(page 109) he starts talking about wearing headphones while riding... Keep in mind that this is in the early 80s (remember the Walkman?)... Anyway, a bit of his Libertarianism pops up as he complains about states that are (were) passing laws to prohibit this for safety reasons, and he thought it really ought to be a personal freedom, an individual's choice to decide for themselves if they should or shouldn't wear headphones...
I disagree with Shermer's point back then, I stopped wearing earbuds a while back due to safety concerns. I noticed that other cyclists who wear them have the volume up loud enough that they can't hear my bell, horn, or shouts. When I would wear them, I was always consciously keeping the volume low enough in order to hear for traffic, but not low enough that I could hear other cyclists and pedestrians. After a few close calls where I was at fault, and a bunch of close calls where another oblivious earbud cyclers were at fault, I've sworn it off. I will miss my podcasts and audiobooks on my long hauls and during my commutes. But safety first, both mine, and everyone else's.
*Edited due to atrocious grammer (what else is new).