Here is the comic page explaining it. Though having done some research, it appears it was abandoned pretty quickly because of flaws with it. Source 1
Also, another idea that was presented by the comics was that of demeanor, presence, and body language. Which admittedly, was already pretty common idea some had to explain it. Source 2
Edited: Thomaslee on 10th May, 2017 - 3:10am
I have always wondered this, how can they not know! I can see the masked super heroes getting by but even their voice is a giveaway like Spiderman's but the one's with no mask it is so obvious.
If it some random joe pass by I can understand, but it don't help that clark kent work in news media company and graduate in journalism, wouldnt his classmate found out? Or maybe that's the reason, as he know how to escape from the journalis attention.