I have an mp3 which I increased the volume with Amplify but now the voice is talking as if he did it with the loudspeaker of the phone (more or less to be understood) and wanted to know if it is possible to improve it with Audacity.
The BIG problem with MP3 compression damage is that it can’t be fixed.
The MP3 format compresses audio to a smaller size by throwing away the “less important” audio data. The more data that is thrown away, the smaller the file size. This damage cannot be fixed because the missing data has gone forever. We always recommend that people use uncompressed audio formats (such as WAV) whenever possible so as to avoid this problem.
You will be companding the MP3 compression damage. When you convert the MP3 to WAV, sure it becomes a “lossless” audio - but it still contains all the compression damage done in the initial MP3 compression - so the stuff that was thrown away in the compression is lost forever.
It’s a bit like taking a packet of chicken soup, adding the water and then reducing it to powder - and then making the “sup” again. Neither of 'em tastes like real chicken soup - but the latter one will definitely be the worst