Speech in Noise: Implications of Age, Hearing Loss, and Cognition

Introduction: Individuals with hearing loss have reduced hearing sensitivity and may not adequately process the temporal cues in acoustic signals. Cognitive skills that decrease with aging and hearing loss contribute negatively on the ability to understand speech. Hence, they may experience communication problems in noisy environments. The aim of the study was to investigate the effect of sloping high-frequency hearing loss on speech perception in noise and to examine the impact of temporal and cognitive processing in young and middle-age adults.

Methods: Speech in noise (SIN), temporal processing, and cognitive tests were conducted to hearing loss and normal hearing individuals aged 18-59 years. The measurements included the matrix sentence test, binaural temporal fine structure sensitivity (TFS) test, Visual Aural Digit Span (VADS), and Auditory Verbal Learning Test (AVLT). Twenty participants with normal hearing were recruited in the control group, whereas 20 participants with hearing loss at high frequencies were composed of the study group.

Results: Hierarchical regression analysis for SIN was performed by entering 3 separate blocks of independent variables. We entered age and hearing loss into the first block, which explained a significant amount of variability in SIN (R2 = 0.72, p < 0.001). Block 2 was comprised of scores from TFS sensitivity test, and this independent variable characterized temporal processing (R2 change = 0.002, p < 0.001). Block 3 was consisted of scores from VADS test and AVLT; these variables characterized cognitive processing and accounted for a good portion of SIN variance (R2 change = 0.04, p < 0.001). The age, hearing loss, and VADS contributed independently in the presence of all independent variables.

Conclusion: The final model accounted for 76.2% of the variance in SIN. The results suggested that sloping hearing loss, aging, and cognitive decline affected auditory performance, and the poor performance starts from an early age. Additionally, the findings indicated that a more comprehensive approach might be recommended to evaluate the listening skills and identify communication problems.