Shock waves are not sound waves. If you look at a sound wave, and I'll give you a picture of it ¾ sound waves are sinusoidal, they go up and they go down, a shock wave goes up and then it decays. And so what happens when that happens is, if you have a burst of waves coming from one place, that one wave, the decay slows down and the others catch up with it, so what happens is there's a wave front that gets created, so that's what you see when a bomb goes off, actually, there's this shock wave. When patients ask me, what is it that's breaking up the stones, I use the bomb analogy. If a bomb goes off across the street, the building on that side of the street gets knocked over. There's this wave of compression that travels through the air and, in our case water when we're using antibiologic systems, that is absorbed when it reaches a different acoustical interface, the building, or in our case the stone.
There are multiple frequencies; as opposed to a sound wave which is all one frequency, shock waves have multiple frequencies, and this has something to do with what the force of the wave is and its destructive capacity. So on the left is the diagram of what a sound wave looks like, and on the right a shock wave. Again, there's a sudden impulse and decay of the wave.