Hearing distance: A low-cost model for near-field binaural effects

An extremely low-order filter model for source distance rendering in binaural reproduction is proposed in this paper. The main purpose of such model is to cheaply simulate the effect that source-listener distance has on the sound waves arriving at the ears in the near field, a region where the relation between sound pressure and distance is both highly frequency-dependent and nonlinear. The reference for the model is based on an analytical description of a spherical head response, appropriately filtered out so as to include distance-dependent patterns only. To this regard, the model is objectively seen to provide an excellent fit in the whole near field, despite its simplicity.