Board Thread:General Discussion/@comment-5413572-20150517032258/@comment-26217701-20150517043339

They don't give out sound waves. The Steven example is the only one that makes sense, since some sound frequencies interact/disrupts certain things. Maybe the sound/reerberations of the water ball bouncing off the shield disrupt the forms of the clones. And Garnet singing was probably just a plot device. Or maybe the singing was used to convince Jasper that Garnet was better than her (psychological warfare if you would.)