Fading regions to reduce artifacts
Audio may have unintended noises, such as hum or hiss, that are masked when audio like narration is playing but are audible when the narration stops. Other unintended noises can also occur, like “p-pops” (a “popping” sound that happens from the sudden burst of air associated with plosive sounds like “b” or “p”), clicks, mouth noises, and so on. Audition has advanced techniques for removing noise and doing audio restoration, but for simple problems, a fade is often all you need.
- Choose File > Open, navigate to the Lesson03 folder, and open the file PPop.wav.
- Zoom in and move the playhead to the start of the file. The keyboard shortcut to do this is Ctrl+left arrow (Command+left arrow). Note the spike at the beginning that corresponds to the “pop.”
- Click the small, square Fade In button in the upper-left corner and drag to the right. You can see the fade attenuating the spike. Dragging the Fade In button up or down alters the fade’s shape (up for convex, down for concave). A concave fade is an ideal choice here, because it gets rid of the most objectionable part of the pop but still leaves in the “p” sound.
- There’s also another, less objectionable pop at 0.20 seconds. Although you could cut this file to the clipboard, create a new file, add a fade-in, and paste it back into place, an easier solution is simply to select the pop sound as a region and use the HUD’s volume control to drop the level by 8 or 9dB.
- Suppose you want to shorten the file to end with “...that can happen” instead of “that can happen when recording.” Zoom in and go to the end of the file. Locate the part that says “when recording,” select it as a region, and then press the Delete key.
- However, now “happen”doesn’t end elegantly; there’s an audible artifact at the end. You’ll use the Fade Out button to reduce this.
- Click the Fade Out button and drag left to 2.8 seconds. Then drag down to about -30 and release the mouse button to make the fade “stick.”
- Play the file to hear that the artifact at the end is gone.