Physiologically motivated individual loudness model for normal hearing and hearing impaired

Abstract

One consequence of sensorineural hearing loss is an altered loudness perception with a typically steeper progression of loudness as a function of stimulus level (loudness recruitment). Existing loudness models aim to explain altered loudness functions in hearing impaired (HI) effectively by means of an attenuation and compression component. Here the physiologically motivated loudness model of Pieper et al. [J. Acoust. Soc. Am. 139, 2896 (2016)] which simulates the nonlinear inner ear mechanics (transmission-line model, TLM) is used and extended to help distinguishing the role of peripheral factors, like damage to the outer hair cells (reduction of cochlear gain), and higher stages of auditory processing on loudness perception. Individual hearing thresholds were simulated by cochlear gain reduction in the TLM and linear attenuation (damage of inner hair cells) prior to an internal threshold. Hearing threshold and cochlear gain loss were estimated from individual loudness scaling data for narrowband noise. It was demonstrated that existing loudness models fail to predict individual loudness functions for HI. The current model showed better agreement with the data and accounted for individual loudness functions in HI and normal hearing using a linear weighting above the internal threshold (referred to as post gain).