Background and Aim: Dichotic listening means presentation of two different auditory stimuli to each ear simultaneously. This study deals with the development of Persian version of Bergen dichotic listening test and its preliminary results on auditory attention and language laterality in adults with normal hearing.

Methods: Persian version of the Bergen dichotic listening test was instructed by six consonant-vowel syllables to evaluate three conditions of non-forced attention, attention to right and attention to left ears separately. Then, it was performed on 54 right-handed young adults with normal hearing and the mean age of 23.24 (SD=2.78) years from both genders.

Results: Frequency of correct response in the right ear was higher significantly in two conditions of non-forced attention (83.3%) and attention to the right ear (98.1%), and also was higher significantly in the left ear (-79.6%) in attention to the left (p<0.0001). Laterality index was 31.33% in non-forced attention, 73.30% in attention to the right and -37.50% in attention to the left which was significantly different (p<0.0001).

Conclusion: Right ear advantage was revealed in non-forced attention that was altered with selective attention to the right and left remarkably result from the effect of top-down processing of brain cortex on bottom-top processing of speech stimulus. These preliminary results showed the performance of Bergen dichotic listening test to test auditory attention and language laterality.

Background and Aim: Although double dichotic digit test is a useful tool for assessing the central auditory system in adults, it is more useful for evaluating younger children. The present study aimed to develop the Persian version of the single dichotic digit test and to obtain initial normative data.

Methods: The Persian version of the present test consisted of three different sets of 25 single digit pairs for testing in the free recall, directed recall to right, and directed recall to left conditions. The digits in each list were recorded dichotically on a compact disc. The sectional study was performed on 126 male students, aged between 7 and 9. The test-retest reliability was assessed in 29 subjects two to four weeks after the first test session.

Results: In seven year olds, the mean right and left ear scores increased from around 95.79% and 89.69%, respectively. In eight year olds, the mean right and left ear scores increased from around 98.59% and 96.29%, respectively. The mean right ear advantage decreased from around 6.13% in 7 year olds to around 2% in 8 year olds (p=0.001). No significant difference was found in scores between the free recall and directed recall conditions (p>0.05). The test had a high test-retest reliability (p>0.05).

Conclusion: The Persian version of the test has a high test-retest reliability for evaluating male children aged between 7 and 9 it can be used for assessing binaural integration in male children of this age group.

Background and Aims: The dichotic listening subtest is considered as an important component of the test battery for auditory processing assessment in both children and adults. A randomized dichotic digits test (RDDT) was created to compensate for sensitivity weakness of double digits when detecting abnormal ear asymmetry during dichotic listening. The aim of this study was the development and initial evaluation of the Persian randomized dichotic digits test.

Method: Persian digits 1-10 (except for the bisyllabic digit, 4) uttered by a native Persian language speaker were recorded in a studio. After alignment of intensity and temporal characteristics of digit waveforms, lists 1 and 2 of the RDDT were reproduced. List 1 of the test was administered at 55 dBHL on 50 right-handed normal hearing individuals (with an equal sex ratio) in the age group of 18-25 years and hearing thresholds of 15 dBHL or better in audiometric frequencies.

Results: Mean (standard deviation) percent-correct score for right and left ears and right ear advantage of the subjects was 94.3 (5.3), 84.8 (7.7), and 9.5 (7.0) percent, respectively. Sixty percent of the subjects showed normal results and unilateral and bilateral deficits were seen in 24 percent and 16 percent, respectively.

Conclusion: It seems the Persian version of RDDT is the same as the original test as it is able to test ear asymmetry , unilateral and bilateral deficits in dichotic listening.