I hate to say it, but I think it contains an error.
In both DefaultCloak and DefaultDecloak you reference a pSound, a variable which does not exist in any accessable scope, I suspect it will give a nice NameError when you try it.
I'm also not entirely convinced that "App.g_kSoundManager.StopAllSounds()" is the right thing to do either.
I also don't think you are stopping the currently playing sound. You do call "App.g_kSoundManager.StopSound(sCloakSFX)" this, but this is the new cloaking sound, not the stock one.
It also won't work in, for example, cutscenes in a different set than the player set, but I suspect this case won't happen that often.
I'm terribly sorry to be so negative about this.