Good MO, Leeneia; it also helps protect the ear from being blasted out, which I read once is one of the occupational hazards of manning (personning?) a helpline. Something I noticed many years ago is that sound coming in only one ear is perceived as being quieter than if it comes into both ears, so people on phonelines turn up the volume to compensate.

Real Soon Now, I'll have to write up that rant of mine on "How long is a long time?" [basically: much longer if you're mentally tapping your foot while you're busy-waiting on something].