FONIX® FP35 Touch - Frye Electronics

Real-Ear Measurements 133
Follow the directions in Section 5.3.6 to obtain an REDD using an insert earphone.
Follow the directions in Section 5.3.8 to obtain an REDD using the
sound field speaker. After performing the measurements, press [F5] to toggle the
view to show REDD.
When TDH is the selection for the ASSESSMENT field, the REDD cannot be
measured automatically with the FP35 analyzer. Instead, the average values will
be used, or measured values can be entered manually.
To measure the REDD transform with the FP35 analyzer and a separate audiometer
(the Composite option is required):
1. Enter the Aided Gain measurement screen by using the [NEXT] and [BACK]
keys from the Audiogram Entry screen.
2. Press [MENU] and use the arrow keys to set the REF MIC to OFF. Use [EXIT]
to return to the measurement screen.
3. Use [F4] to set the source type to COMP. This will put the analyzer in spectrum
analysis mode.
4. Use [] repeatedly to turn the source OFF.
5. Insert the probe tube connected to the probe microphone into the client’s
ear, preferably within 4 mm of the eardrum. Use an otoscope for assistance.
We recommend using a bit of surgical tape to affix the probe tube in place at
the helix.
6. Place the TDH headphones on the client.
7. Press [START/STOP] to begin the spectrum analysis measurement.
8. Deliver 70 dB HL from the audiometer, and record the RMS OUT value as
measured by the FP35 analyzer for each audiometric frequency. This value
is the eardrum SPL.
9. Subtract 70 dB from each SPL value to get the custom REDD.
10. Press [START/STOP] to end the measurement when finished.
11. Use [NEXT] repeatedly to enter the Audiogram Entry screen.
12. Use [F2] repeatedly to select RECD or REDD. If RECD is shown, use [F5] to
select SHOW REDD. An REDD column will appear on the screen to the right
of the HTL, UCL, and TARG columns.
13. Use the arrow keys to enter the measured REDD values that you obtained in
step 9.
5.3.8 Measuring the Unaided measurement
If you used a sound field speaker to take your audiometric measurements, you
should use an REUR (real-ear unaided response) as the HL to SPL transform and
for the generation of targets.