Longitudinal Changes in Auditory and Cognitive Function in Middle-Aged and Older Adults.
Larry E Humes
PMID 33400551WHAT IT FOUND
Over nine years, hearing thresholds and some cognitive scores declined, but dichotic temporal-order performance linked to cognitive decline more strongly than simple hearing loss.
Auditory processing speed may be a better predictor of cognitive change than pure-tone thresholds.
Key findings
01Declines in dichotic temporal-order identification were more strongly associated with cognitive decline over nine years than declines in pure-tone hearing thresholds.
02Baseline auditory temporal-order processing predicted cognitive function nine years later, whereas baseline hearing loss only predicted working memory.
03Auditory measures typically accounted for only 10% to 12% of the variance in cognitive decline or function, indicating a small but significant association.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample size of 98 may have been too small to detect subtle partial effects of hearing loss on cognitive function. Attrition bias is possible, as 105 of the original 203 prospects did not return or complete the study, although the returnees were statistically similar to non-returnees at baseline. The study focused on healthy older adults free from cognitive impairment at baseline, so results may not generalize to those with existing dementia or severe hearing loss. The long interval between tests (mean 8.8 years) helps avoid practice effects but introduces variability in the exact time between measurements.
Declared interests
The research was supported by a National Institute on Aging grant. The author declared no conflicts of interest.
The easy way to misread this
Do not conclude that hearing loss causes cognitive decline. The study found associations between rates of decline, but did not establish causation. Furthermore, the variance explained by auditory measures was small (10-12%), meaning most cognitive change was not predicted by auditory function.