The effects of noise and poor voice quality on spoken language processing in school-aged children: A systematic review
At school, children often face challenging listening conditions due to high noise levels or because they are exposed to dysphonic speakers. To date, no comprehensive review has evaluated how this might affect spoken language processing (SLP). Our aim was to systematically review the literature on the effects of noise and/or impaired voice quality on regular school-aged children's SLP. Eligibility was restricted to studies that assessed 6-18 year-old children’s performance and response times in listening tasks presented in noise and/or an impaired voice quality. We searched Medline/Ovid, PsycINFO/Ovid, Eric/Ovid, and Scopus up to August 2018. Risk of bias was determined using an adapted version of the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. We classified and discussed findings in the light of three SLP components: speech perception, listening comprehension, and auditory working memory. We identified 24 eligible studies on the effect of noise (n=14), impaired voice (n=8), and the combination of noise and impaired voice (n=2). Sixteen of these studies were evaluated to be of good quality, eight of fair quality. For each SLP component, there was evidence for the disruptive effect of either noise or impaired voice on task performance or response times. However, there was no indication of an interaction between noise and impaired voice. Results from our systematic review suggest that acoustic degradations may impede children’s speech perception, comprehension of spoken language, and ability to retain speech-encoded information. This has important implications for the educational setting and highlights the need for improved listening conditions in learning spaces.