IMPEDANCE AUDIOMETRY FOR SCHOOL SCREENING

Using the impedance audiometry, screening of children in the first grade of an elementary school was performed. The children were investigated with pure tone andiometry, impedance audiometry and otoscopy. Screening using pure tone audidnetry was performed at frequencies of 1 and 4 kHz. The hearing threshold more than 20 dB HL was considered pathological in one or both of the frequencies. Screening impedance audiometry was performed with the Madsen impedance bridge ZO 70 (probe tone 220 Hz) and the pressure in the external ear canal was variated from -400 to +200 mmH2O. The screening was performed by tympanometry and measurement of acoustic impedance or static compliance. Out of 145 children, 6 children (4. 1%) with secretory otitis media were discovered by impedance audiometry. Out of these 6 cases, only one was found by pure tone audiometry. Five out of these six children had no subjective symptoms. The results indicated that the screening using impedance audiometry (tympanometry) was more efficient than the screening using pure tone audiometry and otoscopy in the detection of secretory otitis media. In this study, some problems, such as cost of the instrument, time-consumptiveness and high over-referral rate, were pointed out to introduce the impedance audiometry for school screening. However, tympanometry is recommended as a complement of pure tone screening in screening of children.