Audio on a PowerPoint slide can be played when you click on the audio icon on a slide.
Choose the audio icon then on the Playback pane, choose Start: when clicked on.
You can have multiple audio tracks on a slide, each one plays when you click. This slide has two sound effects for either a correct or wrong answer.
Tweaking the PowerPoint Audio icon
The audio icon doesn’t have to be that dull grey default.
You can tinker with the look of the icon on the Audio Format | Adjust tab. All the usual choices are available including color change, artistic effects etc.
Change the icon size from the ribbon (at right) or use the border handles.
It’s also possible to change the PowerPoint Audio icon, though Microsoft decided to make that harder than it should be.
Audio is added to the .PPTX
Keep in mind that any audio (or video) file inserted into a PowerPoint presentation is copied into the .pptx file. That can make the PowerPoint file very large.