Which tympanogram configuration is most consistent with otitis media with effusion?

• A. Type A
• B. Type C
• C. Type A-B
• D. Type B

Answer: (D)

Tympanometry tests how well the middle ear membrane moves as air pressure in the ear canal is varied. When the middle ear is filled with fluid, as in otitis media with effusion, the system becomes stiff and the tympanic membrane can’t move well, so there is no distinct peak in the tympanogram across pressures. This results in a flat tracing with little to no mobility, which is the pattern most consistent with middle-ear effusion. In contrast, normal middle ear function shows a peak around zero daPa (normal mobility), and Eustachian tube dysfunction without fluid tends to produce a peak at negative pressure (a negative-deflection). A pattern labeled A-B is not the classic signature of effusion.