The importance of working memory capacity for improving speech in noise comprehension in children with hearing aid

One of the most common complaints of hearing aid users is difficulty in receiving speech in noise which is very important for all hearing impaired specially children with limited auditory and language experiences. Since working memory plays a significant role in speech perception, especially in challenging auditory situations such as background noise, it is likely that differences in its performance and capacity may impair the ability to understand speech in noise in hearing aid users. Therefore, we aimed to compare memory capacity between two groups of children using hearing aids in both ears, who differed only in the ability to understand speech in noise.

In this cross-sectional study, 31 children with moderate to severe hearing impairment and the same medical and demographical conditions that using bilateral hearing aids, were examined. These students were divided into two groups according to the scores obtained in speech comprehension as follows: group one (high performance) included students whose SNR loss score in BKB-Speech In Noise test was equal or less than 7, and group two (low performance) included students whose SNR loss score was more than 7. Then, the scores of auditory working memory tests were examined in these two groups.

The scores of two working memory tests of forward and backward digit span between the two groups no differed significantly based on statistical findings (P = 0.06). But The score of working memory test of non-word repetition differed significantly between the two groups (P = 0.03) A significant correlation was found between the scores of speech comprehension in noise test and working memory tests, including forward (P = 0.004) and backward digit (P = 0.002) span tests and non-word repetition test (P = 0.000) in all subjects.

The significant correlation founded between speech perception in noise scores and working memory span, indicating the importance of working memory capacity in the ability to understand speech in noise in children with hearing aids.