Normal-threshold listeners can show temporal coding deficits localized to the auditory brainstem

Evidence

Whereas cochlear gain loss affects the whole dynamic range of sound intensities, cochlear neuropathy is thought to affect sound encoding at supra-threshold levels as high-threshold AN fibers are most sensitive to noise exposure (Furman et al. 2013 ). Indeed, a recent study has demonstrated that listeners with normal hearing thresholds can show supra-threshold hearing deficits (e.g., in envelope ITD, AM detection threshold tasks) that are related to temporal coding fidelity in the auditory brainstem while being uncorrelated to audiometric or distortion-product (DPOAE) thresholds (Bharadwaj et al. 2015 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 5872

Categorization

• XREF: Connects to hidden hearing loss / cochlear synaptopathy literature — Kujawa and Liberman’s work on temporary noise-induced AN degeneration
• QUESTION: Worth chasing: what are the clinical implications of a hearing deficit that normal audiograms miss entirely?