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Background and Aim: Assessment of central auditory processing skills needs various behavioral tests in format of a test battery. There is a few Persian speech tests for documenting central auditory processing disorders. The purpose of this study was developing a dichotic test formed of one-syllabic words suitable for evaluation of central auditory processing in Persian language children and reporting its preliminary results in a group of normal children.
Materials and Methods: Persian words in competing manner test was developed utilizing most frequent monosyllabic words in children storybooks reported in the previous researches. The test was performed at MCL on forty-five normal children (39 right-handed and 6 left-handed) aged 5-11 years. The children did not show any obvious problem in hearing, speech, language and learning. Free (n=28) and directed listening (n=17) tasks were investigated.
Results: The results show that in directed listening task, there is significant advantage for performance of pre-cued ear relative to opposite side. Right ear advantage is evident in free recall condition. Average performance of the children in directed recall is significantly better than free recall. Average row score of the test increases with the children age.
Conclusion: Persian words in competing manner test as a dichotic test, can show major characteristics of dichotic listening and effect of maturation of central auditory system on it in normal children.

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Background and Aim: Learning disability is a term referes to a group of disorders manifesting listening, reading, writing, or mathematical problems. These children mostly have attention difficulties in classroom that leads to many learning problems. In this study we aimed to compare the auditory attention of 7 to 9 year old children with learning disability to non- learning disability age matched normal group.
Methods: Twenty seven male 7 to 9 year old students with learning disability and 27 age and sex matched normal conrols were selected with unprobable simple sampling. 27 In order to evaluate auditory selective and divided attention, Farsi versions of speech in noise and dichotic digit test were used respectively.
Results: Comparison of mean scores of Farsi versions of speech in noise in both ears of 7 and 8 year-old students in two groups indicated no significant difference (p>0.05) Mean scores of 9 year old controls was significant more than those of the cases only in the right ear (p=0.033). However, no significant difference was observed between mean scores of dichotic digit test assessing the right ear of 9 year-old learning disability and non learning disability students (p>0.05). Moreover, mean scores of 7 and 8 year- old students with learning disability was less than those of their normal peers in the left ear (p>0.05).
Conclusion: Selective auditory attention is not affected in the optimal signal to noise ratio, while divided attention seems to be affected by maturity delay of auditory system or central auditory system disorders.

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Background and Aim: The dichotic auditory-verbal memory test (DAVMT) is useful in detecting auditory-verbal memory deficits and differences in memory function between the brain hemispheres. The purpose of this study was to prepare the Persian version of dichotic auditory-verbal memory test and to obtain its results in 18- to 25-year old normal individuals of both genders in Iran.
Methods: The Persian version of dichotic auditory-verbal memory test like the original one consisted of 18 lists of ten words. The lists were arranged such that 10 words were presented to one ear, with the reverse words simultaneously were presented to the other ear, constituting a dichotic test situation. After preparing the 18 lists, content validity was assessed by a panel of eight experts and then, the words of each list were recorded on CD in a dichotic mode. Thereafter, it was performed on one hundred and ten normal individuals with ages ranging from 18 to 25 years (mean age: 21.3 SD 1.9 years) and the scores were recorded on a specially designed scoring sheet.
Results: There was no significant difference between mean scores of 18 lists of the dichotic auditory-verbal memory test. The overall mean of CVI was 96% for the 18 lists and the mean score of dichotic auditory-verbal memory test was 6.5 SD 1.0 in the normal group.
Conclusion: Based on the obtained results, the Persian version of dichotic auditory-verbal memory test has a good content validity and can be used in detecting the auditory-verbal memory deficits.

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Background and Aim: Bilingualism, as one of the discussing issues of psychology and linguistics, can influence the speech processing. Of several tests for assessing auditory processing, dichotic digit test has been designed to study divided auditory attention. Our study was performed to compare the auditory attention between Iranian bilingual and monolingual young adults.

