Understanding sound localisation

The Inaugural Deafness Research UK UCLEI Postgraduate Studentship was awarded to Jason Mikiel-Hunter to work with Professor David McAlpine at the UCL Ear Institute in London.

[Studentship: 2005-2009]

Being able to know quickly just where a sound is coming from is one of the most important tasks of the auditory system. Many situations, from understanding conversation in noisy environments to crossing the road safely, benefit from accurate sound localisation. It has long been known that the brain compares tiny differences between the time at which sound arrives at one ear compared to the other, but exactly how it makes that comparison is still being understood.

Recent evidence has shown that neurons in a key part of the hearing pathway are sensitive to the time differences between sounds at the two ears. The aim of the project is to find out how these neurons control the timing of the signals they send to communicate with other cells. Understanding how this is done will give us fundamental knowledge of the hearing system, which in turn will help us understand what happens if the system stops working and so improve the options for treatment.

The initial part of the project has focused on comparing cells that respond to high sound frequencies with those that respond to lower frequencies. More is known about how low frequency cells convey timing information and so the team is currently investigating whether this information can be represented in the same way by high frequency cells, despite differences in the way the two groups of cells respond to sounds.