Frye FONIX FP40D User Manual

Page 86

Advertising
background image

78

FONIX FP40 Portable Hearing Aid Analyzer

5.1.2.3 To insert the probe tube
There are several different methods used for properly inserting the probe tube. Here are two easy
methods.

Method 1

1. Place an unattached probe tube on a flat surface along with the client’s earmold or shell.

2. Place or hold the ear mold next to the probe tube, so that the tube rests along the bottom

of the canal part of the earmold, with the tube
extending at least 5 mm (1/5 inch) past the canal
opening. If there is a large vent, you can slide the
tube down the vent until it protrudes at least 5
mm past the canal opening.

3. Mark the probe tube where it meets the outside

surface of the earmold with a marking pen. See
Figure 5.1.2.3A.

4. Attach the probe tube to the body of the probe

microphone.

5. Attach the probe microphone to the round Velco

pad on the earhook.

6. Insert the probe tube (without the earmold or

aid) into the client’s ear so that the mark is at the
location where the bottom of the outer surface of
the earmold will be, once the earmold is in place.
See Figure 5.1.2.2

Method 2

This method is easiest if you have the Composite Option. It uses the fact that there is a dip in gain
caused by a standing wave created by the 6 kHz frequency reflecting off the eardrum.

1. Press F5 to enter Probe Mode.

2. Press F7 to select the Composite signal. You may have to press the button repeatedly.

3. Press START/STOP to start a measurement.

4. Insert the probe tube carefully, looking at the composite measurement. At some point, there

will be a large dip at 6 kHz caused by the standing wave inside the ear. Keep inserting the
probe tube until that dip goes away. See Figure 5.1.2.3B.

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. 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.

Figure 5.1.2.3A—Marking the probe

tube

Advertising
This manual is related to the following products: