الفهرس 
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Abstract
Autism spectrum disorder (ASD) is a heterogonous behaviourally labeled disorder that is characterized by limitations in social contact and communication skills and associated with repetitive patterns of behaviors and interests and atypical sensory processing. Sensory processing difficulties in ASD individual extend to include vision, touch, taste, proprioception and hearing These perceptual disruptions are considered an essential diagnostic finding in ASD and constitute the building blocks for higher order functions specially speech and communication in other words abnormal auditory processing is considered one of the main factors leading to language impairment in ASD There are evidences for reduced orientation to auditory information and in particular to speech in ASD, impaired processing of auditory stimuli and in particular speech in background noise, impaired processing of affective prosody, and grammatical prosody has also been observed in ASD.
Structural and functional abnormalities that contribute to the auditory processing impairments were evident in individuals with ASD, corpus callosum -a brain structure that is directly involved in interhemisheric transfer of auditory information- was found to be of a small size or even agenetic in ASD imaging and functional studies. Deficits in dichotic listening had been proved to be related to language and learning in children. While performing dichotic listening tasks, some ASD children don’t show the usual right ear advantage for speech stimuli, instead they prefer to use their left ear when listening to both speech and musical stimuli. Studies of handedness also elevated high rates of left handedness in ASD.
The human brain has the ability to change and to reorganize of in response to environmental modifications, which is known as plasticity. Auditory training has been shown to produce long-lasting functional and structural changes in the brain and modify the aberrant connections in ASD, with subsequent enhancement of auditory processing in ASD.
Unfortunately, there is limited behavioral research on measuring auditory processing skills in children with ASD and on the success or failure of auditory training, Dichotic training in particular targets interhemispheric transfer and the process of binaural integration that is impaired in children with ASD. Studies show Dichotic training had improved children diagnosed with speech and language disorders, head trauma, and also improved language processing in typically developing children.
ASD is not labeled by cognitive impairment, so we hypothize and predict to measure auditory processing skills in such children behaviorally and then target dichotic listening deficits by dichotic training and we hypothize that children with ASD may benefit from such training by reorganizing and strengthening the neural substrates involved in dichotic listening with subsequent improvement of other auditory and language processing skills.
A total number of 30 children with age range from six to twelve years were included in this non randomized field experiment that had two main purposes; first to assess central auditory processing skills in ASD children by a behavioral way and the second purpose was to evaluate the effect of dichotic training in children with significant interaural asymmetry that revealed during assessments.
The results of measuring CAP skills supports previous researches in confirming the heterogeneity of ASD as some children performance was identical to typically developing peers while other children performance was borderline and on the other hand some children were substantially affected. Dichotic listening examination in ASD children shows abnormal cerebral organization in some children in the form of reversal of ear advantage that is supported by previous studies, while in other children there was abnormally large strong ear advantage denoting deficits in interhemispheric transfer. Fourteen children showed significant interaural asymmetry and by dichotic training, ten out of these fourteen children demonstrated obvious improvement in the dichotic listening task together with other advantages occurred in auditory and language processing skills that were highly correlated.
This study proved our hypothesis that there are basic auditory perceptual deficits in ASD children not due to higher order cognitive functions and these deficits could be measured in away more or less similar to testing normal individuals in subgroup of high functioning ASD children and these children can benefit from remediation in strengthening auditory pathways responsible for their deficits not only in the auditory task but also the benefits could be generalized to include other areas as well.