Do you need to overcome the gadgets "object resistance"? (are you actually effecting technology or just reducing sound. I don't think the spell actually effect gadgets.
With Silence cast how many sucesses does it take to neutralize Ultra Sound technology?
Ultra sounds reduces the penalty to -3 in Total Darkness.
So, for an invisible character would each hit on Silence be a -1 until 3 hits then Ultra Sound stops functioning? Thus totally blinding anyone in total darkness who does not have Thermo and regardless of lighting conditions keep the invisible objects invisible?