Premiere Pro: Audio Editing Tools - Trimming, Retiming, Adding Fades
Audio editing is at the core of most types of videos. Documentaries, reality television, interviews, and films all rely on rearranging spoken words to convey a certain idea. It is the editor’s job to move sound files around so seamlessly that the viewer never even considers that it didn’t start out that way.
Before the digital revolution, editors cut physical tapes and spliced them back together. The point where the tape was attached back together would overlap forming an analog crossfade that provided a smooth transition that wouldn’t attract any unwanted attention. These fundamental concepts of editing film still hold true today.
Trimming an audio clip is done by removing unwanted parts from the starts or ends of clips. In Premiere, there are a couple of ways to go about trimming.
Hovering the mouse over either side of an audio clip in the timeline will change the cursor to a red bracket/arrow symbol. Now, click and drag that side of the audio clip to extend or trim the length of the clip.
Another common method is to create cut points around undesired portions of audio and then delete that selection. This technique is more flexible because you won’t be constrained to just adjusting the end points of a clip.
In Premiere, select the Razor Tool from the toolbar, or use the keyboard shortcut C.
Next, place your cut points to isolate sections to delete. Now switch back to the Selection Tool (the cursor) or use the keyboard shortcut V. Finally, select the audio region and delete it. Multiple audio regions can be selected and deleted at once by holding Shift while clicking on any desired clips.
To make extremely precise trims, you might need to zoom in more than Premiere lets you in a frame-based timeline. Access the sequence menu by clicking the three stacked lines icon to the right of the sequence name, as shown below.
Enable Show Audio Time Units, and now try zooming in on your timeline. Premiere has switched to a sample-based timeline, allowing much more precision for fine-tuning audio. Toggle the menu option off to return to a frame-based timeline when you switch back to editing video.
Be aware of any linked clips, which means that the video and audio tracks of a clip act as a single selection. Linked clips make it easy to keep your media organized and streamline many aspects of editing in the timeline. However, it is easy to accidentally delete more than you intend to. With linked clips, deleting the audio would also remove any video clips that were attached to the selection.
To enable or disable linking in the timeline, toggle the Linked Selection icon which is the middle icon under the timecode display.
Audio fades are used in a wide range of scenarios such as cleaning up a recording or quickly automating the volume of a clip for a smooth transition.
Many times after trimming audio, there will be an audible pop or click sound when a clip of audio starts playing. This occurs because the audio goes from complete silence to full volume with no transition time. To fix this, apply a short fade in order to smooth out the transition.
The quickest way to add a fade in Premiere is by selecting the end of the audio clip and using the keyboard shortcut Ctrl/Cmd-Shift-D. Audio fade transitions can also be accessed in the effect panel and dragged and dropped onto the start or end of a clip. After the fade is applied, click and drag the start of the fade to adjust its length.
Crossfading is a technique that effectively transitions between two audio clips by automating their volumes simultaneously –– fading up the incoming audio while fading out the outgoing audio at the same time.
To add a crossfade, either select the cut point of two touching audio clips and use the Ctrl/Cmd-Shift-D shortcut, or drag and drop the effect to the cut point. Depending on your desired effect, adjust the length of the fade to make it happen quickly or gradually. Hold down Shift to adjust one side of the crossfade independently.
Types of Fades
Premiere offers three different types of audio fades: Constant Gain, Constant Power, and Exponential Fade.
Each fade differs in the way it fades audio in or out. Understanding these differences helps to make informed choices in any situation.
Constant Gain adjusts the audio at constant rate. This technique is seldom used because it doesn’t sound very natural to our ears.
Constant Power adjusts audio with a smooth curve that works well in most situations. It is the default fade in Premiere and gets automatically applied with the Ctrl/Cmd-Shift-D shortcut.
Exponential Fade applies a logarithmic curve to the audio, which means the transition starts slowly but speeds up increasingly as it goes on. This fade is useful for fading audio on or off in a short duration as well as eliminating pops and clicks.
As an editor, it is sometimes necessary to retime audio to achieve a certain length or effect. This could be speeding up a voiceover to make it fit or slowing down a sound effect to match the visuals.
Right-click on an audio clip, and click Speed/Duration. Here, you can adjust the speed of the clip or play it in reverse. Toggling off Maintain Audio Pitch allows the effect to get deeper in pitch when the speed decreases, and higher in pitch when the speed increases.
For faster adjustments, select the Rate Stretch tool by using the keyboard shortcut R. With this tool selected, grab the end of an audio clip and adjust the speed visually.
There are also dedicated pitchshifting effects available in the effects panel.
While Premiere has basic audio retiming capabilities, dedicated audio software will usually do a better job with this process. If you don’t have access or experience with programs like Pro Tools or Logic, try using Adobe Audition, which is included in Adobe’s Creative Cloud subscription.