The Association Between Cognitive Performance and Speech-in-Noise Perception for Adult Listeners: A Systematic Literature Review and Meta-Analysis.

Most included studies did not justify sample size, so a study finding no association may not mean there is no association. The review combined studies that used different speech-in-noise tests and cognitive tests, so the pooled association may not apply to every clinical test. It could not separate hearing groups because studies included overlapping ranges from normal to mild or moderate loss. Crystallized intelligence showed no significant pooled association, and the studies gave very different results. Many cognitive domains, including alerting, orienting, and fluid intelligence, had too few studies to analyze. The review did not examine aided listening or hearing intervention, so it says little about hearing aid users. The speech-in-noise categories did not distinguish tests that changed noise level during the test from tests that kept it fixed, and they ignored response type, intelligibility level, and presentation mode. Many included studies did not report conflicts of interest, so commercial influence in the underlying evidence cannot be ruled out.

Do not read these associations as proof that cognitive ability causes difficulty with speech in noise. The included studies measured both at one time point, and many individual study results were not significant.