The whistled language of La Gomera Island in the Canaries, the Silbo Gomero, replicates the islanders’ habitual language (Castilian Spanish) with whistling. Handed down over centuries from master to pupil, it is the only whistled language in the world that is fully developed and practised by a large community (more than 22,000 inhabitants). The whistled language replaces each vowel or consonant with a whistling sound: two distinct whistles replace the five Spanish vowels, and there are four whistles for consonants. The whistles can be distinguished according to pitch and whether they are interrupted or continuous. With practice, whistlers can convey any message. Some local variations even point to their origin.