The worst is when someone walks over and starts talking but no one knows who they are talking to: Just me? My boss? Everyone? Is it rude if I don’t look and con

The worst is when someone walks over and starts talking but no one knows who they are talking to: Just me? My boss? Everyone? Is it rude if I don’t look and continue to focus on my work? Everything can be heard and seen in an open office so I think it makes communication worse.