Frankel" /> A collection of two sub-phrases is a phrase. A whale will typically repeat the same phrase over and over for two to four minutes. This is known as a theme. A collection of themes is known as a song.<ref name="Frankel" /> The whale song will last up to 30 or so minutes, and will be repeated over and over again over the course of hours or even days.<ref name="Frankel" /> This "[[Russian doll]]" hierarchy of sounds suggests a syntactic structure<ref>{{cite journal |last1=Suzuki |first1=R |last2=Buck |first2=JR |last3=Tyack |first3=PL |year=2006 |title=Information entropy of humpback whale songs |journal=J. Acoust. Soc. Am. |volume=119 |issue=3 |pages=1849–66 |bibcode=2006ASAJ..119.1849S |doi=10.1121/1.2161827 |pmid=16583924 |doi-access=free}}</ref> that is more human-like in its complexity than other forms of animal communication like bird songs, which have only linear structure.<ref>{{cite journal |last1=Berwick |first1=Robert C. |last2=Okanoya |first2=Kazuo |last3=Beckers |first3=Gabriel J.L. |last4=Bolhuis |first4=Johan J. |year=2011 |title=Songs to syntax: The linguistics of birdsong |journal=Trends in Cognitive Sciences |volume=15 |issue=3 |pages=113–121 |doi=10.1016/j.tics.2011.01.002 |pmid=21296608 |s2cid=17963919}}</ref>

All the whales in an area sing virtually the same song at any point in time and the song is constantly and slowly evolving over time.{{Citation needed|date=July 2009}} For example, over the course of a month a particular unit that started as an upsweep (increasing in frequency) might slowly flatten to become a constant note.<ref name="Frankel" /> Another unit may get steadily louder. The pace of evolution of a whale's song also changes—some years the song may change quite rapidly, whereas in other years little variation may be recorded.<ref name="Frankel" />

{{Wide image|Humpback song.PNG|1200px|Idealized schematic of the song of a humpback whale.<br/>Redrawn from Payne, et al. (1983)|600px|center|alt=Six long parallel lines with tick marks. "Song session (hours–days)" has no ticks. "Song (12–15 mins)" has 1 tick. "Theme (2 mins)" has 4 ticks. "Phrase (15–20 secs)" has 18 ticks. "Sub-phrase (7 secs)" has 36 ticks. "Unit (1 sec)" has many more ticks, this time angled up or down; it also has many gaps in the line.}}

[[File:Akhumps_128_016_0_500c.png|left|thumb|255px|alt=Two spectral images with X axis being time. In one, the Y axis is frequency and there is a complicated pattern in the 10–450 Hz region. In the other, the Y axis is amplitude, which is largely constant but with many small spikes.|Humpback whale, sound spectrum and time plots]]Whales occupying the same geographical areas (which can be as large as entire ocean basins) tend to sing similar songs, with only slight variations. Whales from non-overlapping regions sing entirely different songs.<ref name="Frankel" />

As the song evolves, it appears that old patterns are not revisited.<ref name="Frankel" /> An analysis of 19 years of whale songs found that while general patterns in song could be spotted, the same combination never recurred.{{Citation needed|date=July 2009}}

Humpback whales may also make stand-alone sounds that do not form part of a song, particularly during courtship rituals.<ref name="JMamm">{{cite journal |author=Mattila, David. K |author2=Guinee, Linda N. |author3=Mayo, Charles A. |year=1987 |title=Humpback Whale Songs on a North Atlantic Feeding Ground |journal=Journal of Mammalogy |volume=68 |issue=4 |pages=880–883 |doi=10.2307/1381574 |jstor=1381574}}</ref> Finally, humpbacks make a third class of sound called the feeding call.{{Citation needed|date=July 2009}} This is a long sound (5 to 10 s duration) of near constant frequency. Humpbacks generally feed cooperatively by gathering in groups, swimming underneath shoals of fish and all lunging up vertically through the fish and out of the water together. Prior to these lunges, whales make their feeding call. The exact purpose of the call is not known.

Some scientists have proposed that humpback whale songs may serve an [[animal echolocation|echolocative]] purpose,<ref>{{cite journal |author1=Mercado, E. III |author2=Frazer, L.N. |name-list-style=amp |year=2001 |title=Humpback whale song or humpback whale sonar? A Reply to Au et al. |url=http://www.acsu.buffalo.edu/~emiii/00946514.pdf |url-status=dead |journal=IEEE Journal of Oceanic Engineering |volume=26 |issue=3 |pages=406–415 |bibcode=2001IJOE...26..406M |citeseerx=10.1.1.330.3653 |doi=10.1109/48.946514 |archive-url=https://web.archive.org/web/20070614093521/http://www.acsu.buffalo.edu/~emiii/00946514.pdf |archive-date=14 June 2007}}</ref> but this has been subject to disagreement.<ref>{{cite journal |author1=W. W. L. Au |author2=A. Frankel |author3=D. A. Helweg |author4=D. H. Cato |name-list-style=amp |year=2001 |title=Against the humpback whale sonar hypothesis |journal=IEEE Journal of Oceanic Engineering |volume=26 |issue=2 |pages=295–300 |bibcode=2001IJOE...26..295A |doi=10.1109/48.922795}}</ref>

