I don't sleep on this ear either. But I tried to last night ( thought gravity might help) but I couldn't stay in that position for long before my side bothered me. It doesn't feel very plugged but if I put my hand over my clear ear it's hard to hear. The biggest annoyance has been hearing a sound and thinking it's coming from one direction when it's the opposite. Or I suddenly hear a sound but can't figure out what it is.