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.

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.

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.