Welch Allyn MicroTymp 3 portable tympanometric instrument - User Manual - Manual (Page 31)

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Interpreting test results
When measured properly, tympanometric results are accurate and objective but should
be interpreted in the context of the patient’s overall clinical condition.
Tympanograms
Key characteristics of the tympanogram
1 Static Admittance (Peak Ya) is a calculated measure of the compensated static acoustic admittance (height)
of the tympanometric peak reported in acoustic s (mmho). Given appropriate normative values, static
admittance (Peak Ya) is a useful indicator of middle ear disease.
2 Tympanometric Gradient (GR) is a measure of the width of the tympanogram reported in decapascals (daPa)
at 50% of static admittance (Peak Ya) or the tympanometric peak. Given appropriate normative values,
tympanometric gradient is a good indicator of the presence of middle ear effusion.
3 Tympanometric Peak Pressure (TPP) is the location of the tympanometric peak on the pressure axis. TPP is
reported in decapascals (daPa). TPP indicates if there is pressure behind the eardrum but usually does not
indicate middle ear disease.
4 Equivalent Ear Canal Volume (+200 Vea) is an estimate of the volume of air in front of the probe, measured
in cubic centimeters (cc). A high volume suggests an eardrum perforation or patent tympanostomy tube.
Perforations can be present when Vea is normal.