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Tutorial: Fixing Flawed Audio in Adobe Creative Cloud

The three audio problem areas I'll tackle in this entry-level tutorial are as follows: removing transient noises like pops and clicks, cleaning up pervasive background noises, punching up weak-sounding audio.

Noise Reduction in Audition

Let’s start by removing the background noise. For perspective, if you’re working with dozens of audio files and are in a hurry, you may prefer to work with the Reduce Noise Function in Premiere Pro’s Essential Sound panel, which deploys Premiere Pro’s Adaptive Noise Reduction filter. On the other hand, if you’re seeking to lovingly optimize the quality of a single clip, you’ll probably find Audition’s Noise Reduction Process more effective.

Here’s why: At a high level, think of noise reduction as a continuum between noise and distortion. If you remove too much noise, you distort the audio, which may be more noticeable than the background noise. So, when removing noise, you’re attempting to find the optimal balance between noise reduction and distortion creation. As you’ll see, Audition has a fabulous toolset for finding this sweet spot.

Noise reduction in Audition is a two-step process: First, you identify the noise, then you configure the noise reduction filter. I show how to identify the noise in Figure 3. You drag and select a region on the waveform containing only noise and then choose Effects > Noise Reduction/Restoration > Capture Noise Print. When you select a region, preview to make sure that you’re capturing only the background noise to be removed, and not other sounds. When you’ve identified the ideal sample, load the dialog shown in Figure 4 (below) by clicking Effects > Noise Reduction/Restoration > Noise Reduction (process).

Figure 4. Customizing the Audition Noise Reduction filter

I won’t go into the Advanced controls accessed via the Advanced option on the bottom, leaving only two controls to adjust: Noise Reduction, which defines the noise you’re going to remove; and Reduce By, which controls the decibel reduction to that noise. To configure these settings, you have some outstanding preview tools, which is the special sauce that Audition delivers that Premiere Pro doesn’t.

To state the obvious, you will work most effectively in a quiet room with headphones. In addition, consider the purpose of the operation. Your goal isn’t to remove every last bit of background noise from the audio, particularly if that causes distortion, or even if it causes a mismatch between the audio and video. For example, my video was shot in a large ballroom, where some measure of ambient sound is expected. So my goal is to remove as much background noise as possible without introducing distortion or causing a mismatch between what the viewers are hearing and what they’re seeing.

After capturing the noise print, my process is to enable the Output Noise Only toggle (as shown), which plays the audio being removed by the filter, not the residual. Click the Select Entire File first to hear the entire file, rather than just the noise you selected in the previous step. Or, make another shorter selection directly in the Audition waveform to use during the preview.

While previewing with Output Noise Only, drag the Noise Reduction slider to the left and right. Typically, the further you drag to the right, the more voice you’ll hear in the removed audio. The more voice you hear, the more likely you are to introduce distortion into the audio. On the extreme left, however, you limit the noise that’s being removed, which is the object of the exercise. If possible, find a spot where you hear only noise in the preview, and none of the voice, which is the optimal position.

If you hear a voice in all settings, deselect the Output Noise Only toggle, and drag the Noise Reduction slider to find the best balance between noise reduction and distortion. To help gauge your selection, you can toggle the effect on and off with the control on the bottom left of the dialog, which is incredibly useful. Then press Apply to apply the filter. In the waveform in Audition, you should see much of the bushiness around the centerline disappear.

Probably one in 10 times you use this effect, you’ll press Apply and see a flatline on the audio waveform. This means that you forgot to deselect Output Noise Only, so Audition saved only the noise (it’s a feature). Just click Undo, run the filter again, and remember to deselect Output Noise Only. If you’re working with multiple files from the same recording, you can save your settings as a preset using the controls at the top of the dialog.

The New DeReverb Dialog

As mentioned, there was a slight amount of reverb in the audio, which I sought to address with Audition’s new DeReverb tool (Effects > Noise Reduction/Restoration > DeReverb). Note that this is a brand-new filter (Figure 5, below) available only in Audition CC 2019, so if you’re not seeing it, make sure you’re running Audition CC 2019.

Figure 5. The new DeReverb filter in Audition 2019

Operationally, there are three controls to consider. First is the Amount slider, which controls how much reverb you remove from the audio. Second is the processing focus, or the frequencies you want to adjust, which you control via the icons above the Amount slider. Third is the Auto Gain slider, which I didn’t check because I planned to adjust audio volume in the next step.

This is the first time I used the filter. What proved most useful for me was to select a short segment of dialogue in the waveform to loop-through. Then, with the strength set at 50, I started previewing. I switched the processing focus from All to Low, to Mid, to High and Low, and finally to the higher setting, which allowed me to remove the reverb without impacting the vibrancy of the residual audio. Though subtle in my clip because the reverb was minimal, this could be a killer curative effect when reverb is a significant problem. When you’ve reached the optimal setting, click Apply to apply the effect.

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