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We aimed at discussing some common auditory disorders in children with dyslexia. In such patients delayed reading, memory dysfunction, spatial and visual perception and hearing abnormalities are reported with various degrees.Investigations have not led to distinct findings about the etiology of the abnormality. We will discuss this abnormality with an audiological point of view.

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Vestibular Schowanoma is one of the most common Intracranial Tumors which has elicited from the Schwann cells in the upper part of vestibular branch of 8^th nerve and can affect the cochlear branch too. This benign capsulated tumor  is mostly unilateral. Schowanoma is relatively slow growing.In the current article we have presented the case of a 51 year-old woman complaining Right ear Tinnitus accompanying with numbness of the right side of the face without any sign of vertigo or imbalance. MRI and Auditory Brain stem Responses (ABR) studies demonstrated right side vestibular Schowanoma next to cerebellopontine Angle (CPA). The audiological and imaging findings have been brought here in details.

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Objectives: Introducing an approach for diagnosing the normal ABR independently or supplementary used to confirm the results of the other approaches.
Materials and Methods: This study was carried out in a descriptive manner on 31 male students of audiology in the Rehabilitation Faculty which were not chosen randomly. All of the samples aged between 18 to 25 years old with normal hearing and with no history of hearing disorder. They were tested in the winter of 1377 by ABR. The resulted of their ABR tests (62 curves) were in accordance with the convenient latency norms. After the preparation stage, the frequency analysis of the curves was considered through the Fast Fourier Transform function.
Results: considering the power and phase spectrum, three components are recognized, and phase for their frequency, amplitude and phase are determined.The normative values of the obtained amounts of the frequency, amplitude and phase for the frequency analysis results of the normal ABR curves are as follows:* First Component: Frequency: 340-530 Hz, Amplitude: 23-31 dB, Phase: 0-3 radian * Second Component: Frequency: 540-370 Hz, Amplitude: 20-30 dB, Phase: 0.3-2.7 radian * Third Component: Frequency: 750-1024 Hz, Amplitude: 19-30dB, Phase: 0-3.3 radian
onclusion: The results of the present study are exclusively valid for the society being considered, and their generalization requires more researches.

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Rehabilitation of deaf individual is one of the important subjects that has attracted attention of many researchers during past centuries. Different opinions have been established in this direction. Electrophysiologic tests were established and developed parallel to developments in rehabilitation. Therefore, opinion of using electrophysiologic test for evaluation and fitting of hearing aid became gradually popular. Ultimately, the electrophysiologic tests are used in evaluation and fitting of hearing aid in two ways:1-Direct way2- Indirect wayIn direct way aided ABR is obtained and special attention is paid to wave V. This technique has many difficulties. Inindirect way, electrophysiologic tests such, ECochG, OAE and ABR, AMLR, ALR and P300 and other objective tests are used, especially in infants and neonates for evaluating the state of hearing. Researches are continuing in this field. It is probable to have aided electrophysiologic responses with speech stimuli in near future.

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Arachnoid cysts are cerebrospinal fluid-filled sacs that are located between the brain or spinal cord and the arachnoid membrane, one of the three membranes that cover the brain and spinal cord. They are usually located within subarachnoid space with a membrane consisting of arachnoid cells and collagen fibers and are filled with CSF. It is naturally considered as a congenital cyst because of its common appearance in the infancy. Typical symptoms of an arachnoid cyst around the brain include headache, nausea and vomiting, seizures, hearing and visual disturbances, vertigo, and difficulties with balance and walking. MRI and CT can help in diagnosis. Arachnoid cysts are benign and the vast majority remains asymptomatic throughout life. If they are deemed to be causing symptoms then surgery can be contemplated. Here, we are aimed at describing a case of Arachnoid cysts involved cerebellopontine angle that has been reffered to audiology clinic in Tehran University of Medical Sciences. The experiments and results of radiographic techniques has been brought here.

