WHALES have a cunning way of filtering the sound of their own “voice” out of their echolocation systems, to help them navigate and locate prey.
The “clicks” that whales produce for echolocation are loud, while the echoes that bounce back are faint. Alexander Supin of the Russian Academy of Sciences in Moscow wondered how they hear the echoes above the noise of their outgoing clicks. To find out, his team placed a suction-cup electrode near the blowhole of a false killer whale (Pseudorca crassidens). This eavesdropped on electrical signals in the whale’s brain stem. The team found that the original click and the echo evoked the same strength of brain-stem response (The…
