tympanogram

Introduction

A measurement of compliance of the middle ear versus pressure in the external ear canal.

type A (normal)

• tall peak compliance 0.2-2.0 mL of displaced air
• located between +100 to -150 mm H2O

type B (middle ear effusions)

• flat curve, no peak compliance
• lack of tympanic membrane mobility

type C (eustachian tube dysfunction)

• tall compliance peak below the normal range of -150 mm H2O

type D (recovery from acute otitis media)

• short, round compliance peak at variable pressures

Additional terms

• tympanography