You can add sound clips to a slide to emphasize a point or add some background audio to set a mood. However, make sure you don't go overboard because audio can be distracting.
Automatically: Audio begins when you enter the slide.
On Click: Audio is paused until you click the mouse.
Use the check boxes in the Audio Options group to adjust any other settings.
Play Across Slides: The audio will continue to play as you switch to the next slides.
Loop until Stopped: The audio will replay in a loop while you remain on this slide during the presentation.
Hide During Show: The audio icon will be hidden during the presentation.
Rewind after Playing: The audio will play once and then automatically rewind.
There are additional useful options on the Playback tab, such as setting the audio to fade in or out, trimming the audio down, or inserting a bookmark.
To remove audio, just select the sound icon and press the Delete key on your keyboard.