Welch Allyn TM 262 Auto Tymp - User Manual - Manual (Page 63)

Revised 4/11/08 4-5
Test Results
Acoustic reflex
Normal
For screening purposes, an ipsilateral reflex measured at any one of the three levels available
per frequency can be considered normal. Obviously, the lowest values are desired. However,
without knowing the hearing threshold level of the individual per frequency, it is difficult to
make a more definite statement. Generally speaking, the reflex is reported to occur at between
70 and 90 dB HL above the hearing threshold in normals. Remember that these values apply to
reflex threshold measurements and that your instrument does not permit reflex threshold
measurements due to the use of a hand-held probe. The presence of a reflex in the absence of a
compliance peak suggests that the tympanometric results should be considered invalid and the
test repeated. This is true because if there is no compliance measured during tympanometry, it
is not possible to measure any stiffening affect during the reflex stimulus presentation.
Abnormal
If a pressure leak occurs during the reflex testing and the pressure system is unable to correct
for this leak, the reflex test sequence is aborted. When this occurs, the test results are assigned
the letters NT (Not Tested).
If no response is obtained at the third and final stimulus level, the instrument will indicate this
with the letters NR or No. More detailed testing at the frequency where this occurred is
required to determine the reason for the no response.
Audiometry
Normal
A normal response from a child should be at or below 20 dB HL. A normal response from an
adult will be somewhat higher at or below 25 dB HL. Remember that these normal values
assume a quiet environment during testing.
Abnormal
In children, a failure to respond to a 20 dB HL (or lower) stimulus presentation during a retest
performed four to six weeks after the initial test would indicate the need for more extensive
diagnostic testing to determine the cause.
In adults, a failure to respond at or below 25 dB HL when the room noise levels are low
indicates the need for more evaluation. However, the age and employment history of the
individual must also be considered.