Normalizing audio waveforms code implementation (Peak, RMS)

1. What is RMS normalization?
2. What level should I Normalise audio to?

What is RMS normalization?

Audio normalization is a fundamental audio processing technique that consists of applying a constant amount of gain to an audio in order to bring its amplitude to a target level. A commonly used normalization technique is the Root Mean Square (RMS) normalization.

What level should I Normalise audio to?

So you can use normalization to reduce your loudest peak by setting the target to just under -3 dB, like say -2.99 dB.