The Chant S of the Baleine S are sounds emitted by these Cétacé S to communicate between them. One speaks about “songs”, to describe the repetitive and foreseeable impression of these messages, which depend on the Espèce of the whale which emits them.

The biological process, which makes it possible the animal to produce these sounds depends on the family to which it belongs. However, all the whales, the Dolphin S and the Orque S use these sounds like Sonar S to locate itself under water. Indeed, the light is not almost present any more at great depths, and this tool allows them an effective representation of their environment. According to some ecologist S, the increase in the noise in the oceans, mainly because of the human machines, interferes with these sounds and misleads the animal: and often, this error is fatal for him.

Production of sound

At the human ones, the sounds are produced in the following way. The pulmonary air expired crosses the Larynx where the vocal cords are. Those while opening and closing themselves segment the airstream in a succession of puffs which are then worked by the throat, the Langue and the Lèvre S to form the desired sounds.

In the Cetacea, the production of sounds results from other processes. The mechanism is besides different at the Odontocète S (whales with teeth, including the dolphins) from the Mysticète S (whales with pennons, including the largest whales, such as for example the Blue whale).

Emission of the sound in the Cetacea Odontocète S

The whales with teeth do not produce the sounds of low frequencies known under the name of song of the whales . In the place, they produce fast bouquets of rattling and high frequency whistles. The isolated clicks are in general used for the echolocation whereas the series of rattling and whistles are used to communicate. Although the dolphins produce when they are in group true a Cacophonie of varied sounds, the significance of these sounds remains mysterious. Frankell (1998) quotes a researcher who compares the noise produced by a group of dolphins with that done by children in a playground.

The various sounds are produced by the passage of the air through an anatomical structure located in the head, called phonic lips ( phonic lips ) or muzzle of monkey , comparable with the nasal Voies human. When the air borrows this narrow conduit, it causes, with the manner of the human whirrs, the aspiration and the joining of the phonic lips and the setting in vibration of surrounding fabrics, with emission of a sound. The vibration can, just like the man does it with his larynx for the voice, being voluntarily controlled by the animal with much precision. For echolocation, the vibration crosses cranial fabrics until the melon, a kind of case of resonance which forms and directs the sound beam. All the whales with teeth, except the Cachalot have two pairs of phonic lips and can thus emit two sounds independently. The air which passed the phonic lips enters the vestibular bag. From there, it can be expelled outside by the vent or be returned in the lower part of the apparatus nasal and recycled to emit a new sound.

Recent cranial analyzes using the techniques of axial Tomography and tomography per single emission of photon showed, at least in the case of the Grand Dolphin, that the air could be conveyed with the nasal apparatus since the lungs by the Sphincter palatopharyngien, allowing the sound creative process of to continue as a long time as the animal was able to retain its breathing (To cover and Al , 2004).

Emission of the sound in the Cetacea Mysticète S

The whales do not have a structure of the type muzzle of monkey (phonic lips). Their Larynx seems to play a part during the sound production, but they do not have vocal cords and the exact mechanism remains obscure. The process, however, is not completely similar to that of the man because the whales produce sounds without expiring. It is probable that they use air in closed circuit. The cranial sines can also be used to create sounds, but the researchers yet clearly did not explain the process.

The goal of the sound production of the Cetacea

Contrary to throbbing and complex songs of the humpback whales (and certain blue whales), of which the supposed goal is initially the selection of the sexual partner (see below), the simpler sounds of the other Cetacea have a constant utility. Although the whales with teeth (including the Orc) are able to use the echolocation (directional emission of ultrasounds) to very precisely detect the size and the nature of the objects, the whales with pennons do not have this capacity. Moreover, contrary to certain fish, like the Shark S, the sense of smell of the whales is not very developed. The audible sounds by the man play a part in navigation in their medium where the visibility is low and where the sound is propagated well. For example, the depth to which the large obstacles can be detected by the powerful sounds emitted by the whales with panonstus.

Song of the Humpback whale

Two groups of whales, the humpback whales and the blue whales of the Indian Ocean, are known to emit repetitive sounds at various frequencies, which one calls the “song of the whales”. Philip Clapham (1996), marine Biologist states-unien, described this sound like “most complex of the animal kingdom”.

The male humpback whales are exerted with this song only during the season of the loves, and it is possible that these sounds have an impact on the sexual selection of the partners. However, we do not have so much information, in spite of work on the subject, and the study of this assumption is prone to many current research.

The researchers Roger Payne and Scott McVay have the first analyzed these songs in 1971. These sounds follow a very distinct hierarchical structure. The basic unit (sometimes called note ) is a continuous sound of variable frequency, between 20 Hz and 10 Khz, which lasts of one at a few seconds. The human being can perceive only the sounds whose frequency varies between 20 Hz and 20 Khz, with the result that they are perfectly audible for us without equipment. The variation of frequency during a note can be a frequency modulation : towards the acute one, the low register, without change of power; or a amplitude modulation : more extremely, less extremely or with the same sound volume. What makes a total of 9 sound units.

