Whistled language

A whistled language is the use of whistling to emulate speech and facilitate communication. Generally whistled languages emulate the intonation, tones or vowel formants, and prosody of a natural language so that speakers of that language can recognize the speech melody of what is being said and thus understand the whistled speech. Whistled language is rare compared to spoken language, but it is found in cultures around the world. It is especially common in tonal languages where the whistled tones follow the tones of the syllables (tone melodies of the words), probably because it is easier for a "whistlized" form to develop in a tonal language than a non-tonal, especially if the non-tonal one with a large phonemic inventory. The genesis of a whistled language has never been recorded in either case and had not yet received much productive study.

Techniques
Whistled languages differ according to whether the spoken language is tonal or not, with the whistling being either tone or articulation based.

Tonal languages are often stripped of articulation, leaving only suprasegmental features such as duration and tone, and when whistled retain the spoken melodic line. Thus whistled tonal languages convey phonemic information solely through tone, length, and, to a lesser extent, stress, and most segmental phonemic distinctions of the spoken language are lost.

In non-tonal languages, more of the articulatory features of speech are retained, and the normally timbral variations imparted by the movements of the tongue and soft palate are transformed into pitch variations (Busnel and Classe 1976: v). Certain consonants can be pronounced while whistling, so as to modify the whistled sound, much as consonants in spoken language modify the vowel sounds adjacent to them.

"All whistled languages share one basic characteristic: they function by varying the frequency of a simple wave-form as a function of time, generally with minimal dynamic variations (but see Cowan 1948 see Mazateco), which is readily understandable since in most cases their only purpose is long-distance communication." (Busnel and Classe 1976: 32)

Different whistling styles may be used in a single language. Sochiapam Chinantec has three different words for whistle-speech: sie3 for whistling with the tongue against the alveolar ridge, jui̵32 for bilabial whistling, and juo2 for finger-in-the-mouth whistling. These are used for communication over varying distances. There is also a kind of loud falsetto (hóh32) which functions in some ways like whistled speech.

The expressivity of whistled speech is likely to be somewhat limited compared to spoken speech (although not inherently so), but such a conclusion should not be taken as absolute, as it depends heavily on various factors including the phonology of the language. For example in some tonal languages with few tones, whistled messages typically consist of stereotyped or otherwise standardized expressions, are elaborately descriptive, and often have to be repeated. However, in languages which are heavily tonal, and therefore convey much of their information through pitch even when spoken, such as Mazatec and Yoruba, extensive conversations may be whistled. In any case, even for non-tonal languages, measurements indicate that high intelligibility can be achieved with whistled speech (90% of intelligibility of non-standardized sentences for Greek (Meyer 2005) and the equivalent for Turkish (Busnel 1970).)

In continental Africa, speech may be conveyed by a whistle or other musical instrument, most famously the "talking drums". However, while drums may be used by griots singing praise songs or for inter-village communication, and other instruments may be used on the radio for station identification jingles, for regular conversation at a distance whistled speech is used. As two people approach each other, one may even switch from whistled to spoken speech in mid-sentence.

Examples
The Silbo on the island of La Gomera in the Canary Islands, maintains the five vowels of Spanish, but reduces its consonants to four.

Other whistled languages exist or existed in such parts of the world as Turkey (Kusköy, "Village of the Birds"), France (the village of Aas in the Pyrenees), Mexico (the Mazatecs and Chinantecs of Oaxaca), South America (Pirahã), Asia (the Chepang of Nepal), and New Guinea. They are especially common and robust today in parts of West Africa, used widely in such populous languages as Yoruba and Ewe. Even French is whistled in some areas of western Africa.

Usage and cultural status
In the Greek village of Antia, only few whistlers remain now (Meyer 2005) but in 1982 the entire population knew how to whistle their speech.

Whistled speech may be very central and highly valued in a culture. Shouting is very rare in Sochiapam Chinantec. Men in that culture are subject to being fined if they do not handle whistle-speech well enough to perform certain town jobs. They may whistle for fun in situations where spoken speech could easily be heard.

In Sochiapam and other places in Mexico, and reportedly in West Africa as well, whistled speech is men's language: although women may understand it they do not use it.

Though whistled languages are not secret codes or secret languages (with the exception of a whistled language used by ñañigos terrorists in Cuba during Spanish occupation (Busnel and Classe 1976: 22)), they may be used for secretive communication among outsiders or others who do not know or understand the whistled language though they may understand its spoken origin. Stories are told of farmers in Aas during World War II, or in La Gomera, who were able to hide evidence of such nefarious activities as milk-watering because they were warned in whistle-speech that the police were approaching (Busnel and Classe 1976: 15).

Ecology
Whistled languages are normally found in locations with difficult mountainous terrain, slow or difficult communication, low population density and/or scattered settlements, and other isolating features such as shepherding and cultivation of hillsides (Busnel and Classe 1976: 27 – 28). The main advantage of whistling speech is that it allows the speaker to cover much larger distances (typically 1 – 2 km but up to 5 km) than ordinary speech, without the strain (and lesser range) of shouting. The long range of whistling is enhanced by the terrain found in areas where whistled languages are used. Many areas with such languages work hard to preserve their ancient traditions, in the face of rapidly advancing telecommunications systems in many areas.

Physics
A whistled tone is essentially a simple oscillation (or sine wave), and thus timbral variations are impossible. Normal articulation during an ordinary lip-whistle is relatively easy though the lips move little causing a constant of labialization and making labial and labiodental consonants (p, b, m, f, etc.) problematical(Busnel and Classe 1976: 3). "Apart from the five vowel-phonemes [of Silbo Gomero] — and even these do not invariably have a fixed or steady pitch — all whistled speech-sound realizations are glides which are interpreted in terms of range, contour, and steepness." (Busnel and Classe 1976: 8)

In a non-tonal language, segments may be differentiated as follows:
 * Vowels are replaced by a set of relative pitch ranges generally tracking the f2 formant of spoken language.
 * Stress is expressed by higher pitch or increased length
 * Consonants are produced by pitch transitions of different lengths and height, plus the presence or absence of occlusion. ("Labial stops are replaced by diaphragm or glottal occlusions.")

In the case of Silbo Gomero, such strategies produce five vowels and four consonants.

List of whistled languages and speaking ethnic groups
The following list is of languages that exist or existed in a whistled form, or of ethnic groups that speak such languages. In some cases (e.g. Chinantec) the whistled speech is an important and integral part of the language and culture; in others (e.g. Nahuatl) its role is much lesser.
 * Americas
 * Mexico: Amuzgo, Chinantec, Ch'ol, Kickapoo, Mazatec, Nahuatl, Otomi, Tepehua, Totonac, Zapotec.
 * Bolivia: Siriono
 * Brazil: Pirahã
 * Alaska: Yupik
 * Asia
 * Myanmar: Chin
 * Nepal: Chepang
 * Turkey: Kuskoy
 * Europe
 * France (village of Aas, Pyrenees): Occitan language
 * Greece (village of Antia on the island of Euboea)
 * Spain (La Gomera, Canary Islands): "Silbo Gomero"
 * West Africa: Bafia, Bape, Birifor, Bobo, Burunsi, Daguri, Diola, Ewe, Fongbe, Marka, Ngwe, Twi, Ule (among others).
 * Oceania
 * New Guinea: Gasup, Binumarien