Audio localization accuracy with two microphones
Each ear have a Frequency Response $H_L(f)$ and $H_R(f)$ and transmission delays $\tau_L$ and $\tau_R$ according the 3D angle from where the sound source is located relative to each ear. 

Hence, for a fixed magnitude and frequency sound, $s(t)$, you have the response $H_L(f)s(t-\tau_L)$ and $H_R(f)s(t-\tau_R)$.

Actually, you cannot solve this for every position, or equivalently, you need a head movement (or ear movement in animals) for retrieving the proper angle. Besides, there exist some cone of confusion which means there is actually not a well defined 3D angle, mainly you only can locate 2D cones instead of location.

I will not solve it for you, but from that information you can trivially determine a location considering head movement onto some estimated direction, or an enough rich movement trajectory.