Which type of tympanogram indicates a normal middle ear function?

A Type A tympanogram indicates normal middle ear function. This test measures how well sound waves travel through the middle ear, and a Type A waveform shows that the tympanic membrane (eardrum) is moving freely and that there are no fluid or pressure issues in the middle ear.

Type A tympanograms exhibit a peak at normal pressure (zero daPa) and indicate that the middle ear space is filled with air. This suggests that the ossicles (the small bones in the middle ear) are functioning correctly, and there are no obstructions or infections present. When evaluating hearing disorders, understanding the implications of tympanometric findings is crucial, as they can guide further diagnostic and therapeutic decisions.

In contrast, Type B tympanograms suggest the presence of fluid in the middle ear or a perforated eardrum, while Type C tympanograms indicate negative pressure, often associated with eustachian tube dysfunction. Type As tympanograms point to reduced mobility of the tympanic membrane, implying possible stiffness in the middle ear system, often linked to otosclerosis.