Real-Ear Measurements 151
Figure 5.7.3.1—Real-Ear static IM distortion test
5.7.3.2 To perform an IM distortion sweep
1. Press [MENU] in the real-ear measurement screen to enter the real-ear
menu.
2. Make sure the REF MIC is OFF. Use the arrow keys to make this selection, if
necessary.
3. Press [NEXT] twice to enter the Custom menu.
4. Select DISTORTION with [
∨, ∧].
5. Use [<, >] to select the harmonics where the IM distortion will be mea-
sured. You can select the 2nd distortion, the 3rd distortion, or TOTAL,
which is all frequencies except the primary and secondary frequencies.
6. Use [
∨, ∧] to select IM FREQ DIFF.
7. Use [<, >] to select the fixed distance between the primary and second-
ary frequencies used in the measurement. You can choose from no distance
(HARM) to 4000 Hz.
8. Press [EXIT] to return to the real-ear measurement screen.
9. Press and hold down [F4]. This will pop up a list of the available selections,
including DIST.
10. Use [
∨, ∧] to select DIST.
11. Press [START/STOP] to make the selection.
12. Use [
∨, ∧] to select the RMS source of the test. Each frequency will have an
amplitude 3 dB less than the RMS source.
