Specifications

Digidesign Plug-Ins Guide68
6 Adjust the NR amount slider to reduce the
noise by the desired amount. To compare the
audio with and without noise reduction, click
the Bypass button.
7 To fine-tune the effects of the noise reduction,
adjust the Response, Release, and Smoothing
sliders to achieve optimal results.
8 To further increase noise reduction, edit the
Contour Line. The quickest way to do this is to
move the entire Contour Line upwards. In the
Spectral Graph, Command-drag (Macintosh) or
Control-drag (Windows) to select the entire
waveform range. Then click the Move Break-
point Up button. The higher you move the Con-
tour Line above the noise signature, the more
noise is removed. See “Editing the Contour
Line” on page 69.
9 If you feel that some of high end frequencies
of the audio have been lost due to the noise re-
duction process, try using the High-Shelf EQ to
compensate. To do this, click BNR’s HiShelf but-
ton and adjust the frequency and gain sliders
until you are satisfied with the results.
If you are happy with the results of the noise re-
duction, use the Settings and Librarian menus to
save the settings so that you can use them again
in similar sessions.
Performing Noise Reduction on
Audio that Lacks a Noise-Only
Portion
Ideally, audio that you want to perform noise re-
duction on will have a noise-only portion at the
beginning or end of the recording that DINR
can analyze and learn. Unfortunately this is not
always the case, and in many recordings some
amount of signal is always mixed with the
noise. Obviously, analyzing such audio will pro-
duce a noise signature that is based partially on
signal. Luckily, DINR has provisions for cases
such as this, and this is where the Auto Fit fea-
ture comes in.
If your audio file lacks a noise-only portion for
DINR to analyze, you can still obtain reasonable
results by selecting and learning a segment of
audio that has a relatively low amount of signal
and a high amount of noise (as in a quiet pas-
sage). By then selecting a frequency range of the
noise signature and using the Auto Fit function
to generate a generic noise curve, you can re-
compute the Contour Line based on this selec-
tion.
Some editing of the newly generated Contour
Line will probably be necessary to yield opti-
mum results, since it is not based entirely on
noise from your audio file. See “Editing the Con-
tour Line” on page 69.
To generate a Contour Line for audio that lacks a
noise-only portion:
1 In the Edit window, select a segment of audio
with a relatively low amount of signal and a
high amount of noise.
2 Click the Inserts pop-up on the track with the
noise and select BNR. The Broadband Noise Re-
duction window appears.
3 Click the Learn button to create a preliminary
noise signature.
To enable Learn Last Audio mode, Option-
click (Macintosh) or Alt-click (Windows)
the Learn button. This button flashes red
when armed for Learn Last Audio mode.
When you hear the target noise, click
Learn
a second time.