This may have been fixed a couple of days ago. Try the absolute latest master dev version (at this moment 4.0-3334) and see if the problem is still there.
You're right - I just tried 4.0-3334 and it goes in-game. Sound is still distorted and crackly though even though it is clearly running fullspeed.
While async audio and VBeam+Audio framelimit will get the sound working, I'm sure the devs can find a way to fix the audio without resorting to hacks. It's a matter of figuring out what the game is trying to do, what we know real hardware does, and finding how Dolphin's implementation can emulate all that.
Of course - and the game only runs at 75% speed anyway with the audio framelimiter on so its hardly a *good* solution. Hacks are never the optimal way to do something, but until a dev shows interest in this game its the only option really except to play it on the real wii (and I don't have two classic controllers!)
Logged two bugs for this game already, not much more I can do.