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Objective: This study was aimed to survey the hearing status of the patients with definite MS. The results of this study may help to confirm the diagnosis and to improve our knowledge of different aspects of this disease and to optimize the treatment and rehabilitative techniques.
Material & Methods: This study is performed in audiology clinic of rehabilitation science faculty of Iran medical science university as an assesive-analytic procedure in winter of 2000 in 40 MS patients (Referred from the MS clinic of Shohada Hospital) of 20 to 45 years old. All the patients have no history of otologic problems. The results of conventional audiologist tests (PTA, SRT, SDS, imittance audiometry) and ABR findings of MS patients were compared to the results of control group.
Results: The differences between the means of low, high and mid frequency PTAve in MS patients and control group were statistically significant (P<0.05). There was no significant difference between two groups in the speech test&aposs results, statistically. The results of ART test show statistically significant differences between experimental and control groups. The only differences in ABR results were seen for the absolute latency of the wave V and IPLs (I-V, III-V) between two groups. The amplitude ratio of V/I in MS patients 1.5 was within the normal range (0.5 to 2). There was a statistically significant relationship between mean of mid frequency PTAve and prolongation of absolute latency of the wave V. The relationship between ABR and SDS and also between ART and ABR were not statistically significant. Finally, the results of this study suggested that low, high and mid frequency PTAve, ART, absolute latency of the wave V, and IPLs III-V, I-V can be used ascomplementory method to confirm the diagnosis of MS with other conventional methods such as: MRI, CSF analysis, SEP and VEP.

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Objective : To assess neonates and children suffering from meningitis , during the critical and recovery periods , using ABR , EOAE and Behavioral Audiometry.
Method and Material: 40 neonates to 12-year-old children were assessed. Using ABR test, the hearing of these cases was evaluated during the critical period-that is , 24-72 hours following the diagnosis. This test was repeated when patients recovered from meningitis-that is 24 hours before discharge (recovery period) Hearing function , again , was assessed 7-14 days following discharge through Immittance Audiometry, Behavioral Audiometry (PTA , SF and BOA). And EOAE (TEOAE and DPOAE) tests procedures.Findings: During the critical period , ABR test revealed normal hearing in 35 patients (87.5%) and severe to profound sensorineural hearing loss (unilateral and bilateral) in 5 patients (12.5%-girl=4, boy=1). The same result were obtained in re-evaluation in the recovery period. On the other hand , 7-14 days after of discharge , Immittance Audiometry and Behavioral Audiometry (including PTA , S.F and BOA tests), confirmed the mentioned results (cross - gcheck). EOAE test (DPOAE and TEOAE) in 35 normal hearing patients (according to ABR test) , showed normal cochlear function. 2 out of 5 cases suffering from severe to profound sensorineural hearing loss revealed normal cochlear function. According to EOAE results , abnormal cochlear function was evident in 3 patients.
Conclusion: ABR , EOAE tests , and Behavioral Audiometry in children meningitis during the critical period and recovery period can be used to diagnose any degree of hearing loss with a high level accuracy. The results of persent study is confirmed by previous investigations.

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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.

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Background and Aim: Hyperbilirubinemia is one of the most common abnormalities during the neonatal period. Approximately 60% full-term and 80% preterm neonates suffer from hyperbilirubinemia. Hearing loss is one of the most prevalent side-effects of hyperbilirubinemia. This happens when the serum concentration of indirect bilirubin increases dramatically. The main purpose of this study is to evaluate the hearing status and to diagnose the probable site of lesion in affected children.
Materiads and Methods: In this cross-sectional study, 33 newborn to two year old subjects uffering from hyperbilirubinemia were evaluated using auditory brainstem response (ABR) and transient evoked otoacoustic emissions (TEOAE) tests In the Audiology department of the Faculty of Rehabilitation Sciences Iran University of Medical Sciences sampling method was accessible.
Results: 21% of the subjects had severe to profound hearing loss and 9% of subjects had mild to moderate hearing loss. In 51% of the subjects there was no response to ABR and TEOAE tests indicating cochlear and/or retrocochlear lesion. The other 15% manifest only abnormal ABR test indicating the presence of the auditory neuropathy.
Conclusion: TEOAEs test has its own limitations in these subjects, that is the hearing status of such patients can not be completely evaluated by using just TEOAE test. Therefore, to detect hearing loss both ABR and TEOAE tests must be performed in these subjects.

