Here are some instructions on using Audacity. If you’re using a laptop + mic for your recording, and want a bit more control, this might be for you:
Firstly, include 30 or so seconds of the recording when you aren’t talking so that you can use that to filter background noise.
All of the following are in “Effect”:
- Noise Reduction – Select the “empty” section mentioned above, go to effects, select noise reduction, and click “get noise profile”. Then select the whole track, go back to noise reduction, check that the settings are 12; 6; 3 (this should be the default), then click OK. You can do this many times to makes sure that the sound is completely gone, but I have never had to do it more than 3 times.
- Compressor – default settings should be good – OK
- Normalise – OK
- Filter Curve – OK
- Bass and Treble – OK
- Limiter – OK
- Loudness Normalisation – Set to -21 – OK
This should clean the audio up.