What is indicated by a flat line on a tympanometry graph?

A flat line on a tympanometry graph indicates abnormal tympanic membrane movement. This result typically suggests that there is a problem with the middle ear that prevents the tympanic membrane from moving normally in response to changes in air pressure. Several conditions can cause this abnormality, such as fluid buildup in the middle ear (like otitis media), a perforated tympanic membrane, or Eustachian tube dysfunction.

In contrast, a normal tympanometry graph would show a peak, indicating proper movement of the tympanic membrane, which is expected in individuals with healthy middle ear function. Options related to lung airflow or allergies do not directly connect to the function of the tympanic membrane or the results of tympanometry, which focuses specifically on the condition of the middle ear and its ability to transmit sound effectively. Therefore, a flat line is a clear indicator of an underlying ear issue that requires further investigation.