Is speech enough? Language development evaluation in the first 6 years of prelingually deaf children. A systematic review

PURPOSE: To synthesize the relevant scientific information regarding the assessment of language development in prelingually deaf children during their first six years of life, in order to determine whether it is sufficient to confirm the presence of some language development in this population, or if a more integrated approach would be more appropriate. RESEARCH STRATEGIES: A structured review of the relevant scientific literature was carried out in the following databases: PubMed, Lilacs, Ibecs, Trip DataBase, Cochrane library, Clinical Trial and Nice. SELECTION CRITERIA: Systematic reviews, health technology assessments, randomized clinical trials, observational cohorts and case-control studies; including publications of assessments concerning any aspect of language development or any intervention in any language. Evaluations related exclusively to hearing and speech, to central, sudden or transient deafness, to deaf-blindness, to further disabilities or to autism spectrum disorders, were excluded. DATA ANALYSIS: GRADE methodology was used to analyze evidence quality. RESULTS: It is possible to evaluate the language development of prelingually deaf children. A moderate quality of evidence was obtained, suggesting that the evaluations’ results are fairly trustworthy, provided that the assessments are conducted within an integrated approach of other linguistic elements. CONCLUSION: The results of the language evaluations must be supported mostly by receptive and expressive language data, and the found evidence can be improved by combining the assessments of the formal linguistic elements of both oral and gestural modalities with the pragmatic components of the communication process.