What does tympanometry measure regarding the middle ear?

Tympanometry is a diagnostic test that evaluates the function of the middle ear by measuring immittance, which refers to the ease with which sound energy flows through the ear system. This test involves varying the air pressure in the ear canal and observing how this affects the movement of the tympanic membrane (eardrum).

The results indicate how well the middle ear is working. Specifically, tympanometry can help identify conditions such as middle ear effusion (fluid), eustachian tube dysfunction, or physical blockage. By assessing how changes in air pressure influence the compliance and stiffness of the middle ear system, tympanometry provides critical information about the health of the middle ear, which can't be directly measured by simply assessing the electrical activity of the cochlea, audiometric thresholds, or transmission efficiency of sound alone.