Complete the notes below. Choose ONE WORD ONLY from the passage for each answer.

Silbo Gomero

How Silbo is produced

• high- and low-frequency tones represent different sounds in Spanish [7]

• pitch of whistle is controlled using silbador’s [8]

• [9] is changed with a cupped hand

How Silbo is used

• has long been used by shepherds and people living in secluded locations

• in everyday use for the transmission of brief [10]

• can relay essential information quickly, e.g. to inform people about [11]

The future of Silbo

• future under threat because of new [12]

• Canaries’ authorities hoping to receive a UNESCO [13] to help preserve it