Is the cochlea coiled to provide sound localization?

The potential physical effect of the cochlear shape on sound localization is studied from the perspective of signal processing. The sensory hair cells are taken to form a sensor array, and a numerical model is used to simulate the external sound pressure perceived by the sensory hair cells directly, that is, via bone conduction. The cognitive process is thus approximated as a signal processing array. The sound localization capabilities of a straight cochlea and a spiral cochlea are compared by examining the simulated acoustic images. The results demonstrate that the spiral shape can achieve better vertical sound localization. The analysis therefore indicates that the cochlear spiral shape might not only have evolved for space conservation reasons but also for possible perceptual benefits.