Maico MI 24, Operating Instructions Manual

Page: 27 / 53

Operating Instructions MI 24, MI 24h
25
6.5 Preparing the contralateral measurement (optional)
Switch on the contralateral reflex
measurement by pressing the
Reflex
key (the word Contra must appear on
the right top of the LCD). Here the
highest fixed level is 110 dB
HL
(with
TDH 39 contra phone only).
The contralateral measurement
produces more reliable results because
the receiver emitting the test signal
and
the probe measuring the
compliance are separated.
If you are using an insert phone for
contalateral measurement, put an
appropriate ear tip on the insert phone
and insert it in the contralateral ear.
Continue now as described previously
for the ipsilateral measurement.
6.6 How to interpret the reflex display
After having carried out a measurement
you can read the recorded values on
the LCD.
In addition to the tympanogram shown
on the left side and the values shown
on the right, the results of the reflex
measurement appear in the lower part
of the display. In the four boxes marked
1 to 4 the Stapedius response is shown
graphically. Below each box the test
level, the test frequency and the type of
the test (
I =ipsi, C =contralateral) are
shown. The test result is also shown as
Pass or Fail . In (Figure 22), for 500 Hz a
Stapedius reflex was registered at 100
dB
HL
and for 4 kHz at 95 dB
HL
. If no
reflex threshold is registered, Fail
appears below the frequency.
Correct interpretation of the reflex results should be made in conjunction with the
tympanogram, the graphic reflex display and other audiometric data.
Status
READY
Ear Volume
Compliance
Pressure
Gradient
Impedance Contra Right
ml
3
2
1
0
-600 -300 300 daPa
1
100
500 Hz C
4
95
4000 Hz C
3
100
2000 Hz C
2
100
1000 Hz C
AUTO dB Scale
0.94 ml
0.81 ml
- 37 daPa
32 daPa
PASS PASS PASS PASS
Figure 21
Example of a normal tympanogram
with contralateral reflex results
Status
READY
Ear Volume
Compliance
Pressure
Gradient
Impedance Ipsi Right
ml
3
2
1
0
-600 -300 300 daPa
1
100
500 Hz I
4
95
4000 Hz I
3
100
2000 Hz I
2
100
1000 Hz I
AUTO dB Scale
0.94 ml
0.81 ml
- 37 daPa
32 daPa
PASS PASS PASS PASS
Figure 22
Example of a normal tympanogram
with ipsilateral reflex results