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Background and Aim: Physiologic measures of cochlear and auditory nerve function may be of assistance in distinguishing between hearing disorders due primarily to auditory nerve impairment from those due primarily to cochlear hair cells dysfunction. The goal of present study was to measure of cochlear responses (otoacoustic emissions and cochlear microphonics) and auditory brainstem response in some adults with auditory neuropathy/ dys-synchrony and subjects with normal hearing.
Materials and Methods: Patients were 16 adults (32 ears) in age range of 14-30 years with auditory neuropathy/ dys-synchrony and 16 individuals in age range of 16-30 years from both sexes. The results of transient otoacoustic emissions, cochlear microphonics and auditory brainstem response measures were compared in both groups and the effects of age, sex, ear and degree of hearing loss were studied.
Results: The pure-tone average was 48.1 dB HL in auditory neuropathy/dys-synchrony group and the frequency of low tone loss and flat audiograms were higher among other audiogram&aposs shapes. Transient otoacoustic emissions were shown in all auditory neuropathy/dys-synchrony people except two cases and its average was near in both studied groups. The latency and amplitude of the biggest reversed cochlear microphonics response were higher in auditory neuropathy/dys-synchrony patients than control people significantly. The correlation between cochlear microphonics amplitude and degree of hearing loss was not significant, and age had significant effect in some cochlear microphonics measures. Auditory brainstem response had no response in auditory neuropathy/dys-synchrony patients even with low stimuli rates.
Conclusion: In adults with speech understanding worsen than predicted from the degree of hearing loss that suspect to auditory neuropathy/ dys-synchrony, the frequency of low tone loss and flat audiograms are higher. Usually auditory brainstem response is absent in this patients and use of both otoacoustic emissions and cochlear microphonics responses to measure cochlear hair cells function are suggested in them.

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Background and Aim: Hyperbilirubinemia during the neonatal period is known to be an important risk factor for neonatal auditory impairment, and may reveal as a permanent brain damage, if no proper therapeutic intervention is considered. In the present study some electroacoustic and electrophysiologic tests were used to evaluate function of auditory system in a group of children with severe neonatal Jaundice.
Materials and Methods: Forty five children with mean age of 16.1 14.81 months and 17 mg/dl and higher bilirubin level were studied, and the transient evoked otoacoustic emission, acoustic reflex, auditory brainstem response and auditory steady-state response tests were performed for them.
Results: The mean score of bilirubin was 29.37± 8.95 mg/dl. It was lower than 20 mg/dl in 22.2%, between 20-30 mg/dl in 24.4% and more than 30 mg/dl in 48.0% of children. No therapeutic intervention in 26.7%, phototherapy in 44.4%, and blood exchange in 28.9% of children were reported. 48.9% hypoxia and 26.6% preterm birth history was shown too. TEOAEs was recordable in 71.1% of cases. The normal result in acoustic reflex, ABR and ASSR tests was shown just in 11.1% of cases. The clinical symptoms of auditory neuropathy were revealed in 57.7% of children.
Conclusion: Conducting auditory tests sensitive to hyperbilirubinemia place of injury is necessary to inform from functional effect and severity of disorder. Because the auditory neuropathy/ dys-synchrony is common in neonates with hyperbilirubinemic, the OAEs and ABR are the minimum essential tests to identify this disorder.

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Background and Aim: One of the most important problems of children who suffer from autism is abnormality in receiving and integrating sensory inputs, especially hearing input. It has been shown that brainstem has a key role in receiving, encoding and integrating hearing input. Auditory brainstem response (ABR) is a tool by which we can evaluate this function. The purpose of this study was to assess and to compare autistic and normal children brainstem hearing function.
Materials and Methods: This case-control study was conducted on thirty (58 ears) autistic and thirty (57 ears) normal 6-12 years old children. The children with autism were divided into slight and severe subgroups according to Autism Diagnostic Interview-Revised questionnaire. Click-evoked ABR was recorded and compared between groups.
Results: There was significant difference between two groups V and III wave latencies and I-III and I-V interpeak latencies (p<0.05). In fact, comparison of the results of autism subgroups with normal children indicated that the latencies of the severe subgroup significantly prolonged.
Conclusion: Increasing latencies of ABR waves in severe subgroup maybe due to abnormality in low level of brainstem. Brainstem abnormality may result in exacerbating the symptom of autism. It is therefore suggested that ABR is included in diagnostic test batteries for these patients.

