---

Background and Aim: The auditory system changes by increasing age in both central and peripheral parts. The purpose of this study was to  investigate the effect of the increasing the stimulus rate on auditory brainstem response (ABR)  waves latency in old population with normal hearing.
Materials and Methods : In this cross-sectional study click ABR test performed on 20 young normal-hearing subject with mean age of 20.8 years old and 10 old normal-hearing subject with mean age of 66.4 years old. ABR results with different stimulus rates were compared between two group.
Results : ABR peak latencies and interpeak intervals were prolonged with increasing the click repetition rate. Peak latencies were slightly prolonged in older adults and the I-V interval did not differ with age but prolongation of  III-V interval were significantly differs in older population compared to young adults.
Conclusion : Using high click rates may sensitize the ABR to the identification. of lesions of auditory nerve or brainstem , but before that , we need to know the normal range of different age groups , so that we can decide about probability of a retrocochlear lesion.

---

Background and Aim: Neuroimaging techniques in audiovisual speech processing are innovative approach to neuroscience investigation that steadily influences the deep survey of highly mechanisms involved in this process. The purpose of this study was to evaluate brain activity via functional magnetic resonance imaging throughout audiovisual speech perception in Persian language.
Methods: Functional MRI was used to assess 19 normal 20-30 year old women while they had been presented syllable /ka/ visually and /pa/ auditory using block design method, in which it would provide two series of imaging, functional and T1-weighted. Subsequently, the results were analyzed and compared by FSL software.
Results: The results of this study pointed out that both middle and cortical regions of brain are activated in visual stimuli and its middle regions are activated in response to auditory stimuli. Hence, left anterior supramarginal, some parts of motor speech system including insular and cingulate cortex-precentral cortex were stimulated with visual stimulus and left posterior supramarginal as well as right supramarginal gyrus were stimulated with auditory stimulus. Moreover, in this investigation, McGurk effect was behaviorally proven in fifteen subjects.
Conclusion: It was hypothesized that the activation of unique region, supramarginal gyrus, with both audio and visual stimuli indicated the presence of commonplace region for phonologic processing of sensory inputs. In addition, auditory stimuli develop more intense activity and on the other hand, broaden-maximum voxel-as well as extra regions are demonstrated in response to visual stimuli. These points represent the unfamiliarity of normal individual brain to percept visual speech stimuli.

---

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.