Guest used built in laptop microphone - fix

a guest on my podcast used a built in microphone for his end of the conversation - any suggested fixes to get rid of the lack of crispness and dullness to his feed? lesson learned
thanks in advance

This works a lot better if we have a sample. Cut ten seconds of typical speech including a bit of silence, export it as WAV (Microsoft) 16-bit and post it on the forum. Scroll down from a forum text window > Attachments > Add Files.

The sound doesn’t have to be dreadful. My podcast demo had my interview on her Mac laptop built-in microphone.

If you’re doing this on Skype or Zoom, you can do a world of good if everybody is on headphones. All the voice management, noise reduction, and return path errors vanish.

I can’t prove this, but it’s good if you get there first. If the guest tried to fix it, then it’s hopeless. We can’t reverse many processing effects.

lesson learned

What was the lesson? Don’t use the built-in? Instead use what?