Perceptual consequences of "hidden" hearing loss.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing animal models and preliminary observational human studies
PubMed 25204468 · doi:10.1177/2331216514550621
What was done
This narrative review synthesized findings from animal experiments and preliminary human temporal bone, electrophysiological (auditory brainstem response Wave I), and psychoacoustic studies to evaluate the causes (noise exposure, aging) and functional implications of cochlear neuropathy ('hidden hearing loss') in individuals with normal standard audiograms.
What was found
The abstract reports no quantitative values or statistical metrics. It notes that animal models demonstrate selective loss of high-threshold auditory nerve fibers without permanent threshold shifts. In humans, noise exposure history correlates with deficits in speech discrimination and temporal processing, and tinnitus is associated with reduced auditory brainstem response Wave I amplitude, though no direct link had yet connected noise exposure, cochlear neuropathy, and perceptual difficulties.
Why it matters
The paper outlines how substantial neural damage can exist behind normal pure-tone audiometry, providing a mechanistic framework for understanding unexplained hearing difficulties in noisy environments.
Limits
As a narrative review, it introduces no new primary data and lacks systematic review methodology. The abstract provides no quantitative sample sizes or effect estimates. Direct causal evidence linking cochlear neuropathy to perceptual deficits in humans was lacking at the time of publication.
Cited by
- supports Individuals with hidden hearing loss show normal thresholds on standard audiograms but report difficulty hearing in noisy environments or new-onset tinnitus.