What does a Type C tympanogram suggest about the middle ear pressure?

A Type C tympanogram indicates that there is negative pressure in the middle ear. This negative pressure is typically a result of Eustachian tube dysfunction, which can occur when the tube does not open properly to equalize pressure between the middle ear and the outside environment. In a healthy middle ear, the pressure should be at atmospheric levels (normal pressure), but when the Eustachian tube is not functioning well, negative pressure can develop, leading to potential discomfort or hearing issues.

In this scenario, a Type C tympanogram is characterized by a peak that occurs at a point of negative pressure on the tympanogram graph. This peak demonstrates that the compliance of the tympanic membrane is optimal at the point of negative pressure, indicating a shift from the normal pressure condition. It does not indicate the presence of fluid or excessive positive pressure, which would be shown by different tympanogram types. Thus, the designation of Type C specifically corresponds to the presence of negative pressure in the middle ear.