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Auditory perceptual and visual-spatial characteristics of subjective tinnitus evoked by eye gaze were studied in two adult human subjects. This uncommon form of tinnitus occurred approximately 4-6 weeks following neurosurgery for gross total excision of space Occupying lesions of the cerebellopontine angle and hearing was lost in the operated ear. In both cases, the gaze evoked tinnitus was characterized as being tonal in nature, with pitch and loudness percepts remaining constant as long as the same horizontal or vertical eye directions were maintained. Tinnitus was absent when the eyes were in a neutral head referenced position with subjects looking straight ahead. The results and implications of ophthalmological, standard and modified visual field assessment, pure tone audio metric assessment, spontaneous otoacoustic emission testing and detailed psychophysical assessment of pitch and loudness are discussed.

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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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Methods and Materials:This cross - sectional analytical study examines the clinical utility of the external ear resonance (EER) peak amplitude measurement as an index of the possible middle ear effusions. The EER peak amplitude and frequency of 180 ears in 98 children of 7-9 years old were recorded. 120 of them (30 girls & 30 boys) had normal hearing and showed type A tympanograms. The remomder (60 ear of 38 boys) showed type B tymoanograms. These children were examined at the clinic of audiology department, rehabilitation faculty, Tehran University of medical sciences and health services, year 1376 hijri.The tests included: 1) Otoscopy, 2) Pure tone air - condition test, 3)Tympanometry and 4) E.E.R peak amplitude and frequency measurement through test - retest.
Results: 1- The average of E.E.R peak frequency for normal hearing girls, normal hearing boys and hearing impaired boys is 3206 Hz (SD=564), 3202 Hz (SI)- 634) and 2953 (SD=37l) respectively.
2- The average of E.E.R peak amplitude is 16.0 dB SPL (SD=2.6), 16.6 dB SPL (SD= 3.0) and 23.5 dB (SD=3.0) for normal hearing girls, normal hearing boys and hearing impaired boys respectively.
3- The correlation of the mean of E.E.R peak amplitude and frequency for two normal groups, girls and boys, is not significant (p>0.0l).
4- The mean test/retest variability in the E.E.R peak amplitude is 16.0 dB SPL and 3.1 Hz for frequency. These results indicate high validity and consistency of E.E.R characteristics measurements.
5- E.E.R peak amplitude is significantly ccre1ated with the presence of type B tympanogram (p-0.00) we find a 6.9 dB SPL increase in average E.E.R peak amplitude in boys with type B tympanograms in comparison to boys with
type A results but correlation of average E.E.R peak frequency of two groups is significant too (p=0.00).
* The results are valid only within the context of this research.
* The results of this research have been compared with similar studies in abroad.

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In order to develop oral communication, hearing impaired infants and young children must be able to hear speech comfortably and consistently. To day children with all degrees of hearing loss may be condidates for some kinds of amlification.As children differ from adults, many Factors should be consider in hearing aid selection, evaluation and fitting. For example the child age when he or she is candidate for custom instruments? Do we consider programmable Hearing aid? Are multi memory instruments appropriate for them? What about directional microphones? What style of hearing aid do we select? In this paper such questions are responded.

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Objective:Determining the prevalence of hearing loss and correlated factors in clients referring to audiology clinic of Buali hospital.
Method and Material: This cross-sectional analytic-descriptive survery was carried out on six thousand and twenty ears of 3010 clients (1651 ,ae amd 1359 female) in Audiology clinic of Buali hospital , during Sept 2000 to Sept 2001.
Results: Hearing loss is the most common reason for referring the clients (20.5%). 1319 ears (21.9%) Showed sensorineural hearing impairment and conductive and mixed hearing loss are observed in 1059 (17.6%) and 234 (3.9%) ears, respectedly. Hearing loss degree most cases is mild (14%) in both ears. There is no significant difference between male and female hearing threshold means (p>0.05) ‘ but a significant difference between hearing thresholds is observed in terms of age (p<0.05). Audiogram configuration in most cases is flat (55.1%). Otoscopic examination reveals abnormal condition in 2333 ears (38.8%) . 37.2% of the studied cases have abnormal tympanogram mostly type B (15.9%). 2.2% of the clients wear hearing aid that mostly have B.T.E ones (1.5%). 6.2% of the clients , depends on their hearing impairment type and degree need rehabilitation services.
Conclusion: The results are Valid only in the context of this study and it&aposs generaliztion needs further researches.

