Whistling

Brazil's Amazonian Pirahã people whistle to communicate while hunting. Because the Pirahã Language has so few consonants and vowels that pitch, length, and stress alone carry meaning, hunters can swap signals by whistling instead of speaking and startling prey.

On La Gomera in Spain's Canary Islands, a whistled Language called 'Silbo Gomero' turns Spanish into whistles. It blurs sounds together, but as tones carry over a narrow frequency band, they travel farther — letting people converse across steep valleys up to 5 km apart.