Unavoidably Delayed: A Personal Perspective of Twenty Years of Research on a Sound Localization Cue
Localization of sound sources depends on a variety of cues, the most important of which are the differences in sound level and arrival time at the two ears. The differences in the arrival time are only of the order of millionths of seconds, and more than 60 years ago a putative neural mechanism to decipher these tiny differences was proposed by Lloyd Jeffress. Jeffress’s model has stood the test of time, with most of its essential elements (an internal delay before comparison of the input from the two ears by a coincidence mechanism) essentially now taken as established fact. However, over the last 20 years or so there has been renewed interest in the processes by which the tiny time differences are decoded, in particular in the preprocessing of the timing information and in the mechanism that generates the internal delay. These issues are still not fully resolved, as will be clear from this short and personal perspective.
KeywordsSuperior Colliculus Delay Line Inferior Colliculus Interaural Time Difference Interaural Level Difference
I am really grateful to Trevor Shackleton and Adrian Rees for casting a critical eye over this piece of writing which, to be honest, is a little outside my usual comfort zone.
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