Abstract

I will present some thought provoking preliminary results that shed light on a long-running debate in the hearing community. The debate can be traced back to a simple question: what information is carried in the firing rate of auditory nerve fibres and what information is carried in the precise timings of action potentials? The firing rates of auditory nerve fibres appear to encode the sub-band envelopes of sounds whereas the timing information appears to encode the carriers, or fine structure, hence the moniker the “envelope and fine-structure debate”. I will propose a new approach to understanding this debate which is to iteratively shape a signal using an optimisation procedure so that it has the same sub-band envelope properties as a target sound. This enable us to assess what perceptual information is carried in the envelopes. The preliminary results are surprising have implications for the simulation and operation of hearing devices.