Webcam as in posted all over the internet? I think you'd be better off using a "real" webcam. Sound is available, but not via the internet. I can observe using my iPhone, but no sound. Hope that helps.
According to Uniden, yes you can. However in my case it would not work and Uniden told me that there were problems using windows 7 with the system and as they could not give me any idea when a fix might be available I returned my unit. A very disappointing experienece!