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Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impaired persons.
Materials and Methods: This cross-sectional study was performed on 90 persons with mild to severe sensorineural hearing loss dividing into three groups: 43 subjects were fitted with digital, 15 with programmable, 23 with analog hearing aids. After pure tone audiometry, Abbreviated profile of hearing aid benefit (APHAB) was completed before and one month after using hearing aids to determine the benefit of them.
Results: Global APHAB mean scores for digital, programmable and analog hearing aids were 49.05, 33.19 and 39.53, respectively. Ease of Communication subscale mean scores were 53.46 for digitals, 37.66 for programmables and 39.09 for analogs. Background noise subscale mean scores for digital programmable and analog hearing aids were 46.36, 25.53 and 35.31, respectively. Global and also both subscale mean scores showed significant difference between digital hearing aids and programmable and analog ones. There was no significant difference between reverberation subscale mean scores of three groups.
Conclusion: It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are.

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Background and Aim: Although for a child to maximize his or her mastery of language, hearing aids (HAs) must consistently be worn, and they must be functioning correctly many studies indicates some hearing- impaired children`s hearing aid do not work perfectly.The purpose of this study was to determine types of defects in students&apos hearing aid (HA) in Tehran Exceptional Schools.

Materials and method: In this cross-sectional analytic study defects in sixty –two HAs of 41 children were determined. All were the students of Exceptional Schools referred to Audiology Clinic, Faculty of Rehabilitation Medical Sciences University of Tehran. Functions of the HAs were first checked by a sthetoclips. Then the electroacoustic measurements performed to determine the values of maximum gain and maximum power output. The data were separately recorded in a questionnaire for each kind of the HAs.

Results: Fifty-six percent of HAs functioned perfectly and forty-four percent were not. The most Frequet defects were 24% and 20% pertained to the battery and manual controls respectively. External components had more difficulties than internal components. Seventy percent of ear molds were damaged. There were significant differences between peak of FOG and MPO curves in the catalogue and electroacoustic measurements in 2cc coupler.

Conclusion: Most damaged parts of HAs in Tehran Exceptional students is related to the battery and controls which are external components of HAs. Because of high rate of dysfunctioning HAs and ear molds in this population in this survey, it is necessary to promote orientation and counseling level after fitting and to develop the quality of HAs and ear molds for Exceptional School students.

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Background and Aim: Internal Evaluation means assessment of abilities and potentials. To promote the quality of education, research, health and finally rehabilitation is one of the most important roles and responsibilities of the universities. Promotion of quality of the theoretical and practical education for the Audiology students provides this major with its final goal that is to serve society. The purpose of this study was to evaluate the strength, weaknesses, opportunities and threats (SWOTs) of the Audiology department and to identify the ways of diminishing weaknesses and threats.
Materials and Methods: This descriptive cross-sectional study was conducted on undergraduates, postgraduates, graduates, academic staff, and the director of Audiology department in 9 areas, including management flowchart, educational programs, instructional methods and curriculum models, students, educational areas and equipments, graduate, academic staff, research, and treatment. Data were collected by questionnaires. Results were analyzed descriptively and were expressed in raw and percentage.
Results: The scores of areas in two measures were as follows: management flowchart 4.36 (87.31%), educational programs 4.17 (83.58%), instructional methods and curriculum models 4.01 (80.26%), students 3.43 (68.60%), educational areas and equipment 3.60 (72.11%), from the view of undergraduates, post graduates, faculties, graduates 3.60 (72.03%), academic staff 4.03 (80.6%), research 3.52 (70.4%), and treatment 4.54 (90.80%). The highest score was, therefore, of the treatment area and the lowest belonged to the educational area and equipments. The score of the Audiology department, as the main factor was 3.89 out of 5 which was 77.88%.
Conclusion: Audiology group total score indicates the desirable status that can be promoted to the most desirable if SWOTs are considered.

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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: 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: Patients with migraine commonly show vestibular symptoms. However, abnormal neurotological test findings during the inter-attack intervals, even in the absence of vestibular symptoms, are suggestive of subclinical vestibular dysfunction in migraine. This study aimed to compare the vestibular evoked myogenic potentials between migraine patients and normal individuals.
Methods: Subjects included 25 patients with migraine and 26 healthy volunteers with an age range of 20-53 years old. The vestibular evoked myogenic potentials were recorded with 500 Hz tone bursts at 95 dB nHL.
Results: Mean of absolute amplitude and p13 latency values in the migraine group were significantly less and more than the normal group, respectively (p=0.001 for absolute amplitude in right and left ears p=0.004 for p13 latency in right ears and p=0.02 in left ears). There was no statistically significant difference between the two groups in mean of the n23 latency and also the amplitude ratio (p>0.05).
Conclusion: According to the prolonged latency of vestibular evoked myogenic potentials response, vestibulospinal tract in brainstem is probably involved in migraine patients. However, due to small sample size, for generalizing this result to all patients with migraine, further researches are needed.