Methods: This cross-sectional study was conducted on 60 students including 30 Turkish-Persian bilinguals and 30 Persian monolinguals aged between 18 to 30 years in both genders. Dichotic digit test was performed on young individuals with normal peripheral hearing and right hand preference.

Results: No significant correlation was found between the results of dichotic digit test of monolinguals and bilinguals (p=0.195), and also between the results of right and left ears in monolingual (p=0.460) and bilingual (p=0.054) groups. The mean score of women was significantly more than men (p=0.031).

Conclusion: There was no significant difference between bilinguals and monolinguals in divided auditory attention and it seems that acquisition of second language in lower ages has no noticeable effect on this type of auditory attention.

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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.

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Background and Aim: Staggered spondaic words (SSW) test examines central auditory nervous system . Some researches show stuttering causes hyperactivity in motor system of the right hemisphere and cerebellum and decreases activity in the left hemisphere. During stuttering also, central auditory processing is decreased . The aim of this study was to compare the Persian staggered spondaic word test results between persistent developmental stutterers and normal subjects.

Methods: Thirty people with persistent developmental stuttering were participants of this cross-sectional descriptive-analytic study, which were aged 11 to 40 years. The control group matched for gender and number with stutters. They were 8 females and 22 males, with the age of 11 to 40 years, without any stuttering history, neurological diseases and auditory disorders.

Results: Stutterers were in normal category in corrected staggered spondaic words test. The mean scores of errors of right compete, right ear, left compete, left ear and total in corrected s taggered spondaic words between control and stuttering group showed significant differences. There was a significant relationship between stuttering and effect, too (p<0.05).

Conclusion: Based on the obtained results of this study, stutterers may have different cortical and sub - cortical brain activity than people who have not stutter . Central auditory processing abilities of stutterers are weaker than normal people.

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Background and Aim: Cerebrovascular accident is a neurological disorder involves central nervous system. Studies have shown that it affects the outputs of behavioral auditory tests such as dichotic auditory verbal memory test. The purpose of this study was to compare this memory test results between patients with cerebrovascular accident and normal subjects.

Methods: This cross-sectional study was conducted on 20 patients with cerebrovascular accident aged 50-70 years and 20 controls matched for age and gender in Emam Khomeini Hospital, Tehran, Iran. Dichotic auditory verbal memory test was performed on each subject.

Results: The mean score in the two groups was significantly different (p<0.0001). The results indicated that the right-ear score was significantly greater than the left-ear score in normal subjects (p<0.0001) and in patients with right hemisphere lesion (p<0.0001). The right-ear and left-ear scores were not significantly different in patients with left hemisphere lesion (p=0.0860).

Conclusion: Among other methods, Dichotic auditory verbal memory test is a beneficial test in assessing the central auditory nervous system of patients with cerebrovascular accident. It seems that it is sensitive to the damages occur following temporal lobe strokes.

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Background and Aim: Memory is one of the aspects of cognitive function which is widely affected among aged people. Since aging has different effects on different memorial systems and little studies have investigated auditory-verbal memory function in older adults using dichotic listening techniques, the purpose of this study was to evaluate the auditory-verbal memory function among old people using Persian version of dichotic auditory-verbal memory test. Methods: The Persian version of dichotic auditory-verbal memory test was administered to 23 old people ranging 60-80 years and 30 young people aging 20-30 years, with normal and symmetric hearing in both ears. The performance of the two groups was compared. Results: The mean score of young (6.36±0.43) and old (4.58±0.74) adults on dichotic auditory-verbal memory test were significantly difference (p=0.001). The correlation test showed a negative correlation between age and the memory scores in aged people (r=0.36). A significant difference in recall of early (p=0.034), middle (p=0.037), and final (p=0.041) words was seen between aged and young people. Conclusion: Based on the obtained results, significant reduction in auditory memory was seen in aged group and the Persian version of dichotic auditory-verbal memory test, like many other auditory verbal memory tests, showed the aging effects on auditory verbal memory performance.

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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.

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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.