=== Other whale sounds ===
Humpback whales have also been found to make a range of other social sounds to communicate such as "grunts", "groans", "thwops", "snorts" and "barks".<ref>Cecilia Burke, '[http://www.australiangeographic.com.au/journal/a-whales-varied-vocabulary.htm 'A whale's varied vocabulary', Australian Geographic] {{Webarchive|url=https://web.archive.org/web/20100429155859/http://www.australiangeographic.com.au/journal/a-whales-varied-vocabulary.htm|date=29 April 2010}}, AG Online. Retrieved 7 August 2010.</ref>

In 2009, researchers found that [[blue whale]] song has been deepening in its tonal frequency since the 1960s.<ref>McDonald, Mark A., Hildebrand, John A., Mesnick, Sarah. [https://www.int-res.com/abstracts/esr/v9/n1/p13-21/ Worldwide decline in tonal frequencies of blue whale songs.] ''Endangered Species Research, Vol. 9 No. 1'' 23 October 2009.</ref> While [[noise pollution]] has increased ambient ocean noise by over 12 decibels since the mid-20th century, researcher Mark McDonald indicated that higher pitches would be expected if the whales were straining to be heard.<ref>Keim, Brandon. [https://www.wired.com/wiredscience/2009/12/blue-whale-song-mystery/ Blue Whale Song Mystery Baffles Scientists.] ''[[Wired (magazine)|Wired]].'' 2 December 2009.</ref>

Killer whales have been observed to produce long range calls that are stereotyped and high frequency travelling distances from {{cvt|10-16|km|mi}} as well as short range calls that can travel distances from {{cvt|5-9|km|mi}}. Short range calls are reported during social and resting periods while long range are more commonly reported during foraging and feeding.<ref>{{Cite journal |last=Miller |first=Patrick J. O. |date=2006-01-11 |title=Diversity in sound pressure levels and estimated active space of resident killer whale vocalizations |journal=Journal of Comparative Physiology A |language=en |volume=192 |issue=5 |pages=449–459 |doi=10.1007/s00359-005-0085-2 |issn=0340-7594 |pmid=16404605 |s2cid=22673399 |hdl-access=free |hdl=1912/532}}</ref>

Most other whales and dolphins produce sounds of varying degrees of complexity. Of particular interest is the [[Beluga (whale)|Beluga]] (the "sea canary") which produces an immense variety of whistles, clicks and pulses.<ref>{{cite web |author=ePluribus Media |title=The Canaries of the Sea, granted a pardon, this time… |url=http://discuss.epluribusmedia.net/node/2903 |url-status=dead |archive-url=https://web.archive.org/web/20091129143807/http://discuss.epluribusmedia.net/node/2903 |archive-date=29 November 2009 |access-date=7 August 2010}}</ref><ref name="seaworldcom">{{cite web |title=Beluga Whales – Communication and Echolocation |url=http://www.seaworld.org/infobooks/Beluga/becommunication.html |url-status=dead |archive-url=https://web.archive.org/web/20100619233228/http://seaworld.org/infobooks/Beluga/becommunication.html |archive-date=19 June 2010 |access-date=30 July 2010 |publisher=Sea World.org}}</ref>

It was previously thought that most baleen whales make sounds at about 15–20 [[hertz]].<ref name=":2">{{Cite web |last=Copley |first=Jon |title=Lonely whale's song remains a mystery |url=https://www.newscientist.com/article/dn6764-lonely-whales-song-remains-a-mystery/ |access-date=2021-10-24 |website=New Scientist |language=en-US}}</ref> However, a team of [[Marine biology|marine biologists]], led by Mary Ann Daher of the [[Woods Hole Oceanographic Institution]], reported in ''[[New Scientist]]'' in December 2004 that they had been tracking a whale in the North Pacific for 12 years that was "singing" at [[52-hertz whale|52 Hz]]. Scientists have been unable to explain this phenomenon. 52 Hz is a very low sound, it is audible through human ears as a low moaning sound.<ref>{{Cite web |date=2019-02-13 |title=How the world's loneliest whale inspired a kids tale about human connection |url=https://www.bigissue.com/culture/books/how-the-worlds-loneliest-whale-inspired-a-kids-tale-about-human-connection/ |access-date=2021-10-24 |website=The Big Issue |language=en}}</ref> It was not expected that this whale was a new species, more so this whale indicated that a currently known species potentially has a much wider vocal range than previously thought.<ref name=":2" /> There is disagreement in the scientific community regarding the uniqueness of the whale's vocalization and whether it is a member of a hybrid whale such as the well documented blue and fin whale hybrids.