Bulbs work well at all 3 brightness levels no noticeable hissing or buzzing . When first switched on, the light switches on with a short delay. They work in my switchable 3-position lights (physical rotary switch with 4 positions, 1 off, 3 on). They do NOT work in my 3 position touch sensor. lamps. They just can't get in. I was hoping there would be some, but I'm not surprised they aren't. I haven't found an LED lightbulb that works yet.