Effect of noise on speech intelligibility and cognitive skills by ages

Abstract

ABSTRACT Research on older adults who have difficulty understanding speech initially focused on the peripheral auditory system, however, recent studies have emphasized the importance of cognitive factors. Previous studies typically examined older individuals with hearing loss, making it difficult to discern the importance of memory capacity on speech recognition and memory tests generally were performed in quiet environment. This study aimed to determine the speech intelligibility in noise, evaluate short-term and working memory capacities in a noisy environment as an innovative approach in young and old individuals with normal hearing, and examine the relationship between them. The study included 25 young (18–40 years) and 21 elderly (55–70 years) individuals with normal hearing. Turkish matrix sentence test was conducted as a speech intelligibility in noise test. Short-term memory was measured with forward digit span task; working memory was measured with backward digit span task. These tasks were performed in quiet and noisy environments. The elderly group had lower results in the forward (p < 0.01) and backward (p = 0.011) digit span tasks in a noisy environment than those in the quiet environment. Memory tasks in two listening conditions and Turkish matrix sentence test results were lower in the elderly group than the younger group (p < 0.01). There was a moderate negative correlation between Turkish matrix sentence test results and forward digit span tasks in the elderly group (p = 0.013). The results suggest that short-term and working memory capacities decline with age and that older individuals’ abilities are more affected by noise.