Silbo

Canary Islands - 

Where phones and computers are a disease.

In a Word

tongue-shot
n. speaking or talking distance, voice-range

Inhabitants of La Gomera, a small mountainous island in the Canary group, use a whistled language called the Silbo to communicate over great distances. “This is a form of telephony inferior to ours as regards range, but superior to it in so far as the only apparatus required is a sound set of teeth and a good pair of lungs,” noted Glasgow University phoneticist André Classe in New Scientist in 1958. “The normal carrying power is up to about four kilometres when conditions are good, over twice as much in the case of an exceptional whistler operating under the most favourable circumstances.”

The Futility Closet