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Background and objectives: This article is aimed at: 1.studying the relationship between Bone conduction pure tone thresholds and speech reception thresholds via bone conduction in normal patients 2.studying the stability and repeatability of the speech reception thresholds via bone conduction and 3. Comparing the characteristics of the function of the speech gain via bone conduction with that of air conduction.
Method: 60 normal hearing subjects (30 males and 30 females) were evaluated by air conduction pure tone audiometry, bone conduction pure tone audiometry and speech reception thresholds.
Results: Findings for the mentioned tests in all subjects were statistically insignificant. The results are prepared in tables and charts.
Conclusion: Pure tone thresholds and speech reception thresholds acquired by means of air conduction testing and bone conduction testing and the stability and repeatability were similar in both evaluations.

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Materials and Methods: This study was performed in two parts: included development and standardization of the test and the second part was the evaluation stage. In the first section, Watson&aposs crieria fpr valid speech recognition tests for children was considered. In order to balance the lists phonemically, it was necessary to determine Persian phonemes&apos frequency -of- occurences. Thus, the frequency -of- occurences for 29 phonemes of Persian language in children&aposs and adults&apos speech were separately determined. There were significant differences between some phonemes&apos frequencies in the two samples. So&apos their frequencies in children&aposs speech was used to design the test. It should be mentioned that each list could contains only 25 vowels, while almost 32 ones were meeded according to the phonemically balancing procedure. Therefore, vowels and consonants were separately balanced. The required monosyllabic words were extracted from the books written for 4 to 6 years old children. Finally, four closed set (3- picture matrix) 25 word lists were prepared. The lists were recorded on magnetic cassette in one of the IRIB studios.To assess the test validity and reliabity, 33 normal hearing children were randomly selected from kindergartens over the city of Tehranand were tested at the Audiology Clinic of the Rehabilitation Faculty, Tehran University of Medical Sciences in 1998. The tests included: otoscopy, pure tone & immittance audiometry, establishing speech reception threshold, and speech recognition test - retest by these lists.
Findings: 1- Normal hearing children obtained 92-100 percent scores for each list at their most comfortable loudness levels through test - retest.
2- No significant difference was observed in test - retest scores in each list (p>0.05).
3-No significant difference obtained between the lists test or retest scores (p>0.O5).
4-No significant difference was observed between children&aposs scores in terms of their age and gender (p>O.OS)
Conclusion: this study, therefore, is reliable and valid. The lists are phonemically balanced and equal in difficulty. Due to the conditions under which the test was designed (including, phonemic balance, necessity of using the words that could be pictured and of the presence of tow other word in children&aposs vocabulary which is similar in auditory aspects), only the content validity for word familiarity decreased a little that could be overcome by introducing them through pictures prior to the start of the test.

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Method and Materials: This cross - sectional survey is carried out in pediatric clinic department of audiology faculty of rehabilitation, TMSU, on spring 1998. 102 top grade ranking children with normal hearing threshold

Results:1- The thresholds were not significantly different at any frequency (P>0.05) in test re-test trials.
2- The test minus re-test threshold for individual ears showed clinically reliable and acceptable range 0-10dB SPL for at least
99.74% of the ears at all frequencies.
3- The threshold differences between right & left cars in two test sessions were not significantly different (P>0.05) except for 14KHz.
4- High- frequency threshold in two test sessions showed no significant difference between girls & boys at all frequencies (P>0.05) (except for 16 & 20 KHz in right ear and 10 KHz in left ear).
Conclusion: This test can be used for evaluation of individual high-frequency threshold in all frequency as test re-tests tria1. Moreover, this test may use as a beneficial tool for monitoring different endogenous and exogenous auditory pathologies.
Consideration: it is found that this research is valid only among situation of this project. Any generalization needs further research.

