Timpaniomeetria

Timpaniomeetria, or tympanometry, is a diagnostic procedure used to assess the function of the middle ear by measuring the movement of the tympanic membrane in response to changes in air pressure within the ear canal. The test uses a tympanometer, which places a small probe in the ear and delivers a calibrated tone while varying the air pressure. A microphone detects the reflected sound to quantify how much the tympanic membrane moves at each pressure level. In adults, a 226 Hz probe tone is commonly used; in infants, a higher frequency such as 1000 Hz may be preferred to improve sensitivity.

The result is a tympanogram, a graph of tympanic membrane mobility (compliance) as a function of ear canal pressure. The peak of the curve indicates the point of maximum mobility and the surrounding pressure value reflects eustachian tube status. Normal tympanograms are typically classified as Type A, showing normal mobility around atmospheric pressure. Variants include Type Ad (hypercompliant membrane), Type As (reduced compliance), Type B (no mobility, often indicating effusion or perforation), and Type C (negative pressure suggesting eustachian tube dysfunction).

Timpaniomeetria is commonly used to evaluate suspected middle-ear problems such as otitis media with effusion, acute otitis media, eustachian tube dysfunction, perforated tympanic membrane, and barotrauma. It is frequently employed in pediatric audiology and preoperative assessments, and may be used as part of newborn hearing screening in some programs.

Limitations include reduced utility in the presence of active ear canal blockage (cerumen) or significant conductive hearing loss, and the need for cooperation and proper probe seal. Results should be interpreted alongside clinical findings and audiometry.