Microsecond-precision sound localization emerges from slow equilibrium dynamics

Abstract

Precise sound localization relies on microsecond sensitivity to interaural time differences (ITDs), yet binaural perception exhibits sluggish tracking of dynamic acoustic cues. How such extraordinary temporal precision arises despite comparatively slow neural responses remains unresolved. This study proposes that ITD is represented as a stable equilibrium of neural population dynamics rather than by the classical place-coding mechanism based on delay-line coincidence detection. In this framework, excitatory and inhibitory interactions across frequency channels drive the system toward an equilibrium corresponding to the estimated ITD. The resulting dynamics achieve microsecond-level precision and reproduce key physiological observations, including frequency-dependent best-delay distributions, without requiring explicit delay lines or precisely timed inhibition. These results challenge the classical place-coding framework and suggest a fundamentally different principle for binaural computation. More generally, the findings suggest that microsecond-level sensitivity and sluggish binaural perception may be complementary consequences of the same equilibrium dynamics, providing a potential framework for reconciling these seemingly disparate phenomena.