I did this for a long time but stopped because I thought it looked too tin-foil-hat-like. After seeing Zuck do it, I think I'm going back. But why the audio ja

I did this for a long time but stopped because I thought it looked too tin-foil-hat-like. After seeing Zuck do it, I think I'm going back. But why the audio jack. I don't own a Mac. Do I understand correctly that he taped over a 3.5mm analog audio jack?