Insert an audio file within your PowerPoint slide, and choose to play it either with a click or set it to play automatically. Whichever option you choose, some files can sound loud and unexpected! Have you not experienced the sudden scare or shock when a shrill voice interrupts an almost silent environment? Rather than shake the soul of your audiences, you can use PowerPoint’s fade options to add a gradual increase in the volume of your audio files. PowerPoint provides both Fade In and Fade Out effects that you can add to the beginning and end of your audio clips. These fade options make your audio clips sound smoother and more subtle.
Fade in or fade out your audio clips in PowerPoint 2016 for Windows.

