The Jeffress' model is a model of a neural circuit built to detect the direction that a sound is coming from. It's a beautiful and elegant model that has been found to be used by the brains of many different species, including humans. One of the most elegant bodies of work in neuro-ethology showed that this model holds for barn owls and explore many of the nuances of the behaviour.
The work of many people mainly Knudsen and Konishi and Catherine Carr showed that not only is the Jeffress model used to compute the azimuth but it also is used at several frequencies after a sound has been decomposed into different frequency components. This solves the problem of degenerate solutions that you could get from a pure tone sound. Apart from this, in perhaps one of the most 'awww' experiments ever, they showed that the auditory map is tuned to the visual map and this can be tuned and retuned but only when owls are young. It's beautiful work and this piece is in based on it. Imagine trying to sneak up on these owls as they were hunting and imagine that they found you instantly as you rustled through the teasels. They would find you with an accuracy of a single degree!