One way to examine a child's ability to think about language is by word definition. Word definition is a meta-linguistic skill representing the aspect of the lexical knowledge of a person about the nature and function of language. The success of a person in defining the word is indicative of the fact that he is aware of the use of language as a symbolic system and a tool for transferring information about the world around him and his own inner states, ideas, and purposes. The studies about word definition skill consider two content and form aspects within the development of vocabulary skill. ‘Content’ is the expression of the semantic features of a word that is expressed in a definition, and ‘Form’ is the syntactic structure of a definition and how it is formulated to transfer the best information which exists about a word in mind. Considering the importance of hearing sense on learning and use of language and meta-linguistic skill, the delay or problem in obtaining word definition skills in children with hearing loss is predictable, however, this question may arise that how is the quality of word definition skills in children with hearing impairment. The study aimed to compare the skill of noun definition in terms of content and form in children with Cochlear Implant (CI) and Typically Developing (TD) children.
In this descriptive-analytic study, samples included 16 students (8 girls and 8 boys) with CI in the third grade of primary school (8-9 years old) by available sampling from Tehran Cochlear Implants based on inclusion criteria including education in regular schools, 100 Cochlear Implant training sessions, resolution Intermediate Speech was selected according to the Speech and Language Pathologist's viewpoint, not having a mental disability, passing a pre-school entrance examination, and failing a passing grade in previous years. All children before the age of 3 received Cochlear Implants and had hearing aid in their other ear and, according to their parents' statements, used hearing aids as prescribed by experts after their hearing loss was identified. Thirty normal children (15 girls and 15 boys) were randomly selected based on the following criteria: no hearing, speech, and language problems (being normal), no failing score in previous years, no psychological problems, and no lack of mental disability. Exclusion criteria in this study were the child or parental unwillingness to continue the test during the study. In this study, Mohammadi’s Noun Definition Test, which was designed and validated for Persian-speakings, was used. This test evaluates the skill of word definition of students in seven categories including animals, occupations, fruits, places, body organs, foods and transport items. The validity of Name Definition Test was estimated in the content aspect (r=81%) and in the form aspect (r=91%) estimated by correlating the scores of two independent evaluators. Data were analyzed using SPSS-24 software by Shapiro-Wilk and Mann-Whitney tests. All comparisons were considered significant at α=0.05 level.
The findings indicated that the mean scores of content and form aspects of Noun Definition Test were significantly lower in children with CI than their TD peers (P<0.001). The children with CI used significantly more concrete and functional responses in the content aspect, and had significantly less transitional and Aristotelian forms in the form aspect in comparison with their TD peers (P<0.001), while hearing children used significantly more Combination I and II responses in the content aspect, and had significantly more Clause, Transitional and Partial Aristotelian forms in the form aspect.
The significance of the means obtained in comparing the content and structural aspects of noun definitions indicates that children with CI have lower performance in both content and structure of the nouns than hearing children. It seems that the content and structural growth pattern of the definition of CI in children is almost similar to that of younger hearing-children. According to the results of this research, developing a coherent program to teach the noun definition skills in cochlear implant children with CI seems necessary.