74 Normalizing Audio in Premiere Pro and Audition

#74 Normalizing Audio in Premiere Pro and Audition

Typically, you normalize audio volume so your entire production will have similar levels and your viewers won't have to adjust the volume from scene to scene. Technically, however, normalization increases the amplitude of the audio to a target level, usually 100%, which is maximum volume available without distortion.

Audition Will Drive You Crazy if You Don't Know This One

Got your attention, didn't I? Audition grays out most effect controls, including Normalization, when you pause rather than stop audio playback. To make the controls active, click the black "Stop" button in the upper-left corner of the Transport panel (grayed out in Figure 73).

What's critical to realize is that normalization affects the entire file equally. So if you have a file (or region in a file) with loud segments, but also with low segments, normalizing the entire file will probably not increase the volume of the low points.

Still Not Loud Enough?

If normalizing the low-volume regions doesn't boost volumes to the required level, try increasing the volume using the Amplify effect (Effects > Amplitude > Amplify). As long as the waveform doesn't flatten out at the top or exceed the 0 dB levels, you shouldn't introduce any distortion into the audio.

Consider the two regions defined in Figure 74a. Region A has consistently low volume, while Region B has both high and low points. If you normalized Region A, you would increase the volume of the low points to much higher levels. However, if you normalized Region B, Audition might even reduce the volume a bit, making the low-volume portions even harder to hear.

Figure 74a. Normalizing Region A will produce a different result from normalizing region B. This is a stereo file, but I'm showing only the upper track for clarity.

Audio Getting Noisy?

Boosting volume through the Normalization or Amplify effects invariably seems to introduce noise into the audio. If you're experiencing this problem, check out #75.

If Figure 74a was a piece that was supposed to have high and low regions (say, the 1812 Overture), normalizing Region B, or even the entire song, would produce the desired resulta piece rendered at maximum volume with the desired highs and lows without distortion. In this case, you could safely use Premiere Pro's Normalization tool, accessed by right-clicking the Audio clip and choosing Clip Gain from the pop-up menu that appears, and then clicking the Normalize button (Figure 74b).

Figure 74b. You can normalize in Premiere Pro with this dialog box.

On the other hand, if Figure 74a was a song (or wedding ceremony) with loud applause at the end, normalizing the entire file wouldn't increase the volume in the lower regions, which might be the bride or groom softly stating their vows. In these instances, normalize in Audition to target specific portions of your audio clip.

Need to Normalize Multiple Files?

If you have multiple files to normalize, load them into Audition, select the files in the Files panel, right-click, and choose Edit Group Waveform Normalize from the pop-up menu that appears. Audition will analyze the files and normalize their respective volumes.

To increase low-volume regions in Audition, do the following:

1.	In the Display area, click and drag in the waveform to select the quiet regions.
2.	Choose Effects > Amplitude > Normalize (process).
3.	If the default parameters shown in Figure 74c suit your needs (usually, they will), click OK to apply the effect. Figure 74c. Audition's Normalize dialog box. Note that the audio has already been normalized using the selected region, with substantially increased volume compared to Figure 74a.

Note that the selected region in the audio file in Figure 74c has already been normalized, and if you compare the volume to Figure 74a, you'll see that it has been substantially increased by the normalization effect.

Working Through a Long Audio File?

When working through a long audio file (say 2 minutes or more), you might find it helpful to use markers to break the file into regions and then edit them individually. To set a marker, move the current-time indicator to the target location, right-click, and choose Add to Marker List. You can divide the regions by duration, or use natural breaks like songs or scenes.