It has been known for a long time that this ability depends on tiny differences in the sounds that arrive at each ear, including differences in the time of arrival: in humans, for example, sound will arrive at the ear closer to the source up to half a millisecond earlier than it arrives at the other ear. For example, barn owls can snatch their prey in complete darkness by relying on sound alone. Having two ears allows animals to localize the source of a sound. These estimates can still be obtained when only contralateral neural responses are used, consistently with unilateral lesion studies.

We demonstrate that there is insufficient information in the pooled activity of each hemisphere to estimate sound direction in a reliable way consistent with behavior, whereas robust estimates can be obtained from neural activity by taking into account the heterogeneous tuning of cells. We tested the performance of various decoders of neural responses in increasingly complex acoustical situations, including spectrum variations, noise, and sound diffraction. In the auditory brainstem, a recent theory proposes that sound location in the horizontal plane is decoded from the relative summed activity of two populations in each hemisphere, whereas earlier theories hypothesized that the location was decoded from the identity of the most active cells. This may be extracted from neural activity using different strategies. The activity of sensory neural populations carries information about the environment.

Goodman model number decoding