Objective: The aim of this study was comparing ABR in normal and down children.

Materials & Methods: This study was performed between 1388 to 1391 at Akhavan rehabilitation center of University of Social Welfare and Rehabilitation Sciences Tehran and Babol Amir Kola hospital. Forty five 3-6 year-old boy with Down’s syndrome and forty five normal children were selected from available population. After case history, otoscopy and basic hearing tests, ABR test was performed. In ABR absolute latencies, interpeak latencies and amplitude ratio of V/I were analyzed. For analyzing data, parametric independent t test was selected.

Results: Latencies and inter-peak latencies of I-III, I-V (P-value<0.001), III-V (P-value=0.01) and V/I amplitude ratio (P-value<0.001) were shorter than normal. Children with Down syndrome had significantly higher threshold than normal children (P-value<0.001).

Conclusion: Peripheral auditory system development is delayed and brainstem function in children with Down’s syndrome is abnormal. Early diagnosis of hearing impairments and intervention in these children is very important because it affects communication skills.