by Ken Task.
It's usually a good idea to provide some info about your server ..
Moodle version is? Linux or Windows or Other? etc.
How did you migrate moodledata/filedir/
That's where files are uploaded to a moodle. If moodledata was migrated via FTP was FTP using binary mode?
Assuming mp3 files for audio
Check:
Admin menu -> Server -> File Types
Look for mp3
There is a gear icon in that row - do those look right?
Upload an .mp3 file at your code root directory where one can simply use
https://yoursite/test.mp3
See if that plays
'SoS', Ken