An audio track embedded in a slide, can be trimmed directly from Powerpoint (at the beginning and end of each clip), without the use of any third party software:
- On your slide, select the audio track:
- Go to "Audio Tools" > "Playback" > "Editing" section.
- Click on the "Trim Audio" button:
- In the "Trim Audio" dialog, use the green and red slider to trim your audio.
- Alternatively you can adjust your settings via the "Start Time" and "End time" Field.