So the outlet cover acts as a drumhead transmitting vibration to the electrical current? Regardless whether one can hear the differences between types of covers, that "explanation" makes absolutely no sense.
Freemand, make a video tape of you describing the differences in sound between outlet covers you observed and post it on YouTube. I guarantee that you'll have your 15 minutes.
Freemand, make a video tape of you describing the differences in sound between outlet covers you observed and post it on YouTube. I guarantee that you'll have your 15 minutes.