Decline in older persons' ability to recognize speech in noise: the influence of demographic, health-related, environmental, and cognitive factors

OBJECTIVES:: The first aim was to investigate whether the rate of decline in older persons' ability to recognize speech in noise over time differs across age and gender. The second aim was to determine extent demographic, health-related, environmental, and cognitive factors influence the change in speech-in-noise recognition over time. DESIGN:: Data covering 3 to 7 years of follow-up (mean: 4.9 years) of a large sample of the Longitudinal Aging Study Amsterdam were used (n = 1298; 3025 observations; baseline ages: 57 to 93 years). Hearing ability was measured by a digit triplet speech-in-noise test (SNT) yielding a speech reception threshold in noise (SRTn). Multilevel analyses were used to model the change in SRTn over time. First, interaction terms were used to test differences in rate of decline across subgroups. Second, for each of the following factors the authors determined the influence on the change in SRTn: age, gender, educational level, cardiovascular conditions, information processing speed, fluid intelligence, global cognitive functioning, smoking, and alcohol use. This was done by calculating the percentage change in Btime after adding the particular factor to the model. RESULTS:: On average, respondents' SRTn increased (i.e., deteriorated) significantly over time by 0.18 dB signal-to-noise ratio per annum. Rates were accelerated for older ages (Btime = 0.13, 0.14, 0.25, 0.27 for persons who were 57 to 65, 65 to 75, 75 to 85, and 85 to 93 years of age, respectively). Only information processing speed relevantly influenced the change in SRTn over time (17% decrease in Btime). CONCLUSIONS:: Decline in older persons' speech-in-noise recognition over time accelerated for older ages. Decline in information processing speed explained a moderate proportion of the SRTn decline. This indicates the relevance of declining cognitive abilities in the ability of older persons to recognize speech in noisy environments. Copyright © 2013 by Lippincott Williams & Wilkins