Deficit of auditory temporal processing in children with dyslexia-dysgraphia

• Main Authors: Sima Tajik, Mansoureh Adel Ghahraman, Ali Akbar Tahaie, Fahimeh Hajiabolhassan, Leila Jalilvand Karimi, Shohreh Jalaie
• Format: Article
• Language: fas
• Published: Tehran University of Medical Sciences 2012-12-01
• Series: Audiology
• Subjects: Auditory temporal processing; gap-in-noise test; dyslexia; dysgraphia; learning disability
• Online Access: http://aud.tums.ac.ir/browse.php?a_code=A-10-25-22&slc_lang=en&sid=1

Background and Aim: Auditory temporal processing reveals an important aspect of auditory performance, in which a deficit can prevent the child from speaking, language learning and reading. Temporal resolution, which is a subgroup of temporal processing, can be evaluated by gap-in-noise detection test. Regarding the relation of auditory temporal processing deficits and phonologic disorder of children with dyslexia-dysgraphia, the aim of this study was to evaluate these children with the gap-in-noise (GIN) test.Methods: The gap-in-noise test was performed on 28 normal and 24 dyslexic-dysgraphic children, at the age of 11-12 years old. Mean approximate threshold and percent of corrected answers were compared between the groups.Results: The mean approximate threshold and percent of corrected answers of the right and left ear had no significant difference between the groups (p>0.05). The mean approximate threshold of children with dyslexia-dysgraphia (6.97 ms, SD=1.09) was significantly (p<0.001) more than that of the normal group (5.05 ms, SD=0.92). The mean related frequency of corrected answers (58.05, SD=4.98%) was less than normal group (69.97, SD=7.16%) (p<0.001).Conclusion: Abnormal temporal resolution was found in children with dyslexia-dysgraphia based on gap-in-noise test. While the brainstem and auditory cortex are responsible for auditory temporal processing, probably the structural and functional differences of these areas in normal and dyslexic-dysgraphic children lead to abnormal coding of auditory temporal information. As a result, auditory temporal processing is inevitable.