International project aims to decode whale communication

Listening to our animal kin — some experts predict that the capacity and technology to understand and talk back to non-human mammals will be developed by the end of the decade, just a few short years away

Sperm whales swimming off the coast of Dominica. The marine mammals have a complex communication system that scientists are working to decode. Picture: Amanda Cotton / Project CETI

Whales live in a world of sound. Not only are whales the largest animals on the planet, they’re also among the loudest.

Because seawater is much denser than air, sound travels both faster and farther underwater. Light fades quickly at depth, leaving visibility poor, so whales effectively 'see' with sound — reliant on clicks, whistles, pulses, and low-frequency calls to navigate, hunt, coordinate group behaviour, and maintain social bonds. The calls they emit can travel extraordinary distances through the ocean. Vocalisations are often complex and species-specific, much like birdsong, though resonate at far deeper pitches.