Silbo

You may not know but in the Island of La Gomera people can communicate with themselves by a whistling language- Silbo.

 

Years ago, before the arrival of Spanish settlers in XVI century to the Island, the original inhabitants- Guanches- were using this kind of language. It was a normal communication method in mountainous areas.

Now the language is adapted to the sound of Spanish language and it has 2 vowels and 4 consonants.

To prevent the extinction of Silbo, the government of Gomera  introduced the language to Gomeran schools.

You can watch and read more here.