You didn't mention what kind of computer you are running. If you are running Windows all you need is a way to hook up your bass to your PC mic input through probably a 1/4 inch to minijack adapter. The software to hear your bass is built in
. If your Rocksmith software also installs audio drivers accesible from Windows, you can probably use your Rocksmith cable and DAW software like Reaper
, set the input to your Rocksmith cable device and do your monitoring that way. There may be delay and sound quality issues however as mic inputs on PCs aren't exactly designed for high quality audio. You best bet is to get a small mixer or practice amp and practice that way rather than going through your computer even if the Rocksmith cable has user accesible drivers.