Board Thread:General Discussion/@comment-25266931-20161223190810/@comment-26397825-20161227002937

In the Emerald Forest during initiation, when Ruby is just about to fall of the Nevermore, Blake's bow twitches and she looks up, eventually drawing Yang's attention to a falling Ruby. So while I don't know about twitching towards noises, they certainly do react to them and she can hear things much better than an average human, since Yang had no clue about the situation until Blake pointed it out.