Possible Malware

I am cleaning a friends computer since they have been having some serious issues with the machine. I've been able to track down majority of the issues and get them taken care of. There is one issue I am unable to track down, and honestly, I am not sure of what it is. My assumption is that it is Malware, but I'm not for sure. Any help would be appreciated. Allow me to explain the issue.

Randomly, and for periods of 5 to 10 minutes, the machine randomly begins to play audio. It appears to be nothing in particular that is played. I've heard a geek.tv podcast, and some other random things. Problem is, when it plays, and when it doesn't, there are no signs of it in the processes or the running applications. I've ran SpyBot, and Ad-Aware, as well as avast! none of them are finding anything. Any thoughts on this?

Thank you.

 

Nevermind, this problem was solved.