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Background and Aim: Blocking of the adenosine receptor in central nervous system by caffeine can lead to increasing the level of neurotransmitters like glutamate. As the adenosine receptors are present in almost all brain areas like central auditory pathway, it seems caffeine can change conduction in this way. The purpose of this study was to evaluate the effects of caffeine on latency and amplitude of auditory brainstem response(ABR).
Materials and Methods: In this clinical trial study 43 normal 18-25 years old male students were participated. The subjects consumed 0, 2 and 3 mg/kg BW caffeine in three different sessions. Auditory brainstem responses were recorded before and 30 minute after caffeine consumption. The results were analyzed by Friedman and Wilcoxone test to assess the effects of caffeine on auditory brainstem response.
Results: Compared to control group the latencies of waves III,V and I-V interpeak interval of the cases decreased significantly after 2 and 3mg/kg BW caffeine consumption. Wave I latency significantly decreased after 3mg/kg BW caffeine consumption(p<0.01).
Conclusion: Increasing of the glutamate level resulted from the adenosine receptor blocking brings about changes in conduction in the central auditory pathway.

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Background and Aim: Tinnitus is an unpleasant sound which can cause some behavioral disorders. According to evidence the origin of tinnitus is not only in peripheral but also in central auditory system. So evaluation of central auditory system function is necessary. In this study Auditory brainstem responses (ABR) were compared in noise induced tinnitus and non-tinnitus control subjects.
Materials and Methods: This cross-sectional, descriptive and analytic study is conducted in 60 cases in two groups including of 30 noise induced tinnitus and 30 non-tinnitus control subjects. ABRs were recorded ipsilateraly and contralateraly and their latencies and amplitudes were analyzed.
Results: Mean interpeak latencies of III-V (p= 0.022), I-V (p=0.033) in ipsilatral electrode array and mean absolute latencies of IV (p=0.015) and V (p=0.048) in contralatral electrode array were significantly increased in noise induced tinnitus group relative to control group.
Conclusion: It can be concluded from that there are some decrease in neural transmission time in brainstem and there are some sign of involvement of medial nuclei in olivery complex in addition to lateral lemniscus.

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Background and Aim: High incidence of speech disorders in children with cerebral palsy could be related to a deficiency in processing of auditory stimuli. So it is vital to check out any peripheral or central disorders in auditory system using behavioral and electrophysiological auditory tests.
Methods: In a cross-sectional study, 15 children with spastic diplegia, mean age 5.77, SD 2.26 years, and 15 normal children, mean age 5.33, SD 1.80 years, were tested using pure tone audiometry, immittance and auditory brainstem responses. The results were compared between the two groups.
Results: Hearing thresholds and middle ear status were in normal range in all participants however, contralateral acoustic reflex thresholds were mostly elevated. Comparing absolute latency and interpeak latency intervals of auditory brainstem responses between the two groups, absolute latency interval of later waves, and in specific the V wave, was significantly longer in diplegic children (p=0.04) resulting in a longer III-V interpeak latency intervals (p=0.02).
Conclusion: Neurological disorders in ponto-reticulo-spinal pathway, pontine reticular nuclei and upper pons which are adjacent to auditory nuclei of lateral leminiscus and inferior colliculus result in auditory dys-synchrony and increased latency intervals in latter waves of auditory brainstem responses. This could also attributed to functional disorders in wave-generating sites in these patients.

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Background and Aim: In view of improvement in therapeutic outcome of cancer treatment in children resulting in increased survival rates and the importance of hearing in speech and language development, this research project was intended to assess the effects of cisplatin group on hearing ability in children aged 6 months to 12 years.
Methods: In this cross-sectional study, hearing of 10 children on cisplatin group medication for cancer who met the inclusion criteria was examined by recording auditory brainstem responses (ABR) using the three stimulants of click and 4 and 8 kHz tone bursts. All children were examined twice: before drug administration and within 72 hours after receiving the last dose. Then the results were compared with each other.
Results: There was a significant difference between hearing thresholds before and after drug administration (p<0.05). Right and left ear threshold comparison revealed no significant difference.
Conclusion: Ototoxic effects of cisplatin group were confirmed in this study. Insignificant difference observed in comparing right and left ear hearing thresholds could be due to small sample size. auditory brainstem responses test especially with frequency specificity proved to be a useful method in assessing cisplatin ototoxicity.

