I cannot fade a sound in my presentation
You cannot make a sound fade gradually, at the end of a presentation or at the end of a slide, instead of ending abruptly.
You added a fade animation to the sound icon, but the sound does not fade and the animation does not work.
It is not possible to fade sounds in Microsoft Office PowerPoint 2007, and the Fade animation applies to the slide, not to the sound.
Before you add the sound to your presentation, use a third-party, external audio editor (such as Sony Sound Forge Audio Studio) or shareware (such as WavePad by NCH Swift Sound) to make fades and other edits to the sound file.