Noise can damage high-threshold auditory fibers while audiograms still look normal

Evidence

Recent studies in animals have suggested that the low-SR/high-threshold auditory nerve fibers and their associated synaptic connections may be more easily damaged than the high SR/low threshold auditory nerve fibers when exposed to high levels of sound (Kujawa & Liberman, 2009). Auditory threshold testing may not reveal damage to the high-threshold fibers, due to the low stimulus levels associated with threshold. Consequently, it seems possible that supra-threshold tests would be necessary to identify loss of or damage to the high-threshold fibers. Scientists have speculated that loss of these fibers might contribute to speech perception difficulties in noise, even in the absence of elevated auditory thresholds. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 258

Categorization

• XREF: Ties to ‘hidden hearing loss’ literature — a normal audiogram with real supra-threshold deficits.
• SEED: Strong article angle: standard hearing tests miss damage that still causes real-world speech-in-noise difficulty.
• QUESTION: Worth chasing: what are practical supra-threshold tests clinicians could actually use?