@Sven talks about converting to MP3, but the title makes me think it’s about normalization. This is what Barry Diament had to say about it.
““Normalization” (I call it abnormalization) is a means of raising the level of a digital recording so the peaks reach maximum level. This is a trap many semi-pros (among others) fall into. When done for an album project, it results in “quiet” tunes that sound louder than the “loud” tunes. In addition, when done to a 16 bit recording, as is often the case, this results in truncation of the low order bits (which carry a lot of important musical information), adding harshness and obliterating the stereo image by losing important spatial cues.” - BD