Usually yes, but I'm not sure how well the USB receiver will react. There's quite a bit of handshaking going on. Try it.
I suggest you only have one cable connected at a time if you are comparing input types or cables. Since a lot of the potential difference may be some form of noise transmission by the cable, having both connected at the same time wont remove that variable. The best advice I have heard is to have only one connection at a time connected when you are making a comparison.