Hearing function can affect communication skills and especially speech and language abilities.As a result, most of the attempts in behavioral audiometry have focused on the improvement and rectification of the techniques for hearing evaluations of the infants and children.Crib-O-gram and the methods suggested by northern & Downs are some of the mentined protocoles.

For years a significant advance for evaluating hearing sensitivity of children have been taken place. say, behavoral visual audiometry, VRA, TROCA and play audiometry. some studies also have been performed regarding to the use of BOA technique in mental retarded children and its success in evaluating hearing sensitivity in such children.other protocoles use rewarding thechniques for reinforcing child's responses which have been demonstrated to be success in the evaluation.

In addition,by comparying the results of frequency and intensity discrimination (by means of Luescher test), the changes in the resonance frequency of the outer ear and loudness conmfortable level(LDL), one can study the process of hearing development in children.

Hearing function can affect communication skills and especially speech and language abilities.As a result, most of the attempts in behavioral audiometry have focused on the improvement and rectification of the techniques for hearing evaluations of the infants and children.Crib-O-gram and the methods suggested by northern & Downs are some of the mentioned protocols.For years a significant advance for evaluating hearing sensitivity of children have been taken place. say, behavioral visual audiometry, VRA, TROCA and play audiometry. some studies also have been performed regarding to the use of BOA technique in mental retarded children and its success in evaluating hearing sensitivity in such children.other protocols use rewarding techniques for reinforcing child's responses which have been demonstrated to be success in the evaluation.In addition,by comparing the results of frequency and intensity discrimination (by means of Luescher test), the changes in the resonance frequency of the outer ear and loudness comfortable level(LDL), one can study the process of hearing development in children.

In the current article we will have a look at the evolution of audiological tests. Based on the Olsen's theory, having knowledge about the history of audiological evaluation is not a platitudinous issue, Rather an audiologist should have a comprehensive knowledge about it and be involved in its progress. In this way he can attain enough expertise and science to make use of the technology.The oldest history regarding to this issue goes back to the 16th century, although It should be considered that other related investigations about sound, hearing and related fields has heretofore been performed and the relevant investigators should not be ignored.

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.

Objectives: The current study was performed to establish the prevalence rate of hearing disorders in school age children.
Method: This study has been performed in a randomized manner among 1000 school-age children (500 girls and 500 boys) in the years between1976-1997 in Behbehan. All subjects underwent Audiometric evaluations, Otoscopy, and impedance audiometry. Additionally, parents, children and teachers were interviewed or asked by questionnaires regarding the familial status of parents, familial history of any hearing loss and the awareness of suffering hearing loss. The findings have been prepared in the charts and tables and the relationship between age and gender of the subjects with the incidence of hearing loss has been evaluated via the statistical test X² and hearing loss in left and right ear was compared by T-test.
Results: the findings demonstrated that 6.6% of the subjects suffered hearing loss in one ear (2.2%) or both ears (4.3%). 4.8% of the patients suffered conductive hearing loss while 1.6% suffered sensory-neural hearing loss. In .2% patients complained different types of hearing loss in the ears. Hearing loss was mostly slight and the relationship between age and gender with the incidence of hearing loss was not statistically significant.
Conclusion: Based on the findings we have concluded that in18.4% of the subjects, medical treatment was required and 0.7% of them were in need of rehabilitation. The percentage of the awareness of the hearing disorders among children, parents and teachers was 21.2%, 22.7% and 15.2% respectively.

Introduction: We estimated the noise in an industrial shoe factory to determine the effect of noise in the workplace on the hearing status of the workers in such environments.
Materials and method: the intensity of noise in dB in different parts of the factory was estimated. Then working people in each part was selected randomly and their hearing thresholds were evaluated by Conventional audiometry.
Results: The results demonstrated that 23% were required to estimate thresholds more precisely and 95 needed close examination by Otolaryngologist. Besides, 10% of the workers suffered sensory neural hearing loss whose 2% of them diagnosed as NIHL.
Discussion: Since the mentioned factory has good hearing conservation program for the workers, it seems that promoting the program can decline the number of noise induced hearing losses to the least numbers.

Objectives :Determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, impedance Audiometry and questionnaires.
Methods and Materials: This study was can-led out in a cross - sectional descriptive survey - on 1000 students (500 girls and 500 boys) among the student of primary school of EslamAhad Gharh, academic year 1376-77
Results: 1- Otoscopy examination abnormal conditions of external ear canal was found in 13.65% of cases mostly impacted ceruman (13.3%). Abnormal conditions of external ear canal was more prevalent in girls than boys and the difference was statistically meaningful in the right (P V=0 .012) and left (PV=0.043) ear. Abnormal tympanic membrane was seen in 6.75% of cases mostly retraction (295%).
2- Impedance Audiometry: 11.05% abnormal tympanograms were observed, mostly type C (4.1%).
3- Pure Tone Audiometry: An overall 9.7% hearing loss was found in this population including 3.5% bilateral and
6.2% unilateral hearing loss. 4.15% of population suffered from SNHL observed mostly in boys and conductive. Hearing loss mostly in girls and the difference was statistically meaning in the left ear (PV=0.03).25.8% of cases were in need of medical care and surgery and six of them (l.e 0.6%) were in need of rehabilitation services.Family background showed on effects on the hearing disorders.Only 11. 4% of parents, 13.4% of teachers and 14.4% of afflicted students were aware of the problem.

