I'm currently talking to Dell regarding a replacement, but have also realized that many people seem affected and a replacement would probably persist the same issue.
I've tried updating and reinstalling the audio drivers with no luck. Really love the laptop, but it's a major let-down. Let me know how it goes. They told me they'd schedule an appointment with an engineer to overlook the laptop, so I'm considering doing that and seeing if they find some software issue that is an easy fix. The more people we have write to them the more likely they'll develop an update for everyone to use.