Silbo Gomero

Silbo Gomero (Spanish: silbo gomero [ˈsilβo ɣoˈmeɾo], "Gomeran whistle"), also known as el silbo ("the whistle"), is a whistled register of Spanish used by inhabitants of La Gomera in the Canary Islands, historically used to communicate across the deep ravines and narrow valleys that radiate through the island. It enabled messages to be exchanged over a distance of up to five kilometres. Due to its loudness, Silbo Gomero is generally used for public communication. Messages conveyed range from event invitations to public information advisories. A speaker of Silbo Gomero is sometimes called a silbador ("whistler").

Silbo Gomero is a transposition of Spanish from speech to whistling. This oral phoneme-whistled phoneme substitution emulates Spanish phonology through a reduced set of whistled phonemes. In 2009, UNESCO declared it a Masterpiece of the Oral and Intangible Heritage of Humanity.