Objective: Hearing Impairment during childhood affects all aspects of speech production and comprehension. It seems that hearing impaired people suffer from language and speech impairments such as comprehension of structures derived by syntactic movement. The purpose of this study is to compare the comprehension of structures derived by syntactic movement in children with hearing impairment and normal children.

Materials & Methods: In this case-control research, twenty normal children, aged 6-7 years and twenty children with severe to profound hearing impairment, aged 8-12 years were selected in a simple random sampling from normal kindergartens and schools, and exceptional schools for hearing impaired people. The children didn’t have any confirmed diseases or neurological disorders, except hearing loss in students with hearing impairment. The children's aural records and also the confirmation of the audiologist in the exceptional schools for hearing impaired people were considered in order to determine the kind and degree of hearing loss. The comprehension of sentences was tested by using a researcher-made task called sentence-picture matching task. At first the content validity was determined and then the reliability was confirmed with Cronbach Alpha Test. Data were analyzed by statistical test such as Independent Samples T-Test and Mann-Whitney U Test and using SPSS software.

Results: Comprehension of the hearing-impaired group was significantly different from that of the hearing control group (P<0/05). The children with hearing impairment failed to understand structures derived by syntactic movement. Comprehension of the hearing –impaired group on structures with canonical word order was better than on structures derived by syntactic movement.

Conclusion: Incorrect answers of the children with hearing impairment to the sentence - picture matching task alludes to the incomplete comprehension of structures derived by syntactic movement.