Sound source localization uses interaural time difference (ITD) or interaural intensity difference cues, and most of the methods based on ITD are limited by the aperture of array. However, a kind of parasitoid fly called Ormia ochracea with coupled ears has a remarkable ability to localize calling of crickets regardless of the fly's small body size. The structure of fly's ear is generalized, and a multi-dimensional coupled system with an acoustic sensor array is proposed. The magnification factor of the phase difference in this system, which can be used to describe the ITD changes of signals from the coupled system, is chosen as the kernel parameter to measure the effect of coupling. The coupled system is optimized by choosing appropriate physical parameters such that the degree of magnification does not vary with angle of incidence. The simulation results demonstrate that the time delay between two signals increases by the coupled system, and the magnification factor remains stable as expected. Compared with the traditional general cross-correlation method, the localization error of the coupled system is reduced.