Specifications

Chapter 69: DINR 343
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 Learn to create a preliminary noise sig-
nature.
4 Click Fit to fit a Contour Line to it.
5 In BNR’s Spectral Graph, Control-drag (Win-
dows) or Command-drag (Mac) to make a selec-
tion. Select points where the high-frequency
noise components are most evident. In general,
the flatter areas of the Spectral Graph, are better,
since they represent quieter areas where there is
probably less signal and more noise.
6 Click Auto Fit. DINR computes a generic noise
curve and corresponding Contour Line based on
your selection. If you want to remove the selec-
tion in the Spectral Graph Display, Control-click
(Windows) or Command-click (Mac) once.
7 Follow the steps given in the previous section
removing the noise using the NR Amount slider
and other controls.
8 Since the Contour Line is not based entirely on
noise from your audio file, you may also want to
edit its envelope in order to fine-tune the noise
reduction. See “Editing the Contour Line” on
page 343.
Editing the Contour Line
One of the most effective ways to fine-tune the
effects of broadband noise reduction is to edit
the Contour Line. The Contour Line treats audio
below the line as mostly noise, and audio above
the line as mostly signal. Therefore, the higher
your move the Contour Line upwards, the more
audio is removed.
To maximize noise reduction and minimize sig-
nal loss, the Contour Line should be above any
noise components, but below any signal compo-
nents. To fine-tune the broadband noise reduc-
tion, try moving individual breakpoints at dif-
ferent locations along this line to find out which
segments remove the noise most efficiently. For
more dramatic results, try moving the entire
Contour Line upwards. One drawback of the lat-
ter technique is that it will typically remove a
considerable amount of signal along with the
noise.
Remember that high-frequency noise compo-
nents are typically more evident in the flatter,
lower amplitude areas of the Spectral Graph. Try
editing the Contour Line in these areas first.
To hear the changes you make to the Contour Line
in real time:
1 Select the target audio in Pro Tools’ Edit win-
dow. Make sure the selection is at least a second
or two in length. If the selection is too short, you
won’t be able to loop playback.
2 Select Options > Loop Playback.
3 Begin playback.
Noise components on the Spectral Graph