EPG treatment of sibilants in two Cantonese‐speaking children with cleft palate
Authors: STOKES STEPHANIE , WHITEHILL TARA , YUEN KEVIN , TSUI ANITA 
Published: April 2011

ABSTRACT  Children with disordered speech patterns have particular difficulties with fricatives and affricates, and it is also well documented that these segments are vulnerable in children with cleft palate (Grunwell, Sell & Harding, 1993). This is the case for both English‐speaking and Cantonese‐speaking children. The sibilant system in Cantonese differs from English in several ways: there are no voiced cognates, the affricates are alveolar, and there are only five sibilant segments in the system (/f/, /s/ /ts/ /tsh/ and /h/). We hypothesised that teaching the fricative (grooving) feature first, using electropalatography (EPG), would result in phonetic mastery of the affricate, since all of the features of the affricate would then be available to the child (alveolar/alveopalatal place, stopping plus grooving). The purpose of the study was to explore the efficacy of EPG as a treatment tool, to examine the rate and route of sibilant learning, and to examine the nature of affricates.

The subjects were two Cantonese‐speaking children with repaired cleft palate, aged 5;8 and 7;8. Hearing was normal. The speech and language assessment included an oral motor examination, a story retell, an articulation test, and the Cantonese Electropalatography Protocol. The subjects were fitted with acrylic palates embedded with 62 silver electrodes, and habituated to them in situ until they were comfortable, prior to data collection. The assessment was audio‐ and video‐recorded and was completed within 1 1/2 hours.

Perceptual analysis of whole‐word transcriptions were completed to construct the phonetic and phonemic inventories for each child. Electropalatographic data were analysed for the critical feature of frication (location and width of grooving) and those for affricates (place and amount of maximum constriction for the plosive, and features of grooving at the moment of release on to the fricative).

Therapy included a combination of traditional and instrumental techniques. The children attended eight treatment sessions, each of 60 minutes' duration.

Some cross‐linguistic differences were noted: these children maintained the feature of frication by bilabial fricatives. Both children made rapid progress from /s/ in isolation to /s/ in story retell and generalised the feature of frication to affricate. However, neither child achieved a normal template for [s]. The patterns for post‐treatment affricates showed that the location of the plosive component of the affricate was dependent on the location of the fricative, which was similar to the singleton [s].

The rate and route of change seen in these children's speech patterns may further our understanding of the nature of affricates, their developmental route, and the difficulty they pose for children with speech disorders. These findings were used to explore five theories: motor theory (Fletcher, 1989); a coarticulation theory (Gibbons & Hardcastle, 1994); a frequency theory (Gibbon & Hardcastle, 1994); a matrix configuration theory (Manuel, 1990), and a sensory/feedback theory (Bzoch, 1979). The feedback theory and the matrix configuration theory were supported. The findings have implications for the description and treatment of speech disorders.