Interpreting 226-hz tympanogram results, Normal middle ear low admittance tympanograms, Normal middle ear – Welch Allyn MicroTymp 3 portable tympanometric instrument - User Manual User Manual
Page 33: Low admittance tympanograms, Right ear, Left ear
Directions for use
Interpreting test results
33
Interpreting 226-Hz tympanogram results
Normal middle ear
A tympanogram with normal Peak Ya, gradient (width), and tympanometric peak pressure
appears below.
Low admittance tympanograms
Tympanogram with normal Peak Ya and abnormal gradient (width)
Conditions which cause tympanograms with normal height and increased width:
•
Otitis media with effusion
•
Tympanosclerosis
-400
-200
0
200
2
0.5
0
1.0
1
1.5
PRESSURE - daPa
Ya - mmho
Vea
+200
RIGHT EAR
R
Note
Low Peak Ya of the middle ear is produced by space-occupying lesions in various
ways. A lesion that displaces air in the middle ear space causes low admittance
by reducing the middle ear volume. The lesion also may interfere with the
vibration of the ossicular chain, contributing to the low admittance. If the lesion is
in contact with the eardrum, low admittance is a result of interference with
eardrum vibration.
-400
-200
0
200
2
0.5
0
1.0
1
1.5
PRESSURE - daPa
Ya - mmho
Vea
+200
LEFT EAR
L