You’re right, there’s not much that can be done with this. however, going forward I think we can help. How are you recording the Skype? Just having the far side much lower volume than the near usually means you’re not using Skype-compatible capture software. You can dig yourself a hole very rapidly by doing a Skype capture wrong.
And no, I don’t think it’s a data transmission problem because the near-side sounds bad, too. There’s no good reason for a transmission error to destroy the near-side voice. I was a party to a conference capture system that used a “dummy” conference participant whose job was to just hang on the data line to record and not talk. In that specific case, it’s possible to get all sides of the conference to sound funny in a network crash.
You can get a bad Skype capture system to completely screw up echo cancellation and that does affect both sides.
If your business depends on good clear recordings and you’re on Windows machines, Pamela is highly recommended. The two top licenses, business and professional will give you split, WAV recordings so you can process or filter each side of the conversation and then combine them into one clear “show” in post production.
http://www.pamela.biz/en/products/
There are other free products, but you are warned to stay away from software that insists on using lower quality MP3 files and that will not give you a split file.
https://forum.audacityteam.org/t/help-recording-with-a-mic-laptop-and-headphones/35068/6
Koz