This might be a stupid suggestion but did you make sure the volume on your guitar was turned up? I don't know specifically what all Rocksmith brings in from the guitar so I don't know if this affects ...

Rocksmith is the first and only game where players can plug any real guitar with a standard quarter-inch input jack, and play through an in-depth library of music including everything from the latest ...

With a completely redesigned interface and all-new features, Rocksmith 2014 Edition is tailored to better teach the key elements of guitar playing, and to make learning faster and more fun than any ...