Use the A/V Sync button in the Player Setup menu to force audio sync with video, even in cases where you play clips at a different framerate:

• With A/V Sync enabled, audio and video play at the framerate set in the FPS field.
• With A/V Sync disabled, video plays at the framerate set in the FPS field, but audio plays at the project's framerate. The project's framerate appears on the Desktop in the Format menu.

For more information about working with audio, see Audio.