I don't know what it is, but my iMac every so often makes a popping noise out of the speakers. I was thinking that maybe it was growl giving me some sort of notification, but I never saw a pop-up from growl. Any ideas what may be causing this noise? It happens a couple times a day and I haven't changed what I do on my mac. So I'm not sure what it could have been that I did. Thanks for your time!