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Background and Aim: In many migraine patients prophylactic drugs are effective in reducing attacks and symptoms such as vestibular complaints. Therefore, related neural pathways are probably also affected. This study aimed to compare vestibular evoked myogenic potential in migraine patients under treatment with prophylactic drugs and those without any treatment.
Methods: Subjects included 46 patients with migraine. They were evaluated in two groups those under treatment with prophylactic drugs (21 subjects) and those without treatment (25 subjects). The age range of patients was 20-60 years. The vestibular evoked myogenic potential were recorded with 500 Hz tone bursts at 95 dB nHL.
Results: Mean of amplitude ratio (p=0.02), and interpeak latency values in the right ear (p=0.03) and left ear (p=0.001) were higher in patients with prophylactic therapy than the group without therapy this difference was statistically significant. There was no statistical difference between the two groups in terms of mean of latency of p13 and n23 peaks, and absolute amplitude (p>0.05).
Conclusion: Prophylactic drugs probably improve mean of main response parameters of vestibular evoked myogenic potential in migraine patients with prophylactic therapy.

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Background and Aim: Patients with type I diabetes mellitus commonly complain about dizziness, floating sensation, tinnitus, weakness, and sweating. The aim of this study was comparing vestibular evoked myogenic potentials (VEMPs) between these patients and normal people.

Methods: Twenty-four patients with type I diabetes mellitus and twenty-four healthy volunteers with the age range of 15-40 years were enrolled in this study. A tone burst of 500 Hz, with the intensity of 95 dB nHL, was delivered through a insert earphone and vestibular evoked myogenic potential was recorded. The t-test was used to compare the results between the two groups. To investigate the effect of glycated hemoglobin (HbA1c) on VEMP responses (latency, absolute and relative amplitude), the regression analysis was used.

Results: The mean p13 and n23 latency were significantly more in patients with type Ι diabetes mellitus (for P13 latency, p=0.013 in right and p=0.010 in left ear, and for n23 latency, p<0.001 in right and p=0.005 in left ear). There was no significant difference between two groups in absolute and relative amplitude and prevalence of the VEMP (p>0.050). There was no correlation between VEMPs and HbA1c in patients with type 1 diabetes mellitus (p>0.05).

Conclusion: Prolonged latencies of the VEMP in patients with type 1 diabetes mellitus suggest lesions in the retrolabyrinthine, especially in the vestibulospinal tract. Nevertheless, due to the limited number of examined samples, further investigation with more patients should be performed.

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Background and Aim: Non-linear frequency compression is a new feature in hearing instruments compresses the voices of a high-frequency region above a certain cut-off point and transfers them to the lower frequency regions in order to improve the audibility. In this study, we aimed to survey the effect of this feature on the total level of hearing skills of children with profound hearing loss at the age of 3-4 years.

Methods: Twenty two 3-4-years-old children with profound hearing loss were selected with improbable simple sampling. 11 of them had hearing instruments with non-linear frequency compression and 11 had traditional hearing instruments. Tavana test (Jarollahi, 2009) was used to compare the level of hearing skills in these two groups.

Results: Comparison of mean scores of total level of hearing skills in two groups indicated a significant difference (p <0.001). Also, the mean scores of level in all subtests, detection (p=0.022), determination (p=0.005), recognition (p=0.039) and comprehension (p=0.010), showed significant differences.

Conclusion: Using the hearing instruments with non-linear frequency compression would increase the total level of hearing skills in children with profound hearing loss at the ages of 3-4-years and also, in all skill of detection, determination, recognition and comprehension.

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Background and Aim: Setting of candidates for a word with similar beginnings is known as the Cohort size. Despite the importance of the number and properties of candidates in word recognition, so far, in none of the tests made for Persian language, the Cohort size is considered. The purpose of current study was the introduction of importance of Cohort size in word recognition and calculation of Cohort size for the list of Persian high-frequency spondee words.

Methods: The spondee words extracted from high-frequency Persian word store. Then, total spondee words with same first syllable in Amid Persian dictionary recorded and Cohort size calculated for each spondee word. Thus, the list of high-frequency spondee words with their Cohort size composed of 4121 words obtained.

Results: The Cohort sizes of word had a wide range from 0 to 87. In the half of the words, the Cohort sizes were less than 14 and in the rest were more than it.

Conclusion: The Cohort size affects the time course and precision of decision making about words. Persian words are not equal in Cohort size. For having more controlled test materials to develop and design different types of auditory tests, it is possible to consider the Cohort size of words along other effective factors.