Tympanogram Types C and A

Tympanogram types C and A. Tympanogram types C (left) and A (right). Different tympanogram types:

• type A (normal tympanogram): a clear peak at the ear canal pressure that equals to the tympanic cavity pressure
• type B = a flat, almost horizontal line: middle ear effusion is probable (picture Tympanogram Type B)
• type C: pressure readings below -200 dPa indicate poor ventilation of the middle ear.

Picture: Aino Ruohola / Turku University Hospital/Department of Paediatrics