A succession from 4 to 6 units forms a under-sentence, and lasts approximately 10 seconds. At least two under-sentences form a sentence. A whale generally repeats the same sentence during 2 to 4 minutes, which one calls a topic . A continuation of topics form a song. The whales can repeat this song - which lasts approximately 20 minutes - during hours, even of the whole days. This linguistic hierarchy in “Russian headstocks” captivated the attention of the researchers.

Moreover, with time, the song of a whale evolves/moves. For example, a note which in the beginning increased its frequency (“upsweep”) becomes, progressively of the songs, a telling note, another note can become stronger (“louder”). In addition to these some variations, others settle with the age of the animal, during the months or of the years. The whales which live on the same part of the sphere have similar songs - outwards, even the notes are completely different. But logic remains the same one.

A study over 19 years proved that the sound of the whales never makes “flashback”: a song which evolved/moved continues to evolve/move, the old songs are never thereafter marked.

The humpback whales also emit isolated sounds, which do not belong to a song.

Lastly, a third category of song is the call to the meal (“feeding cal”). It is a relatively long song (5 to 10 seconds) of a frequency and a constant amplitude. The humpback whales generally nourish all units, while gathering to attack the fish benches. The exact reason of the emission of this song is still unknown, but it is possible that the fish recognize it. Indeed, when one passes by again using a material adapted the call to the meal of a whale, the fish flee with the other end of the basin, although there is no whale.

Other songs of the whales

The other whales emit sounds between 15 and 20 hertz. However, of the marine biologists with the Woods Hole Oceanographic Institution deferred in the New Scientist in December 2004 that they had followed a whale in the Northern Pacific during 12 years which “had sung” to 52 Hz. The scientists are currently unable to explain this important difference compared with the songs observed hitherto. However, they affirm that the animal at the origin of the sounds was well a whale, of a known species, suggesting whereas we probably underestimate the vocal capacity of these animals.

The majority of the whales and the dolphins emit sounds of a variable complexity. The white whale (or “marine canary”) is particular for its punctuated songs of whistles, clis and varied pulsations.

Human interactions

Although certain people consider that one carries too interest to the whales under pretext that they are marine animals, the majority of the scientists agree to say that these songs have a headlight role in the life of these Cetacea, in their social relations, their development and in their food. Some critical consider that is to humanize an animal behavior to consider a direction with these songs, comparing them for example to lowings of the cattle.

The researchers use Hydrophone S (often used at the origin in a military use to track the submarines) to make sure of the exact position of the origin of the sounds, allowing to detect them even at long distances. The research carried out by Doctor Christopher Clark of the Université of Cornell gathering military data accumulated during 30 years shows that the song of the whales moves on more than 3000 km. In addition to the information thus deduced on the production from the sounds in the Cetacea, these observations have permi a better approach of the migratory way of the whales during the season of the loves - which also proves to be the season of the songs.

Clark supports that, before the man does not come to disturb the surface of the oceans, the songs of the whales could probably cross the oceans of an end to the other. Its research proposes the fact that the noise ambient Sous-marin generated by the man (boats, submarines…) double every decade. That largely affects the clearness and the transmission of the sounds emitted by the Cetacea - some advance even the assumption that this phenomenon would disorientate the Cetacea, which would then come to fail themselves on the beaches. The other research, led to the Canada, proved that near an important sea traffic, for example off the town of Vancouver, the Orque S adapt their frequency, increase the amplitude of their songs so that they are better audible. Sound pollution, while limiting the communication between these animals, returns the search for a more difficult partner.

See too

To listen to the whales

References

• Lone whale' S song remains has mystery , New Scientist , n° 2477, December 11th, 2004
• Sound production, Adam S. Frankell, Encyclopedia off Marine Mammals (PPP 1126-1137) ISBN 0125513402 (1998)
• In search off pulse sound sources in odontocetes of Ted Cranford in Hearing by Whales and Dolphins (W. Lu, A. Popper and R. Fays eds.). Springer-Verlag (2000).
• Progressive exchanges in the songs off Humpback Whales (Megaptera novaeangliae): detailed analysis off two has seasons in Hawaii by K.B.Payne, P. Tyack and R.S. Payne in Communication and behavior off whales . Westview Close (1983)
• BBC News , February 28th, 2005. Unweaving the song off whales
• Humpback Whales , by Phil Clapham ISBN 0948661879
• Structural and functional imaging off bottlenose dolphin (Tursiops truncatus) cranial anatomy , by Dorian S. Houser, James Finneran, Gift To card, William Van Bonn, Cynthia Smith, Carl Hoh, Robert Mattrey and Sam Ridgway, Newspaper off Experimental Biology Volume = 207

External bonds

• Research on the communication between whales at the University of Cornell

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