Clinical application of tympanometry in the topic diagnosis of hearing loss A study from Bulgaria

The study aims to demonstrate the clinical implementation and usefulness of tympanometry in diagnosis of hearing loss, focusing on the localization of the pathological process. The results elucidate the clinical diagnosis, contributing to build an adequate treatment and facilitating the evaluation of effectiveness in the follow-up period. The clinical study was conducted in the Audiology Sector of the Department of Otorhinolaryngology, Medical University Sofia, for a period of two years, comprising 714 ears of 379 patients. The patients were divided in 2 groups: 1. Pediatric aged between two months and 18 years 336 ears (47%), and 2. Adult from 18 years old up to the age of 87 378 ears (53%). The following equipment was used impedancemeters (Siemens SD 30, Interacoustics AT 235 H); portable tympanometer (Welch-Allyn). For establishment of hearing impairment additional methods have been used tonal audiometry, OAE, evoked response audiometry. The results were assessed as: conductive, sensoneural and combined hearing loss. The results were interpreted according to the following criteria: admittance, Tympanometric Peak Pressure, peak amplitude, the volume of the ear canal, compliance (ml/cc), peak pressure (daPa), and the change in gradients (%). Patients with conductive hearing loss were divided in 4 groups: a) middle ear effusion 179 children and 26 adults; b) Eustachian tube dysfunction 32 children and 34 adults; c) ossicular chain adhesions 18 children and 85 adults; d) tympanic membrane perforations 48 children and 27 adults. Based on the clinical results from the current study we could estimate the tympanometry as an objective and informative method for daily diagnosis of hearing loss.