Those of us who go to concerts, and are not part of the deaf and hard of hearing communities, take sound for granted. We listen with our ears, occasionally move our bodies to rhythms and beats that we hear, and clap loudly when we are pleased with what we hear. But what if your world is soundless? How do you appreciate a concert? Sweet Honey in the Rock (www.sweethoney.com) has the key to this conundrum.