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Objective: Determining the frequency of hearing disorders and hearing aid using in the clients referring to the Avesina education and health center, audiometry clinic, 1377.
Method and Material: This is an assesive-descriptive survey that conducted on more than 2053 (1234 males and 819 females) who referred for audiometry after examination by a physician. Case history, otoscopy, PTA, speech and immittance audiometry were conducted for all the clients. The findings were expressed in tables and diagrams of frequency. The age and sex relationship. All types of hearing losses and the number of the hearing-impaired clients need a hearing aid were assessed.Findings: 56% of this population were hearing-impaired and 44% had normal hearing were hearing. 60% were males and 40% females. Of the hearing-impaired, 44% had SNHL, 35.6% CHL and 8.2% mixed hearing loss. The hearing aid was prescribed for 204 (83 females and121 males) if they need that only 20 females and 32 males wear it.
Conclusion: It this sample, SNHL is of higher frequency. According to this survey, the more the age, the more the hearing aid is accepted (85% of wearer are more than 49) the prevalence of the hearing impaired males are more than females (60% versus 40%). Only 25% of the hearing-impaired wear hearing aids.

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Method & Material: This descriptive analytical survey was performed in pars Hospital, Tehran on 45 children (22 girls, 23 boys aged 2-5 years, 1377-78 (solar).Finding: In 2-3 years old group, accurdacy of PTA test (87/7%) was more than FNS test (66%). In 3-5 years old group, Specificity & NPV showed no significant differences, between two test.
Conclusion: Since the PTA showes greater possibility of false positive response than FNST, the accuracy of the latter test is greater the PTA.

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Background and Aim: Hearing sensitivity is so vital for musicians as loud music can cause hearing loss. The aim of this study was to assess hearing sensitivity of musicians in order to determine the effects of music exposure on hearing organ.
Materials and Methods: This case-control study  was conducted on 15 string musicians with musicianship history of more than 10 years and 15 normal hearing subjects. They all were male and 20-30 years old. TEOAEs and DPOAEs performed after otoscopy , immittance and pure tone audiometry in octave frequencies between 250 to 16000 Hz.
Results: There is not significant difference between pure tone thresholds of two groups for all frequencies.A significant difference of TEOAE is found between two groups for total response and amplituds of TEOAEs . DPOAEs amplituds are not significantly different between two groups .
Conclusion: Musicianship may  affect TEOAEs amplitudes , but cannot affect results of PTA and DPOAEs. Therefore this can be useful to detect cochlear lesions secondary to music exposure and also as a tool in hearing protection program.

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Background and Aim:  Among all auditory assessment tools, auditory steady state response (ASSR) is a modern test. Modulation frequency for this test is usually 80 Hz. The purpose of this study, was to examined adult subjects with 40 Hz and 80 Hz ASSR and compare the results.
Materials and Methods: Thirty adult (60 ears) were evaluated by ASSR and PTA test, Results were divided into three groups: normal hearing, mild and moderate sensorineural hearing loss.
Results: In all groups, forty hertz ASSR thresholds were relatively closer to behavioral threshold than those of 80 Hz ASSR(p<0.05). Besides, the more severe hearing loss, the lower the difference between those two thresholds. Correlation coefficients were also higher in 40 Hz ASSR(p<0.05).
Conclusion: Frequency modulation thresholds with 40 Hz are more likely to be closer to the behavioral thresholds. Moreover, it has better results than the thresholds with 80 Hz.

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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: The auditory steady state response is a modern test for estimating hearing thresholds, especially in difficult to test individuals . However, there are few bone conduction auditory steady state response data, particularly for individuals with hearing loss. The objective of this study was to investigate bone conduction auditory steady state response thresholds in individuals with sensorineural hearing loss and normal hearing.

Methods: In a cross-sectional study, 10 individuals with normal hearing and 10 with sensorineural hearing loss at the age of 15-30 years were selected by non-probability sampling. Auditory steady state response and pure tone audiometry to bone conduction stimuli in 500 and 2000 Hz were recorded in two groups. Paired and independent t-test were used to compare data between the groups.

Results: There was low correlation between bone conduction auditory steady state response and pure tone audiometry in both groups (p>0.05 for both). The difference of behavioral thresholds and auditory steady state response in 500 Hz was higher than 2000 Hz in both groups (p=0.033 for normal hearing and p=0.017 for sensorineural hearing loss groups). Comparison of these results showed significant differences between the two groups (p<0.001).

Conclusion: In both groups, there was low correlation between bone conduction auditory steady state response and pure tone audiometry thresholds. In individuals with sensorineural hearing loss and in higher frequencies , bone conduction auditory steady state response thresholds was closer to pure tone audiometery thresholds.