A PowerPoint presentation can include sounds from various sources: narration and transition sounds, audio objects, videos and emphasized text. Animations can play sounds as well. You can remove all the sounds from your presentation one type of sound at a time; unfortunately, there is no option to remove all sounds from all slides automatically.
Remove Narration and Transition Sounds
Switch to the Slide Show tab, click the arrow below Record Slide Show, select Clear and then click Clear Narrations on All Slides to remove the narration from all slides simultaneously.
To remove the narration from only the selected slide, click Clear Narration on Current Slide.
Select the slide that contains the transition sound, switch to the Transitions tab and then select (No Sound) from the Sound drop-down box in the Timing group.
Audio Objects and Video Sounds
Select the slide that contains the video box, select the video and switch to the Playback tab. Click the Volume button in the Video Options group and select Mute from the menu.
Select the audio object on the slide and switch to the Playback tab that displays. Click the Volume button in the Audio Options group and select Mute from the menu.
Removing Sounds From Emphasized Text
Although hyperlinks are usually enhanced with sounds in PowerPoint, any text can play a sound when you click or mouse over it. Enhanced text is highlighted and looks like a hyperlink.
Locate the enhanced text on the slide, select it, switch to the Insert tab and click the Action button in the Links group to open the Action Settings dialog.
Uncheck the Play sound boxes from both the Mouse Click and Mouse Over tabs to remove the mouse over and on-click sound effects. Click OK to apply the changes.
Remove Sounds from Animations
Select the animated element, switch to the Animations tab and then click the small arrow in the bottom right corner of the Animation group to display the Appear dialog. Select (No Sound) from the Sound box and click OK.