Troubleshooting

[Browntail]

Should work fine on lion as well. maybe try to completely uninstall the game, including deleteing the frictionaö games folder in home/library/application support/ (will delete saved games) and do a fresh install.

I did a full uninstallation and deleted the Frictional Games folder. After downloading the game and going through the process of the introduction and creating a new profile, the same effects take place: Great framerate and smooth gameplay until a sound plays (Collision, triggered sound, footesteps, even music). Each causing a half second long freeze.
I gave Justine a try, just for the heck of it. That game also has the same effect.