The VK autos are not activated by sound. They work off the suction when you draw on the carto.
You don't want to get them too close to magnets, though.
Thanks, PawPaw, I've written that half a dozen times to various comments by people that don't use the 808-type, but they seem to gloss right over it and ignore what I've just said. Maybe you'll get more traction than I!
I'm auto-all-the-way - at least until I perfect my new auto-manual - or is that manual auto? No, definitely auto-manual. A manual with no button or other obvious activation method.