Editing Whistled language (section)

==== Tonal whistle languages and types of tones ====

Only the tone of the speech is saved in the whistle, while aspects as articulation and phonation are eliminated. These are replaced by other features such as stress and rhythmical variations. However, some languages, like that of the [[Zezuru]] who speak a [[Shona language|Shona]]-derived dialect, include articulation so that consonants interrupt the flow of the whistle. A similar language is the [[Tsonga language|Tsonga]] whistle language used in the highlands in the Southern parts of [[Mozambique]]. This should not be confused with the [[whistled sibilant]]s of Shona.

There are two different types of whistle tones - [[Physics of whistles#Hole|hole tones]] and [[Physics of whistles#Edge tone|edge tones]]. A hole (or 'orifice') tone is produced by a fast-moving cylinder (or 'vena contracta') of air that interacts with the slow-moving anulus of air surrounding it.<ref name=Shosted2006>{{cite journal |last1=Shosted |first1=Ryan K. |title=Just Put Your Lips Together and Blow? The Whistled Fricatives of Southern Bantu |journal=UC Berkeley PhonLab Annual Report |date=2006 |volume=2 |issue=2 |url=https://escholarship.org/uc/item/3p19w08r}}</ref> Instability in the boundary layer leads to perturbations that increase in size until a feedback path is established whereby specific frequencies of the resonance chamber are emphasized.<ref>{{cite journal |last1=Shadle |first1=Christine H. |title=Experiments on the acoustics of whistling |journal=The Physics Teacher |date=March 1983 |volume=21 |issue=3 |pages=148–154 |doi=10.1119/1.2341241 |bibcode=1983PhTea..21..148S}}</ref> An edge tone, on the other hand, is generated by a thin jet of air that strikes an obstacle. Vortices are shed near the point of disturbance in the flow, alternating on each side of the obstacle or 'wedge'.<ref name=Shosted2006/>

One of the best-studied whistled languages is a whistled language based on Spanish called [[Silbo Gomero language|Silbo]], whistled on the island of [[La Gomera]] in the [[Canary Islands]] ([[Annie Rialland|Rialland]] 2005). The number of distinctive sounds or phonemes in this language is a matter of disagreement, varying according to the researcher from two to five vowels and four to nine consonants. This variation may reflect differences in speakers' abilities as well as in the methods used to elicit contrasts. The work of Meyer<ref name=Meyer2005/><ref name=Meyer2008/> clarifies this debate by providing the first statistical analyses of production for various whistlers as well as psycholinguistic tests of vowel identification.