4: Real-Ear Measurements
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4.2.4 Placing the Probe Tube
To ensure the proper insertion depth of the probe tube into the ear canal, the
following marking procedure is necessary. After some practice, the procedure is easy.
1. Place an unattached probe tube on a flat surface along with the client’s earmold
or shell as shown in Figure 4.2.4A so that the tube rests along the bottom of the
canal part of the earmold, with the tube extending at least 5 mm past the canal
opening.
2. Mark the probe tube with a marking pen where it meets the outside surface of
the earmold.
3. Place the wedge-style earhook on the client’s ear.
4. Attach the reference microphone, facing forward, on the wedge of the earhook,
directly above the ear to be tested.
5. Attach the probe tube to the body of the probe microphone and then attach the
probe microphone to the round Velcro pad on the ear hanger.
6. Insert the probe tube into the client’s ear so that the mark is at the location
where the bottom of the outer surface of the earmold would be. See Figure 4.2B.
Hints: To help keep the probe tube in place, position the tube so that it runs through
the tragal notch, resting against the lower edge of the tragus (Figure 4.2.4B) If
necessary, reposition the body of the probe microphone lower on the Velcro button
of the ear hanger. If desired, use surgical tape to hold the tube in position.
Reference
microphone
Wedge-style
earhook
Probe
microphone
Probe
tube
Figure 4.2.4A
Figure 4.2.4B
Figure 4.2.4C
Mark the probe tube.
Place the microphones.
Insert the hearing aid.
