The present study was designed to compare the phonological processes between the
hearing-impaired (HI) children and the mentally retarded (MR) children. Twenty eight
children participated in this study; 14 of the hearing-impaired children (HI group) who
showed severe to profound hearing loss, 14 of the mentally retarded children who were
matched with the hearing-impaired children by their percentage of consonants correct
(PCC). t-test analyses were conducted to analyze the difference between the two groups.
Data were analyzed based on structure processes (syllable reduction, addition, and
omission), substitution processes, assimilation processes, tension/aspiration processes, and
vowel processes.
Results showed that several processes were significantly different between the two
groups: (1) syllable reductions and bilabial deletion, (2) backing of alveolars, labialization,
and velarization, (3) stop assimilation, (4) laxing, aspiation, deaspiration, and vowel
deviation. Although the phonological processes of the two groups were similar to young
children (2-3yrs), this patterns of developmental delay was more salient in MR children
than HI children. It was also noted that HI children used more aspiration than MR
children. These patterns seem to be useful in the evaluation of the hearing impaired
children and mentally retarded children.