inter-list equivalency and reliability of the persian randomized dichotic digits test

background and aim: dichotic listening evaluation is one of the most common behavioral procedures for assessing the cerebral dominance of language and is considered as the main component of the auditory processing test battery in children and adults. the randomized dichotic digits test (rddt) has two lists of randomly distributed one-, two-, and three-digit items. this research was performed for studying the inter-list equivalency and test-retest reliability of persian rddt. methods: persian rddt was administered at 50 dbhl on 62 right-handed individuals (equal sex ratio) with normal hearing sensitivity in the age range of 12-45 years. the interval between the test sessions was 30 days and each session had two test rounds with an interval of 20 minutes. in each session, list 1 of the persian rddt was performed for the first round and list 2 performed for the second round. results: results demonstrated that mean right and left ear score and ear advantage of persian rddt list 1 and list 2 had no statistically significant difference (right ear p=0.25, left ear p=0.56, ear advantage: p=0.6). intra-class correlation coefficient of scores in the first and the third test rounds (list 1) for the right and left ears were 0.71 and 0.68, and for the second and the fourth test rounds (list 2) were 0.69 and 0.80, respectively. conclusion: based on the results of this study, it would seem that the two lists of persian rddt are equivalent and the mean scores have good to excellent test-retest reliability.