Estimated volume of air in front of the probe (equivalent ear canal volume [Vea])

This volume is displayed on the tympanogram printout. The range of normal is age-dependent.

Maximum compliance (mobility) of the middle ear system (static admittance)

The mobility of the tympanic membrane is maximal when air pressures are equal on both sides of it.11 Static admittance is the greatest amount of acoustic energy absorbed by the middle ear system (the vertical peak of the tympanogram tracing).

Pressure at which the middle ear system has the greatest absorption of sound energy, or mobility (tympanometric peak pressure)

This value is an estimation of middle ear pressure and normally is around zero. It is the point on the horizontal axis (pressure axis) where the compliance is highest (the vertical peak of the tympanogram).

Width of the tympanogram curve

The tympanometer can be connected to a printer that will generate a tympanogram tracing and calculate these parameters, indicating whether they are outside the normal limits for adults or children. Optimal results are obtained if the physician and patient minimize movement during the test. A variation that may be more sensitive but more complicated to perform and interpret than standard tympanometry employs a sweep of tones with varying frequency (multiple-frequency tympanometry).26–28