Age-related speech-in-noise difficulty stems from declining endocochlear potential, not just threshold elevation

Evidence

As people age, this task becomes increasingly difficult, and elevated thresholds alone cannot account for this increased difficulty (e.g., Pichora-Fuller et al. 1995 ). One explanation for this discrepancy may be attributed to the decrease in the endocochlear potential that tends to occur with increasing age (e.g., Schuknecht et al. 1974 ). A decreased endocochlear potential negatively affects the function of inner and outer hair cells (OHCs) (e.g., Gates et al. 2002 ), and disruptions in OHC function could decrease cochlear nonlinearity (e.g., Schmiedt et al. 1980 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 921

Categorization

• XREF: Connects to known phenomenon that audiometric thresholds underestimate real-world hearing decline in aging — ties to spatial hearing / speech-segregation research.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 921