A device that detects ear-pressure changes -- to determine how a person is moving their tongue -- should let people with extremely restricted movement control a wheelchair or computer more easily.

However, some improvements are needed before tongue movements can be detected when a person is active. "If you are running or moving around, the bones of your skull conduct too much noise," says Vaidyanathan, "but I think improving the design of the earplug and the mathematical signal processing could address that in future."