Normal Tympanogram

Normal tympanogram. Two subsequent tympanograms from the same healthy ear of a child. The shape of the curve (here type A) is the essential feature, not the height of the peak. 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 Tympanogram Types C and A).

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