I don't use them. I sing without them all the time, I don't play super loud onstage so it's not really an issue. You know how a sound man will sometimes get feedback in the monitors, try that with IEMs. I didn't think that feedback was even possible in those things, but yes it is! It's bad enough having a sound guy fry your hearing for the night (esp. high end) while getting levels in wedge monitors. Try getting blasted while wearing in ears by the super inexperienced guys doing sound at church. I had tinnitus for almost 6 months! Not to mention this guy fried 2 pairs of VERY expensive custom in ears for guys in the band. I'll never wear them again! Too dangerous! Not to mention they never seem to stay in my ears!