Speech and Language Consequences of Unilateral Hearing Loss: A Systematic Review.

Objective Unilateral hearing loss has been shown to have negative consequences for speech and language development in children. The objective of this study was to systematically review the current literature to quantify the impact of unilateral hearing loss on children, with the use of objective measures of speech and language. Data Sources PubMed, EMBASE, Medline, CINAHL, and Cochrane Library were searched from inception to March 2015. Manual searches of references were also completed. Review Methods All studies that described speech and language outcomes for children with unilateral hearing loss were included. Outcome measures included results from any test of speech and language that evaluated or had age-standardized norms. Due to heterogeneity of the data, quantitative analysis could not be completed. Qualitative analysis was performed on the included studies. Two independent evaluators reviewed each abstract and article. Results A total of 429 studies were identified; 13 met inclusion criteria and were reviewed. Overall, 7 studies showed poorer scores on various speech and language tests, with effects more pronounced for children with severe to profound hearing loss. Four studies did not demonstrate any difference in testing results between patients with unilateral hearing loss and those with normal hearing. Two studies that evaluated effects on speech and language longitudinally showed initial speech problems, with improvement in scores over time. Conclusions There are inconsistent data regarding effects of unilateral hearing loss on speech and language outcomes for children. The majority of recent studies suggest poorer speech and language testing results, especially for patients with severe to profound unilateral hearing loss.