How does the brain compute sound localisation without the equations?
Some neuroscience papers on sound localization:


Joris Philip X, Smith Philip H, and Yin Tom C.T Coincidence Detection in the Auditory System // Neuron (1998)
Agmon-Snir Hagai, Carr Catherine E. and Rinzel John The role of dendrites in auditory coincidence detection // Nature (1998)
Trussell Laurence O. Synaptic mechanisms for coding timing in auditory neurons // Annual Review of Physiology (1999)
Grothe B., Pecka M., &amp; McAlpine D. Mechanisms of Sound Localization in Mammals // Physiological Reviews (2010) 
Chen X, Leischner U, Rochefort NL, Nelken I, Konnerth A. Functional mapping of single spines in cortical neurons in vivo // Nature (2011) 


Books


Blauert, J.: Spatial hearing: the psychophysics of human sound localization; MIT Press (1983)
Schnupp, Nelken and King: Auditory Neuroscience: Making Sense of Sound, MIT Press, 2011