Can working-memory training help older adults understand speech in noisy surroundings?

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Understanding speech against background sound can be challenging for older adults. Speech comprehension in noise appears to depend on working memory and executive-control processes, raising the possibility that training these abilities could have rehabilitative potential for age-related hearing loss.

Researchers examined adaptive working-memory training using Cogmed in 24 older adults. A cognitive test battery, including the Reading Span test, which is sensitive to working memory, assessed whether gains generalized to other working-memory tasks (near-transfer) or other cognitive domains (far-transfer). They also assessed far-transfer to speech-in-noise performance, including a closed-set sentence task. To examine whether cognitive training affected the benefit obtained from meaning-based context, they also tested transfer to open-set sentences: half were semantically coherent (high-context), and half were semantically anomalous (low-context).

In a crossover design over 10 weeks, participants completed both adaptive working-memory training and placebo training, with 25 sessions of each, lasting 0.5–1 hour per session at 5 sessions per week. Scores on the adaptive working-memory training tasks improved as a result of training. However, the gains did not transfer to other working-memory tasks or tasks involving other cognitive domains. No training-related improvement in speech-in-noise performance was observed.

Working-memory measures correlated with the intelligibility of low-context sentences, but not high-context sentences, suggesting that sentence context may reduce the load on working memory. The Reading Span test significantly correlated only with a test of visual episodic memory, suggesting that it is not a pure test of working memory, as is commonly assumed.