Objectives: determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, Impedance Audiometiy and questionnaires.
Methods and Materials:This study was carried out in a cross - sectional descriptive survey - on 1200 students (600 girls and 600 boys) among the student of primary school of Neishabbor, academic year 1376-77
Results:1- Otoscopy examination abnormal conditions of external ear canal was found in 14.1% of cases mostly impacted ceruman (13.6%) Abnormal conditions of tympanic membrane (0.4%) and foreign body 0.16%. Abnormal conditions of external ear canal was statistically unmeaningful. (P V=0 .8)
2- Impedance Audiometiy: 5. 75% Abnormal tympanograms were observed, mostly type C (3.15%)
3- Pure Tone Audiometry: An overall 5.5% hearing loss was found in this population including 3% bilateral and 1.25% unilateral hearing loss. Only conductive hearing loss was found in this population (2.7% in right ear and 3.5% in left ear), PV=0.9.Hearing loss observed mostly in girls but the difference was slight.Family background showed no effects on the hearing disorders.9.8% of cases were in need of medical care and 0.3% were in need of rehabilitation services.Only 28.8% of parents, 36.3% of teachers and 40.9% of afflicted students were aware of the problem.

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.

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.

Objective: Infants hearing screening as one of the best methods of identification and hence early intervention to prevent side effects and appropriate rehabilitation if necessary.
Methods and Materials: 175 0-7 day infants were tested in two groups (112 normal history and 63 high risked) with a dumb (for low frequencies)and receiver (for high Frequencies) at 90-95 dB SPL in three hospitals. The acceptable responses were auropalpebral reflex (APR) , startle and stop of movements.
Results: Of the first group 51% showed APR, 10% startle, 22 % Both and 17% no response. Of the second group 47% showed APR, 24% startle, 11% both reflexes and 18% no response.
Conclusion: 14 cases (8 girls and 6 boys) out of 175 infnats showed no response.

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.

Method & Material: This study was performed on 36 normal-hearing subjects aged 18-25 years for survey of temporary threshold shift (TTS) by transient evoked otoacoustic emissions. Finding: Noise can affect the pure-tone thresholds and (TEOAEs) amplitudes. When cochlea affected by noise, evaluating TEOAE is more suitable than pure-tone audiometry. Because of this test, is objective an unaffected by attention and alertness and can be evaluated in difficult to test subject and also have high carefulness and can be performed in a quiet, but not sound-proof room.

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.

Objective: The purpose of study was identify hearing loss in thalassemic patients with history of Desferrioxamine (DFO) therapy. This study was carried out in a cross-sectional descriptive survey on 195 thalassemic patients (3-30 years old) in Gazvin Thalassemia center and Tehran pediatrics&apos medical center.
Methods: The patients underwent routine otolaryngologic history and physical examination, along with standard pure-tone audiometry.
Results: Hearing loss was present in 43.1% of patients. 16% of patients had conductive hearing loss and 4.6% of patient had sensory neural hearing loss. 22.5% of thalassemic patients had high-frequency sensory neural hearing loss and more importantly, high-frequency hearing loss attributable to Desferrioxamine ototoxicity was present in 12% of patients. Furthermore, these evaluations showed that there is a significant relationship between hearing loss and DFO usage and hearing loss too. There is no significant relationship between hearing loss and ferritin level between hearing loss and age of DFO usage too.
Conclusion: Management of these patients requires proper dosing of Desferrioxamine, along with regular otolaryngolgic and audiometric follow-up in order to prevent the effect of ototoxicity of desferal.

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.

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.

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.

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.

Background and Aim: High frequency audiometry (HFA) provides a valuable tool and optimal index for distinguishing and monitoring many pathologies of the ear. The purpose of this study was to measure the reliability of HFA threshold in children.
Materials and Methods : In this cross-sectional study , 100 normal-hearing children, of 7 to 13 years old, including 50 boys and 50 girls were examined with a Belton 2000 audiometer and Sennheiser HD 250 earphones in Pediatric Clinic  of Audiology Department, Faculty of Rehabilitation of Tehran University of Medical Sciences.
Results: The threshold differences between right and left ears in two test sessions, were not significantly different except for 14 KHz. HFA threshold in two test sessions showed no significant difference in all frequencies between girls and boys but 16 and 20 KHz in right ear and 10 KHz in left ear.
Conclusion : The test-retest thresholds for iudividual ears showed ±0-10 dB SPL for difference at least  in 99.74 % of ears at all frequencies that is clinically reliable and acceptable.