Useful for dampening down live music without losing enjoyment, and for people like me with sound sensitivities. A little less dampening than Anybodysguess' design, though both allow you to hear voices well - even better than normal in crowded places, stores, restaurants etc.

Even a rough print works well, though it can use a bit of sanding with a nail file.

I'm going to make a few more versions when I have time.