I chose this bitrate after listening to on headphones, select songs from several of the albums I own, going back and forth from 320kbps MP3 (LAME) to various Ogg Vorbis bitrates. 160kbps was where I could no longer tell the difference. So I chose 192kbps, figuring that the road noise in my car would overshadow any imperfections I might hear. So far, neither I nor any passengers have noticed any impurities.

So, your ears are much better than mine. And I'm not surprised; I've had problems with them all my life.