<p dir="ltr">Sensorineural hearing loss (SNHL) resulting from cochlear damage has been shown to elevate hearing thresholds (reduces audibility), broaden auditory filters (reduces frequency selectivity which in turn reduces word recognition ability-particularly in adverse listening conditions), and produce abnormal growth of loudness. The use of hearing aids with prescribed amplification has been shown to improve both audibility and word recognition ability in most SNHL individuals, but not all. The neural bases for these perceptual deficits are not well understood. The few published reports evaluating auditory nerve single unit responses; and ensemble brainstem phase-locked neural activity appear to suggest that these perceptual deficits may be due, at least in part, to altered and/or degraded neural representation of certain acoustic features preserved in the temporal fine structure (TFS), and/or the envelope periodicity (ENV) of complex sounds like speech. In an effort to address this knowledge gap, we propose to evaluate the consequences of SNHL on the neural representation of the ENV and TFS of consonant-vowel syllables (CV) as reflected in the scalp-recorded brainstem envelope following response (FFR_ENV) and the fine structure following response (FFR_TFS), respectively. The concurrent recording of these brainstem responses (FFR_ENV and FFR_TFS) and the cortical acoustic change complex (ACC) will allow us to compare the nature of neural representation at two processing levels (auditory cortex and rostral brainstem) along the auditory neuraxis. Comparison of: (i) neural responses elicited by unprocessed and optimal hearing-aid processed stimuli will enable us to determine if prescribed hearing-aid processing will improve the neural representation of acoustic features important for speech perception. Such an outcome can potentially suggest the use of these neural metrics as an objective clinical tool to provide hearing aid outcome measures, which in turn could be used to tailor optimal signal processing in hearing aids to improve benefits at the individual level; and (ii) since one major complaint of hearing impaired listeners is increased difficulty in adverse listening conditions it would be interesting to evaluate if individuals with SNHL with degraded neural representation is relatively more susceptible to greater degradation in adverse listening conditions. Finally, measures of neural representation with and without visual cues will enable us to evaluate the influence of visual cues on the neural representation of the acoustic features of complex sounds in normal and impaired ears.</p>