Characteristics of cleft palate speech.

In recent years, interest in the nature of cleft palate speech and the influences on speech quality has increased. This overview of contemporary research reveals new perspectives on cleft palate speech development and the phonological consequences of early articulatory constraints. Cleft palate speech is perceived as the result of the synthesis between physical, physiological, cognitive and linguistic development. Developmental influences on cleft palate speech are considered in the context of early vocalisations of cleft and non-cleft children, followed by an examination of the literature on the development of babble, the emergence of early words and consonant development in children born with cleft palate. Speech development is then discussed from a phonological perspective interpreting reported characteristics as 'cleft-type developmental processes', for example, lack of target stabilisation; compensatory articulations; active/passive strategies; and systematic sound preference. Given these influences on speech development the extent to which cleft palate speech should be regarded as an 'articulatory disorder' has been reconsidered. Descriptions and interpretations of nasal resonance, nasal emission, and nasal turbulence are followed by discussion of articulatory errors in place and manner and patterns of change in cleft palate speech. Finally, some of the available evidence on speech in relation to structural imperfections, such as unrepaired clefts, velopharyngeal insufficiency, oro-nasal fistulae, dental and occlusal deviations, and open-mouth posture is summarised briefly. These new perspectives aim to facilitate more effective clinical management and to provide indications for future research.