Slideshows are usually not, accompanied by a lot of speakers, so it is no surprise that you sometimes need to pause the sound during the presentation. With PowerPoint you can do it at the touch of a button.
Pause sound during a presentation
If your presentation is not intended to be displayed without a speaker (like a slide show full of images for an audience to observe during a wedding), it will likely be a point when you need to pause the sound to answer questions, talk longer about a topic than what is supposed and so on. Fortunately, the pause sound is extremely easy.
Open up the presentation with which you are going to work. Go ahead and insert your sound if you have not already done so.
When you're ready, start your presentation. To do this, select "From the beginning" in the "Start slideshow" section of the "Slideshow" tab. You can also hit the F5 key.
On the image containing the audio file, you will find the sound icon.
If you hold the mouse pointer over the audio icon, a progress bar for the audio file is displayed along with a volume control and play / pause button. Click the pause button to pause the sound.
Alternatively, press Alt + P to pause and resume the sound.
That's all that is needed. The downside is that this option is not available if you play the sound continuously through the slideshow or hide the audio icon (even if you can still use the Alt + P key combination), then plan your presentation accordingly.