Age-related hearing decline begins even with clinically normal pure-tone audiograms

Evidence

Conclusions The results show that even in a group of people with normal hearing, increasing age was associated with reduced speech understanding, reduced TFS sensitivity, and reduced stimulus encoding accuracy (for the modulated tone stimulus). People with good TFS sensitivity also generally had less faithful brainstem encoding of a complex harmonic tone. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4155

Results Speech-in-noise performance was positively correlated with TFS sensitivity, and negatively correlated with age. TFS sensitivity was also positively correlated with stimulus encoding accuracy for the complex harmonic stimulus, while increasing age was associated with lower stimulus encoding accuracy for the modulated tone stimulus. Conclusions The results show that even in a group of people with normal hearing, increasing age was associated with reduced speech understanding, reduced TFS sensitivity, and reduced stimulus encoding accuracy (for the modulated tone stimulus). — Dijk, Pim van, Physiology, Psychoacoustics and…, 4154

Categorization

• QUESTION: The last sentence is odd - good TFS sensitivity associating with less faithful brainstem encoding seems counterintuitive unless TFS processing happens at a different level than brainstem encoding fidelity. Worth checking the original study.
• XREF: Connects to the ‘hidden hearing loss’ / cochlear synaptopathy literature described by Liberman and Kujawa.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 4155; Dijk, Pim van, Physiology, Psychoacoustics and…, 4154