Cleft palate speech is generally described in terms of nasal resonance, nas
al emission and compensatory articulations. A longitudinal study of childre
n at different stages of surgical treatment revealed a distinction between
passive and active cleft-type speech characteristics whereby passive charac
teristics were thought to be the product of structural abnormality or dysfu
nction and active characteristics were specific articulatory gestures repla
cing intended consonants. Passive and active patterns of articulation are d
escribed and defined in the context of three longitudinal studies of subjec
ts who were at various stages of two different surgical regimes: five bilat
eral 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 1
2 mixed cleft-type subjects aged 13;0 who had been treated with different s
urgical timing regimes. Comparison is made between the incidence of active
Versus passive processes in relation to oral structure. At age 4;6 speech s
amples taken from BCLP subjects who had been treated with 1-stage versus 2-
stage palate repair all evidenced both active and passive processes. The la
ck of differentiation in speech results irrespective of their current surgi
cal status, i.e. completely repaired palates versus residual cleft of the h
ard palate, was unexpected. Cleft-type processes in completely repaired sub
jects might be accounted for by the inevitable anterior defect following re
pair of a bilateral cleft. Older subjects with structural defects also evid
enced more cleft-type processes. The relevance of distinguishing between ac
tive and passive processes is underlined by consideration of the effects of
structural changes following surgery. The effect of surgery on seven subje
cts' 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 speci
fic distinction is made between active and passive nasal fricatives, with t
he implication that active nasal fricatives may not be affected by surgical
intervention, whereas passive nasal fricatives may be eliminated by surger
y. Accurate distinction between active and passive patterns of articulation
may serve to identify those cleft-type speech error patterns most likely t
o respond to surgical intervention Indications from this study are that act
ive cleft-type characteristics require destabilization in a course of speec
h and language therapy before the potential benefits of surgery can be prop
erly assessed. An analytical protocol for the interpretation of speech samp
les is presented and some therapy strategies are proposed for active and pa
ssive processes.