How to convert .mpa audio files to .mp3 format.
Converting MPEG-2 Audio Files directly to MP3 Audio Files (.mpa to .mp3 conversion) is possible and should be quite straightforward.
Use an audio editing software or (online) conversion tool, such as Adobe Media Encoder or Tiny Audio Converter, which allow users to import MPA files and export them in MP3 format.
Multimedia encoding application from Adobe
Audio converter for Mac
An audio converter and audio-grabber for Windows