Objective estimation of loudness growth in hearing-impaired listeners

A methodology for the estimation of individual loudness growth functions using tone-burst otoacoustic emissions (TBOAEs) and tone-burst auditory brainstem responses (TBABRs) was proposed by Silva and Epstein [J. Acoust. Soc. Am. 127, 3629-3642 (2010)]. This work attempted to investigate the application of such technique to the more challenging cases of hearing-impaired listeners. The specific aims of this study were to (1) verify the accuracy of this technique with eight hearing-impaired listeners for 1- and 4-kHz tone-burst stimuli, (2) investigate the effect of residual noise levels from the TBABRs on the quality of the loudness growth estimation, and (3) provide a public dataset of physiological and psychoacoustical responses to a wide range of stimuli intensity. The results show that some of the physiological loudness growth estimates were within the mean-square-error range for standard psychoacoustical procedures, with closer agreement at 1 kHz. The median residual noise in the TBABRs was found to be related to the performance of the estimation, with some listeners showing strong improvements in the estimated loudness growth function when controlling for noise levels. This suggests that future studies using evoked potentials to estimate loudness growth should control for the estimated averaged residual noise levels of the TBABRs.