At least three Pac-Man games were developed by Full Fat for the GBA; it's these specifically that have issues, not any of the other Pac-Man-related games that are also on GBA.

The three games in question are (No-Intro naming and ignoring regional variants):

• Pac-Man World (USA)
• Ms. Pac-Man - Maze Madness (USA)
• Pac-Man World 2 (USA)

Bonus:

• 2 Great Games! - Pac-Man World + Ms. Pac-Man - Maze Madness (USA)

These games are all ports/adaptations of console games, and are somewhat rare among GBA games in that they all use very compressed versions of the original streaming audio from their disc-based progenitors. It already sounds a bit garbage-y when it's working correctly, but in mGBA and other emulators, there is a significant amount of quite loud crackling introduced in these games. I've seen hardware video of Pac-Man World 1 and tested Pac-Man World 2 on my own hardware and can confirm the audio being "fine".

I haven't actually tested or seen it confirmed that the Ms. Pac-Man music works properly on hardware, but I mean it probably does, right?

This issue doesn't seem to relate to performance, the games are running solidly at ~60FPS, so it's not slowdown-related as far as I can tell. Presumably some minor timing issue? Confirmed issue on latest Windows build and like a ... week old 3DS build from the buildbot.