Background & Objectives: Hearing is perhaps the most important sense in human beings without which communication with the environment would greatly diminish. Chronic perforation of tympanic membrane, ossicular erosion and tympanosclerosis are major causes of hearing diorders. Nevertheless, a conducting hearing loss is the commonest complication of chronic otitis media. Cholesteatoma which is the most dangerous complication of chronic otitis media is treated by surgery. Tympanosclerosis is also one of the most important complications of chronic otitis media, which leads to conductive hearing loss through ossicular fixation. This study is an attempt to determine the effect of different kinds of chronic otitis media on the hearing of the patients.

  Methods: In this survey, 440 patients with chronic otitis media, who were surgically treated in the department of otolaryngology between 1998-1999, were studied in terms of various pathology of middle ear and the resultant level of hearing impairment.

  Results: 37 patients (8.4%) were involved bilaterally with otitis media. The number of operations on the left ear was 10% more than those on the right. The most common pathology recognized in examination was nonprulant perforation of tympanic membrane in 179 cases (40.7%) and the most common pathology recognized in surgery was cholesteatoma in 140 cases (30.2%). From 440 patients, 430 cases had conductive hearing loss and 92 cases (20.9%) had sensorineural hearing loss. Cholesteatoma of middle ear caused the highest proportion of conductive hearing loss and majority of the cases with sensorineural hearing loss (about 30%) whereas tympanosclerosis caused the most severe sensorineural hearing losses.

  Conclusion: The findings indicated that cholesteatoma and tympanosclerosis were the most common causes of both conductive and sensorineural hearing loss with tympanosclerosis as the cause of the most severe sensorineural hearing loss. However granulation tissue is the most common histopathology in patients with chronic otitis media at references and papers.

  Background & Objectives: The hearing organ has a special role in establishing communication among people and their education. Hearing loss causes disorders in communication between human and environment. In growing ages, hearing loss may lead to general educational failure . T his study was conducted in order to determine the relationship between hearing loss and educational failurs.

  Methods: In this case control study 110 failed students in 5^th grade elementary school (case) and 110 other ones (control) were selected by systematic random sampling. Both groups underwent the audiometric tests. The Data were analyzed by EPI 2000 software.

  Results: The results of this study showed that 9.1% of cases and 0.9% of controls needed sonic energy more than 30db in left ear to hear. The difference was significant (P<0.05) whereas there was no significant relationship between hearing loss and educational failure in rigth and left ear in both groups when the sonic energy used is more than 20db.

  Conclusion: The failed students are strongly recommended to be annually examined and evaluted by a specialist and if necessary be treated.

 Background & Objectives: Hearing disorders are the most common causes of pediatric communicative and functional disorders in the united states which result in communicative and learning disorders, educational failure and vast socio-economic problems. It is estimated that the incidence of hearing loss in pediatric population is 2-4% and otitis media, which is the second infectious cause after the ordinary cold, is the most common cause of hearing loss in children. Hearing loss is categorized into two distinct groups, namely conductive and sensorineural, the former being more common among children. Most of the causes for conductive hearing loss can be diagnosed and treated. Hence, majority of hearing loss cases can be prevented by taking appropriate measures. This study was performed to examine the incidence and common causes of hearing loss among school children in Ardabil.

 Methods: This cross-sectional study was performed on 1999 primary school boys and girls (grades 1-5). The data were collected through a questionnaire in the from of autoscopic examinations and Tuning Fork tests. 654 cases were referred to the audiometric and tympana metrics centers for further examinations as well as filling out the questionnaires. 483 (24.2%) students were definitely suffering from hearing loss. The data were analyzed through descriptive statistics and SPSS software.

 Results: In this study, the hearing disorders of male students was more than female ones. The most common causes of conductive hearing loss in both sexes and all 5 grades was cerumen (50.3%) and the second cause was otitis media with effusion (34.6%). The incidence of sensorineural hearing loss was 1.86%. Hearing loss disorders in low socioeconomic households is high (44.1%). There was a meaningful relation between hearing loss disorders and positive family history, educational failure, social class and seasons (p=0.001). Hearing loss disorders are high during the cold seasons (73.90%).

 Conclusion:�Regarding the high prevalence of hearing loss among school children, more extensive and interventional studies as well as wide ranging screening are required.