Headphones that turn down the volume on excess noise

A MAR BOSE WAS FRUSTRATED. It was 1978, and he’d planned to kill some of the time on his 6 000 km flight from Zurich to Boston by listening to music through some new, foam-covered (read: flimsy) headphones that Swissair supplied to the passengers. His enjoyment was foiled by the drone of the engines, which overpowered the lightweight headset.

Fortunately, Bose was a professor of electrical engineering at MIT, and the head of his own electronics company, the Bose Corporation. By the time he had arrived in