Speech can be resynthesized to selectively remove cochlear compression in hearing listeners

Evidence

We have developed a computational model of HI and an HI simulator that allow us to perform behavioural experiments on cochlear compression—experiments in which young normal hearing (NH) listeners act as “patients” with isolated, sensory-neural hearing losses of varying degree. The HI simulator is essentially a high-fidelity synthesizer based on the dynamic, compressive gammachirp filter bank (dcGC-FB) (Irino and Patterson 2006 ). It analyses naturally recorded speech sounds with a model of the auditory periphery that includes fast-acting compression and then resynthesizes the sounds in a form that counteracts the compression in a NH listener. They hear speech with little distortion or background noise (Irino et al. 2013 ) but without their normal compression. This makes it possible to investigate recruitment phenomenon that are closely related to loss of cochlear compression (Bacon et al. 2004 ) using NH listeners who have no other auditory problems. Specifically, we describe an experiment designed to examine how the loss of cochlear compression affects the recognition of relatively soft syllables occurring in the presence of louder, flanking syllables of varying levels. The aim is to reveal the role of cochlear compression in multi-speaker environments or those with disruptive background noise. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4046

Categorization

• QUESTION: Worth chasing: does removing compression via dcGC-FB resynthesis preserve the temporal-fine-structure cues that real inner-hair-cell loss would also degrade? The simulator isolates compression but real presbycusis never does.
• SEED: An essay angle: prosthetics and simulators that isolate a single sensory mechanism let us run ‘controlled experiments’ on ourselves — a model for how to decompose any complex impairment.