Neuron 65, 412–421 (2010)

Hearing a sound stop is just as important as hearing it start, but how the auditory system processes the end of a sound has been unclear.

Michael Wehr and his colleagues at the University of Oregon in Eugene recorded activity in the brains of rats while playing tones to the animals. The researchers found that individual neurons respond to the beginning of tones at certain frequencies but respond to the end of tones at very different frequencies, so one neuron could not register 'on' and 'off' for the same tone.

The results suggest that the brain must integrate activity in separate neurons to register the beginning and end of a sound.