Assessing intelligibility in speakers with cleft palate: A critical review of the literature

Abstract

Objective: A literature review was conducted in order to investigate three research questions: How is speech intelligibility being measured in speakers with cleft lip and palate? Is intelligibility adequately being distinguished from related measures such as acceptability? Has there been an increased understanding of intelligibility deficits in speakers with cleft lip and palate? Fifty-seven relevant articles published between 1960 and 1998 were included in the analysis. Results: The results showed an increase in the number of articles that included a measure of intelligibility or a similar measure. Several concerns were raised as a result of the review, including the reliability and validity of measures being employed, adequate definition and differentiation of terms, and the need to determine speech and nonspeech variables contributing to reductions in intelligibility. Relevant literature on intelligibility from fields outside cleft lip and palate is reviewed, and a number of recommendations are made regarding the measurement of intelligibility in speakers with cleft lip and palate.