Frye FONIX 7000 - Manual (Page 146)

138
FONIX 7000 Hearing Aid Analyzer
6.3.4 Entering Bone Data
The NAL-NL1 target uses bone data in its calculations. If the patient’s bone
thresholds are not entered, it will assume average values. No other fitting rules
use the bone data. To enter this data:
1. Press [MENU] in the Audiogram Entry screen to open the local menu.
2. Set the FITTING RULE to NAL-NL1 using the arrow keys.
3. Press [EXIT] to exit the local menu.
4. Press [F2] repeatedly until BONE is selected.
5. Use the arrow keys to enter the bone values into the appropriate column of
data.
6.3.5 Performing an RECD measurement
The real-ear to coupler difference (RECD) is the acoustical difference between a
2-cc coupler and the real-ear occluded response of an individual. It involves a
coupler measurement and a real-ear measurement. Both measurements are usu-
ally performed with an insert earphone as the transducer.
It’s also possible to use a linear hearing aid, instead of an insert earphone, to
perform the RECD test. In this case, you would use the same hearing aid, set
with identical volume control and/or other settings, for both the coupler and
real-ear portions of the test. The DSL Method does NOT recommend using a
hearing aid as the RECD transducer.
Coupler Measurement
The coupler part of the RECD is performed when you “calibrate” the insert
earphone used in the measurement. When this calibration is performed, the
coupler measurement is stored into permanent memory. This saves a lot of time
because, after the coupler measurement is made once, you will only have to per-
form the real-ear part of the RECD for each patient. If you change the transducer
or calibrate your microphones, make sure to perform the coupler measurement
again.
The following instructions assume you are using an ER3 insert earphone for
performing the RECD measurement. The 7000 Test System will eventually sup-
port an RECD method using a linear hearing aid, but that feature is not yet
implemented.