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Background and Aim: Preterm birth is one of the risk factors need comprehensive audiological assessment. In this study, the effect of sex and rate of stimulation on response of children with history of preterm birth was investigated by auditory brainstem response (ABR).

Methods: This cross-sectional study was conducted using convinience sampling. Click-evoked a uditory brainstem response test with both low (21.1 c/s) and high (51.1 c/s) stimulus rates was recorded in 30 children with a history of preterm birth and 30 ones with history of term labor, as controls.

Results: Significant differences were observed in inter-peak latencies of I-III in both rates, III-V in the low rate, I-V in the high rate, and absolute latency of III wave between high and low stimulus rates (p<0.05 for all). Rate of stimulus affect on auditory brainstem response of preterm birth group was more than controls. Sex also affected on some parameters of auditory brainstem response test.

Conclusion: Preterm birth group showed longer latencies than normal group in both rates. Rate of stimulus had significant effect on results of children with history of preterm birth compared normal group. These findings may reflect the negative effect of preterm birth on neural synchronization function in response to transient stimuli.

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Background and Aim: Diabetes mellitus is a progressive metabolic disease. Studies about the relationship between diabetes mellitus and auditory impairment have shown variable results in supporting the fact that diabetes may have a complex repercussion on the auditory pathways. We aimed to evaluate hearing in patients with type II diabetes mellitus with behavioral and electrophysiological auditory tests.

Methods: In a cross-sectional study, we assessed 30 patients with type II diabetes mellitus with the mean age of 43.7 (SD: 1.3) years, ranging 40-45 years, and 30 matched healthy subjects with the mean age of 41.5 (SD: 1.5) years. Subjects were evaluated using auditory brainstem response (ABR) and pure tone audiometry. The results were compared between two groups.

Results: Pure tone audiometry was normal. There was a significant increased latency for waves I, III, and V, and also, interpeak latencies of I-III, III-V, and I-V waves (p<0.05).

Conclusion: ABR latency prolongation indicates abnormal nerve conduction velocity in patients with type II diabetes mellitus. ABR can be an important clinical tool for evaluating diabetes influence on cochlear nerve conduction velocity before hearing loss occurs in these patients.

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Background and Aim: Omega-3 fatty acid have structural and biological roles in the body 's various systems . Numerous studies have tried to research about it. Auditory system is affected a s well. The aim of this article was to review the researches about the effect of omega-3 on auditory system.

Methods: We searched Medline , Google Scholar, PubMed, Cochrane Library and SID search engines with the "auditory" and "omega-3" keywords and read textbooks about this subject between 19 70 and 20 13.

Conclusion: Both excess and deficient amounts of dietary omega-3 fatty acid can cause harmful effects on fetal and infant growth and development of brain and central nervous system esspesially auditory system. It is important to determine the adequate dosage of omega-3.

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Background and Aim: Studies have shown that long-term use of monaural hearing aid in symmetrical hearing losses may lead to physiological changes. In this research, the possibility of plasticity occurrence in bilaterally hearing impaired listeners fitted with only one hearing aid was investigated.

Methods: Our study was carried out on 12 elderly listeners with a mean age of 61.92 years who had symmetrical moderate to severe sensory neural hearing loss in both ears. All of the participants had minimum monaural hearing aid experience of 2 years. We used auditory brainstem response (ABR) testing in order to compare absolute latency and amplitude of wave V between the two ears of cases. Air conduction click stimuli were presented monaurally at 80, 90 and 100 dB nHL.

Results: Despite the shorter absolute latency of wave V in the fitted ear, no significant difference was found between the two ears (p>0.389). The difference between wave V amplitude of both ears was greater in 90 dB nHL level (p=0.043). Women showed shorter mean latency than men and the mean amplitude of women was greater than men. Significant gender difference was observed in absolute latency of wave V (p<0.037).

Conclusion: Our findings indicate that the use of monaural hearing aid in symmetrical hearing losses can induce neural plasticity within auditory brainstem pathways which can be displayed by auditory brainstem response test.