What does a flat tympanogram typically indicate?

A flat tympanogram typically indicates the presence of Eustachian tube dysfunction. This type of tympanogram shows minimal movement of the tympanic membrane (eardrum), which suggests that there is a problem in the middle ear space. In a healthy middle ear, changes in air pressure can cause the tympanic membrane to move in and out, leading to a more varied tympanogram.

When the Eustachian tube is not functioning properly, it fails to equalize the pressure between the middle ear and the external environment, which can result in fluid accumulation and reduced mobility of the ear drum. This flat response is often seen in cases of negative middle ear pressure or fluid in the middle ear, both of which are associated with Eustachian tube dysfunction.

Other options may reflect conditions that influence middle ear status but would typically present with different tympanometric results. For example, normal middle ear function would show a peak on the tympanogram, while excessive earwax buildup or inner ear pathology might suggest different types of tympanograms or findings.