Various instances of whistled speech are known around the world. These are not separate languages but rather translations of the phonemes of the local language into whistling sounds. In most instances the whistling is done with the mouth alone, but in Africa a whistle is used. As the expressivity of whistle sounds is limited compared to ordinary speech, whistled messages are typically short and standard and often have to be repeated.
The main advantage of whistling speech is that it allows to cover much larger distances (typically 1-2 km but up to 5 km) than ordinary speech. These speeches are usually found in areas with low population density and difficult terrain.
The following languages exist or existed in a whistled form: