Though various effects can change amplitude or produce fades, visual fade and gain controls make the task quick and intuitive. As you drag these controls in the Editor panel, a preview helps you precisely adjust audio.

A. Fade controls B. Gain control (heads-up display)
Note:
To quickly fade selected audio, choose Favorites > Fade In or Fade Out.
Adobe Audition offers three types of visual fades:
Linear fades produce an even volume change that works well for much material. If this fade sounds too abrupt, however, try one of the other options.
Logarithmic fades smoothly change volume slowly and then rapidly, or vice versa.
Cosine fades are shaped like an S-curve, changing volume slowly at first, rapidly through the bulk of the fade, and slowly at the finish.
Note:
In the Waveform Editor, fades permanently change audio data. To apply fades you can readjust in the Multitrack Editor, see Fade or crossfade clips in a track.

A. Linear B. Logarithmic C. Cosine
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In the upper left or right of the waveform, drag the Fade In
or Fade Out
handle inward, and do any of the following:
For a linear fade, drag perfectly horizontally.
For a logarithmic fade, drag up or down.
For a cosine (S-curve) fade, hold down Ctrl (Windows) or Command (Mac OS).
Note:
To create cosine fades by default and hold the keys above to create linear or logarithmic fades, change the Default Fade setting in the General preferences.