You can add sound effects and music to video clips in your project. iMovie provides several sound effects to choose from, and you can also use audio recordings from your GarageBand or iTunes libraries.
To attach a sound clip to video:
With your project open in the Project browser, click the “Music and Sound Effect” button in the toolbar below the viewer, or choose Window > “Music and Sound Effects.”
The Window menu appears in a light gray bar across the top of your computer screen.
Choose one of the options from the pop-up menu at the top of the Music and Sound Effect browser to focus your search for the music or sound file you want to add. If you don’t see the pop-up menu, drag the gray dot upwards to reveal it.
Browse to find the music you want to use in your project, or use the search field at the bottom of the browser to find an audio file by name.
In the Project browser, drag the audio file over the video frame where you want it to begin playing.
A green bar appears below the video where the sound effect is applied.
To move a sound clip to a different video clip in your project:
In the Project browser, drag the green bar to any other video frame or still image in the project.
If “Snap to Ends” is turned on (choose View > “Snap to Ends” and make sure it has a checkmark next to it), as you drag an audio clip in the Project browser, its anchor aligns with the beginning of video clips. A vertical yellow line appears when alignment has occurred.
The anchor of an audio clip is the point at which you “grabbed” the clip with the pointer to drag it. Because you can grab anywhere in the audio clip, this feature allows you to align specific parts of audio clips with video clips.
To delete a sound clip from a project:
In the Project browser, select the green bar that appears below the video clip; it becomes outlined in yellow.
Press the Delete key, or choose Edit > Delete Selection.
The Edit menu appears in a light gray bar across the top of your computer screen.
If the sound effect or music clip is too long, you can trim it. Go to this topic to learn how: Set the beginning and end of a sound or music clip.
If the sound effect is difficult to hear over the background music, you can make the volume of the background music automatically lower (or “duck”) when the sound effect plays, giving priority to the audio in the sound effect: Reduce the volume of competing audio clips.