In joint disorder, the child chooses the right phoneme but pronounces it incorrectly, due to a deficiency of the joint mechanism. In other words, it can be caused by an abnormal structure of the joints or a misunderstanding of the articular motor pattern.
In phonological disorder the child chooses and uses the wrong phoneme due to reduced perception, processing and organization of phonemes in a word.
According to the Test of Phonetic and Phonological Evolution of the Panhellenic Association of Speech Therapists (1995)
.
AGE |
AGREEMENTS |
3;6 – 4;00 | sp pl kl vl kn pn pc nγ |
4;00 – 4;06 | fl st sk sc ps ks xt tr kr δj zm mn |
4;06 – 5;00 | sf vr dr xn zγ ft |
5;00 – 5;06 | γl γr str |
5;06 – 6;00 | δr θr xtr ftc |