Editing Larynx (section)

==Other animals==
[[File:Kehlkopf Pferd.jpg|thumb|160px|Cut through the larynx of a horse<br />
(frontal section, posterior view)<br />1&nbsp;[[hyoid bone]]; 2&nbsp;[[epiglottis]]; 3&nbsp;[[vestibular fold]]; 4&nbsp;[[vocal fold]]; 5&nbsp;[[ventricularis muscle]]; 6&nbsp;[[ventricle of larynx]]; 7&nbsp;[[vocalis muscle]]; 8&nbsp;[[thyroid cartilage]]; 9&nbsp;cricoid cartilage; 10&nbsp;[[infraglottic cavity]]; 11&nbsp;first [[tracheal]] cartilage; 12 [[trachea]]]]
Pioneering work on the structure and evolution of the larynx was carried out in the 1920s by the British comparative anatomist [[Victor Negus]], culminating in his monumental work ''The Mechanism of the Larynx'' (1929). Negus, however, pointed out that the descent of the larynx reflected the reshaping and descent of the human tongue into the pharynx. This process is not complete until age six to eight years. Some researchers, such as [[Philip Lieberman]], [[Dennis Klatt]], [[Bart de Boer]] and [[Kenneth N. Stevens|Kenneth Stevens]] using computer-modeling techniques have suggested that the species-specific human tongue allows the vocal tract (the airway above the larynx) to assume the shapes necessary to produce speech sounds that enhance the robustness of human speech. Sounds such as the vowels of the words {{angle bracket|see}} and {{angle bracket|do}}, [i] and [u] (in phonetic notation), have been shown to be less subject to confusion{{Compared to?|date=August 2022}} in classic studies such as the 1950 Peterson and Barney investigation of the possibilities for computerized [[speech recognition]].<ref name="Lieberman">{{Harvard citation no brackets|Lieberman|2006}}</ref>

In contrast, though other species have low larynges, their tongues remain anchored in their mouths and their vocal tracts cannot produce the range of speech sounds of humans. The ability to lower the larynx transiently in some species extends the length of their vocal tract, which as Fitch showed creates the acoustic illusion that they are larger. Research at Haskins Laboratories in the 1960s showed that speech allows humans to achieve a vocal communication rate that exceeds the fusion frequency of the auditory system by fusing sounds together into syllables and words. The additional speech sounds that the human tongue enables us to produce, particularly [i], allow humans to unconsciously infer the length of the vocal tract of the person who is talking, a critical element in recovering the [[phoneme]]s that make up a word.<ref name="Lieberman" />

===Non-mammals===
Most [[tetrapod]] species possess a larynx, but its structure is typically simpler than that found in mammals. The cartilages surrounding the larynx are apparently a remnant of the original [[gill arch]]es in fish, and are a common feature, but not all are always present. For example, the thyroid cartilage is found only in mammals. Similarly, only mammals possess a true [[epiglottis]], although a flap of non-cartilagenous [[mucosa]] is found in a similar position in many other groups. In modern amphibians, the laryngeal skeleton is considerably reduced; [[frog]]s have only the cricoid and arytenoid cartilages, while [[salamander]]s possess only the arytenoids.<ref name=VB>{{Harvard citation no brackets|Romer|Parsons|1977|pp=214–215, 336}}</ref>

An example of a frog that possesses a larynx is the [[túngara frog]]. While the larynx is the main sound producing organ in túngara frogs, it serves a higher significance due to its contribution to mating call, which consist of two components: 'whine' and 'chuck'.<ref>{{cite journal |last1=Ryan |first1=Michael J |last2=Guerra |first2=Mónica A |title=The mechanism of sound production in túngara frogs and its role in sexual selection and speciation |journal=Current Opinion in Neurobiology |date=1 October 2014 |volume=28 |pages=54–59 |doi=10.1016/j.conb.2014.06.008 |pmid=25033110 |s2cid=14153228 |url=https://doi.org/10.1016/j.conb.2014.06.008 |language=en |issn=0959-4388}}</ref> While 'whine' induces female phonotaxis and allows species recognition, 'chuck' increases mating attractiveness.<ref name="ryan">{{cite journal |last1=Ryan |first1=M. J. |title=Túngara Frog: A Model for Sexual Selection and Communication |journal=Encyclopedia of Animal Behavior |date=1 January 2010 |pages=453–461 |doi=10.1016/b978-0-08-045337-8.00033-4 |url=https://doi.org/10.1016/B978-0-08-045337-8.00033-4 |publisher=Academic Press |isbn=9780080453378 |language=en}}</ref> In particular, the túngara frog produces 'chuck' by vibrating the fibrous mass attached to the larynx.<ref name="ryan" />

Vocal folds are found only in mammals, and a few [[lizard]]s. As a result, many reptiles and amphibians are essentially voiceless; frogs use ridges in the trachea to modulate sound, while [[bird]]s have a separate sound-producing organ, the [[Syrinx (biology)|syrinx]].<ref name=VB/>