Audacity
https://www.youtube.com/watch?v=TYF5ytMDFpA
- Noise removal: noise profile with selection -> noise removal for the whole
- Compressor: -15~-20db
- Equalizer - bass boost - treble boost
- hard limiter -3
- normalize
https://www.youtube.com/watch?v=TYF5ytMDFpA