Songs from Silence

Lang Elliott didn't realize the birdsong he was missing until the Worm-eating Warbler incident. In the 1970s, a professor noted the bird, but even standing beneath it, Elliott couldn't pick out its lusty, high trills. This "ear-opener" led to an experiment: Elliott slowed the speed--and lowered the pitch--of a recording he took in a forest. He was shocked at the birds he heard. A test revealed Elliott, then 27, had high-frequency hearing loss, a condition caused by loud sounds or aging that one study found may affect nearly a third of US adults under 70.