Objective: To study classification of the articulation errors, find the related factors which affect the therapy effect, and compare the therapy effect in the different patterns of the phonemic errors and build up a clinical model of the speech therapy on the basis of more than 4 years speech therapy in the clinic.
Method: After excluding the organic articulation disorders, 91 cases of consonant phonemic errors were classified into different patterns according to the phonemic placement errors. The 91 cases were divided into two groups as effective one and ineffective one depending on whether the symptoms disappeared or not after the speech therapy. Ten factors including sex, age, oral-motor function problem, developmental delay, history of language development delay, history of middle ear affection, lingua frenata, mental retardation, the therapy frequency and times, were analyzed. The statistics software SPSS (SPSS Inc, 1997) was applied to show the factors related to the therapy effect by logistic multiple stepwise regression analysis. The therapy effect was compared between the single pattern (phonemic error < 2 groups) and multiple pattern (phonemic errors > or = 2 groups).
Results: The 91 cases with consonant phonemic errors were classified into four groups. The multiple pattern of the articulation errors was the most common (37 cases, 41%) among the 4 groups, followed by velar errors (33 cases, 36%). The third one was the apico-dental errors (12 cases, 13%) and the last one was the linguo-alveolar errors (8 cases, 9%). Only one case had labiodental error (/f/). The logistic multiple stepwise regression analysis showed that the history of the positive developmental delay, language delay and the frequency of the speech therapy were related to the therapy effect. The effective rate of the speech therapy in the single pattern of the phonemic error was as high as 87% while the one in the multiple pattern group was only 2.7%. The difference was significant (P < 0.000 1) when the therapy effect in these two groups was compared. The clinical model of the speech therapy included speech assessment, designing of the goal, choice of the target sound, sound production and oral-motor functional training.
Conclusion: The consonant phonemic errors in the clinic represent four groups. The developmental delay, the language delay and frequency of the speech therapy influence the therapy effect. The frequency of the speech therapy should be increased every week, for example not less two times a week. The therapy effect of the single pattern of the phonemic errors is much better than that of the multiple pattern. The primary model of the speech therapy has been built in the clinics.