There are quite a lot of old Feynman lecture recordings on YouTube, that unfortunately suffer from very noisy audio. I'm not a sound-design professional, hobbyist; in fact I'm quite possibly tone deaf. I am however an engineer, so I had to give it a whack.
I tried applying a couple of filters in Audacity on a sample lecture
- Automatic noise reduction filter,
- Low-pass filter for frequencies above 2 kHZ.
- High-pass filter for frequencies below 300 Hz
I was actually quite pleased with the results. Compare the two samples - original YouTube video and the filtered result. I would say that the voices in the original somehow sound more real, so there's room for improvement.
I'm looking for input and suggestions (filters, settings) on how to improve this further.