Silence Has Never Sounded So Good Silent Brass Systems (a set of a moudule and a mute) For Trumpet Yamaha's Silent Brass System offers the advantage of practicing or playing at times, and in places you couldn't before. And offers privacy for those a bit timid about having others hear their not so perfect notes. Simply plug in earphones to hear yourself in your own personal performance environment. The internal electronics can also enhance the sound digitally, to mimic the acoustics of a larger room. You can play along with your favoite pre-recorded music by plugging in a CD favoite pre-recorded music by plugging in a CD player and use the output jack to connect to an expternal amplifier or recorder to share your music with others.