Powerpoint 2016 adjust audio levels

Here are the steps. You can decide whether this is too much work or not:

1. Download the free Audacity sound editor from here: Audacity for Windows and install it.
2. Download the audio convertor files from here (choose the green button at the top of the screen): Lame/FFmpeg Audio Convertor
3. Follow the instructions on this page to install the audio convertor: Installing Lame/FFmpeg convertor
4. Make a copy of your presentation to a new folder.
5. Change the file ending from .pptx to .zip. Click on OK when Windows warns you.
6. Right-click on the zip file and expand all.
7. You'll see a {Content_Types].xml file and 3 folders appear.
8. Open the ppt folder.
9. Open the media folder. Your narration is the file called media1.m4a. Open it in Audacity.
10. Listen to some of the file to get a reference for how loud it is to start.
11. Choose Effect>Amplify. +10db sounds about twice as loud, that's a good place to start.
12. When you get the track sounding loud enough, save it.
13. Copy the file back into the media folder replacing the old version.
14. Zip the [Content_Type].xml file and the three folders into a zip file.
15. Change the ending back to .pptx.
16. Open it in PowerPoint and see how the narration sounds.