Active versus passive cleft-type speech characteristics.

Cleft palate speech is generally described in terms of nasal resonance, nasal emission and compensatory articulations. A longitudinal study of children at different stages of surgical treatment revealed a distinction between passive and active cleft-type speech characteristics whereby passive characteristics were thought to be the product of structural abnormality or dysfunction and active characteristics were specific articulatory gestures replacing intended consonants. Passive and active patterns of articulation are described and defined in the context of three longitudinal studies of subjects who were at various stages of two different surgical regimes: five bilateral cleft lip and palate (BCLP) subjects aged 1;6-4;6, 12 mixed unilateral cleft lip and palate (UCLP) and BCLP subjects aged 4;6-7;6 and nine mixed UCLP and BCLP subjects aged 9;0-11;0. Reference is also made to data from 12 mixed cleft-type subjects aged 13;0 who had been treated with different surgical timing regimes. Comparison is made between the incidence of active versus passive processes in relation to oral structure. At age 4;6 speech samples taken from BCLP subjects who had been treated with 1-stage versus 2-stage palate repair all evidenced both active and passive processes. The lack of differentiation in speech results irrespective of their current surgical status, i.e. completely repaired palates versus residual cleft of the hard palate, was unexpected. Cleft-type processes in completely repaired subjects might be accounted for by the inevitable anterior defect following repair of a bilateral cleft. Older subjects with structural defects also evidenced more cleft-type processes. The relevance of distinguishing between active and passive processes is underlined by consideration of the effects of structural changes following surgery. The effect of surgery on seven subjects' speech is discussed using the active/passive distinction. Active cleft-type characteristics did not change as a direct result of surgery, whereas passive characteristics were largely eliminated following surgery. A specific distinction is made between active and passive nasal fricatives, with the implication that active nasal fricatives may not be affected by surgical intervention, whereas passive nasal fricatives may be eliminated by surgery. Accurate distinction between active and passive patterns of articulation may serve to identify those cleft-type speech error patterns most likely to respond to surgical intervention. Indications from this study are that active cleft-type characteristics require destabilization in a course of speech and language therapy before the potential benefits of surgery can be properly assessed. An analytical protocol for the interpretation of speech samples is presented and some therapy strategies are proposed for active and passive processes.