66 The DSL/NAL-NL1 Module WinCHAP User’s Manual
6.2.1.2 To use the audiometry table
1. Follow steps 1-4 in the previous section.
2. Select the appropriate column in the Audiometric Information table in the
lower half of the Audiometry window.
3. Enter the amplitude data in the boxes corresponding to the appropriate
frequencies. Use your Enter key to move between fields.
4. Click
Save in the toolbar to save the results.
6.2.2 Entering/Predicting Upper Limit values
The AC Upper Limit values are defined as the client’s upper limits of comfort.
You can choose to have WinCHAP predict these values, based upon the client’s
age and entered thresholds, or you can enter measured values. WinCHAP uses
the DSL method to make these predictions.
Choose between Predicted or
Measured in the Upper Limit box to the right
of the Assessment Data graph. Measured upper limit values are entered in the
same manner as threshold values. See Section 6.2.1.
6.2.3 Entering Bone Conduction values
Bone conduction values are entered in the same manner as threshold values. If
entered, NAL-NL1 uses them in creating measurement targets. DSL does not use
these values.
6.2.4 Performing or Predicting an RECD measurement
The real-ear to coupler difference (RECD) measurement finds the acoustical dif-
ference between a 2-cc coupler and your patient’s ear. The DSL and NAL-NL1
formulas take these differences and create realistic coupler target curves. This is
particularly useful when fitting babies and small children who don’t allow you
to take an actual real-ear measurement.
To predict the RECD based on the patient’s age, selected Predicted in the
RECD
box in the Audiometry window. The predicted RECD (as well as the predicted
REUR and REDD) values are displayed in column format on the bottom half of
the window. DSL and NAL use different predictions for these transforms in their
fitting formulas; the Settings window lets you set which prediction values are
displayed.
To measure the RECD, select
Measured in the RECD box and follow the instruc-
tions in the following sections.
6.2.4.1 To perform the coupler measurement
This section describes how to perform the coupler part of the RECD measure-
ment. The procedure is different for the 6500-CX and FP40 than for the FP35
and 7000 analyzers.
