As normal middle ear resonance is between 8 Hz, 226 Hz tympanogram is sensitive to changes in stiffness characteristics of the middle ear and may fail to distinguish pathologies that alter the mass of the middle ear. Most commonly used probe tone frequency for tympanometry is 226 Hz. It assesses the mobility of the tympanic membrane as a function of air pressure in ear canal. Tympanometry is used extensively for assessing the middle ear functions. These findings highlight the efficiency of 1000 Hz probe tone in detecting mass dominant middle ear pathology.
They are in accordance with the concept that subtle changes in the middle ear which cannot be detected by 226 Hz tympanogram can be identified using 1000 Hz multicomponent tympanogram. It was observed that 53.84% of the ears could be identified as having middle ear pathology using 226 Hz probe tone whereas the percentage of correct identification increased to 94.87% when 1000 Hz probe tone was used. Results revealed normal tympanogram for both the probe tones for all the participants of Group I. Single component tympanometry for 226 Hz probe tone and Susceptancec and Conductance tympanograms for 1000 Hz probe tone was carried out on all the participants. Data were collected from 20 ears of 10 participants with no history of middle ear pathology (Group I) and 39 ears of 26 participants (Group II) with history of middle ear infection or ear-pain or blocking sensation. The present study was undertaken to investigate the efficacy of multicomponent tympanometry for 1000 Hz probe tone in detecting middle ear pathology.
Multi component tympanometry is not widely used in clinics due lack of evidence supporting its usefulness.
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