Reversible threshold shifts after noise exposure mask ongoing neural degeneration
Evidence
It is sobering to consider that normal threshold sensitivity can mask ongoing and dramatic neural degeneration in noise-exposed ears, yet threshold sensitivity represents the gold standard for quantifying noise damage in humans. Federal exposure guidelines (OSHA, 1974; NIOSH, 1998) aim to protect against permanent threshold shifts, an approach that assumes that reversible threshold shifts are associated with benign levels of exposure. Moreover, lack of delayed threshold shifts after noise has been taken as evidence that delayed effects of noise do not occur. The present results contradict these fundamental assumptions by showing that reversibility of noise-induced threshold shifts masks progressive underlying neuropathology that likely has profound long-term consequences on auditory processing. The clear conclusion is that noise exposure is more dangerous than has been assumed. — , Toole, Floyd E - Sound reproduction-…, 1815 (
#corroborates, via linked claim)
Categorization
- XREF: connects to: One second of exposure triggers neural spectral adaptation in hearing — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1252; Inner-ear damage permanently corrupts higher-level auditory perception, not just thresholds — Toole, Floyd E, Sound reproduction- the acoustics and…, 1879; Recovered hearing thresholds can mask permanent neural damage — , Toole, Floyd E - Sound reproduction-…, 1815 (+8 more)
Broader Connections
- Recovered hearing thresholds can mask permanent neural damage
#corroborates(0.95) — , Toole, Floyd E - Sound reproduction-…, 1815 - Hidden hearing loss can impair speech in noise without raising thresholds
#corroborates(0.85) - Neural hearing damage occurs without measurable threshold elevation
#corroborates(0.80) - A temporary threshold shift signals elevated risk of permanent hearing loss
#expands(0.75) - Tinnitus after exposure signals damage even below the 85 dB threshold
#expands(0.72) — David Howard, Jamie Angus, coustics and Psychoacoustics, 684 - Elevated gap detection thresholds in hearing loss stem from threshold elevation, not temporal pathology
#contradicts(0.70) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 964