Try going to about:flags and enabling web audio (if you have that option.). Doing so will allow you to use native audio instead of data uri generation in real time. Kind of like mozAudio, but for webkit.
Hmm, enabling web audio API disabled the sound completely. Oh well. Still, a very cool emulator!
If the audio stops playing after enabling web audio, then you just ran into a bad bug in chrome. :P
I've run into this bug before, it seems to be a bug with the GC possibly in V8.
Horrid sound glitches on mozilla in windows 7 as well.
I'm guessing you're not using Firefox 4 then, I take it?
Edit: Firefox 4 on linux has a GC issue, not my fault.
Firefox 4 on Linux also has terrible sound.
Works fine here... ? ff4.0b11 / Ubuntu 10.10 64-bit...
Must be hardware specific then with the gfx cards.
damnit firefox.
4b11/Arch x64
Ubuntu has a GC issue for the canvas as far as I know of. Bitch to the Mozilla people to fix it. On Windows 7 and Mac OS X, it seems to work fine.
Same setup, same issue.
Use Firefox 4 for OSX and all will be resolved (I have Snow Leopard on a MacBook Pro, so it better work well on your Mac too). :P