The whistled languages
All over the world some populations have developped a whistled form of their language which is called "whistled language" or whistled speech because they use the modulations of the whistles instead of the vibrations of vocal cords to encode the complexity of a local language. They allow communications at longer distances than the spoken voice as in the Pyrenees, the island of La Gomera in the Canary islands or in Turkey. They also ease hunting in forests like in the Amazone forest, they are also used for courtship conversations in South east Asia (Hmong language for example).
You can listen sound examples
|Whistled Béarnais in the Aas village of the French Pyrenees||The "Silbo" whistled spanish of the Canary islands|
|The forms of whistled speech of Mazatec of Mexico||The whistled Turk in Kuskoy, Turkey|
|The whistled Greek in the island of Eubea, Greece|
More details in scientific publications.