Premiere Pro includes audio plug-ins designed to alter or enhance the properties of audio clips. Most of these effects are available for mono, stereo, and 5.1 clips, and can be applied to clips or tracks. 

Audio effects are combined into a single, unified effect and displayed in a flat list inside the Audio Effects folder. When you apply an audio effect, Premiere Pro automatically applies the correct effect type (Mono, Stereo, or 5.1) to that clip. For a list and descriptions of the available audio effects, see Audio effects and transitions.

Certain effects have restrictions, and can be used only on certain track types. (For example, the Balance effect can be applied to stereo tracks only, not mono, or 5.1). The following effects have this restriction:

In the Audio Track Mixer, track effect options are controlled after an effect is selected in the Effects and Sends panel. If the Effects and Sends panel is not visible, display it by clicking the Show/Hide Effects and Sends triangle on the left side of the Audio Track Mixer. The Effects and Sends panel contains Effect Selection menus to apply up to five track effects.

Premiere Pro processes effects in the order they are listed and feeds the result of an effect into the next effect in the list. Therefore, changing the order of effects can change the results. Effects applied in the Audio Track Mixer can also be viewed and edited in a Timeline panel.

In the Audio Track Mixer, effect options that change over time can be recorded using the automation options or specified in a Timeline panel by using keyframes.

Apply a track effect

To apply an effect in the Audio Track Mixer, do the following:

Remove a track effect in the Audio Track Mixer

To remove a track effect, click the triangle to the right of the effect you want to remove, and choose None.

Bypass a track effect in the Audio Track Mixer

To bypass a track effect, toggle the Effects Bypass button near the bottom of the effects list.

Copy and move effects in the Audio Track Mixer

Using the Audio Track Mixer, you can move, copy, and re-order audio track effects. This is useful in scenarios where you want to rearrange effects in the track to change the gain staging and signal flow of the audio.

Adjust audio track effects in the timeline

You can adjust the fixed audio Track or Panner effects either by manipulating the track keyframes rubber-band, or by using the controls in the Audio Track Mixer.

Copy and paste track effects in the timeline

You can copy track effects from one section of a track and paste them into another. When pasted, the track effect keyframes land at the location of the current-time indicator. Targeting tracks do not affect the position of the pasted keyframes.

Designate a track effect as pre-fader or post-fader

An effect can be applied pre-fader or post-fader. The difference is whether the effect is applied before or after the application of the track’s fader. Effects are pre-fader by default.

• Pre-fader delivers the signal out of the mixer before it passes through the channel fader.   Therefore, you can move the volume fader all you want but it's not going to affect the volume going to that auxiliary unit. 
• Post-fader delivers the signal out of the mixer after it passes through the fader.  Therefore, when you move the volume fader, the aux send volume is equally manipulated. 

In the Effects and Sends panel of the Audio Track Mixer, right-click (Windows) or Control-click (macOS) on an effect and choose Pre-Fader or Post-Fader.

Channelize effects

Effects channelization allows you to create custom layouts of your effects. You can then choose to save your custom layout as a preset, and reuse it. Use this feature if you have multiple audio tracks and you want to apply effects only to a subset of channels.