Linda,
Thanks so much for posting that audio link on cafepress! Their featured CD also includes traffic noise, the one thing that really causes Trevor to cower.
Not that I want him to be comfortable around traffic, of course, but if a garbage truck or any really loud vehicle goes by while we're walking, he will start jumping and spinning around to the point I am afraid he will either slip his collar or choke himself. Maybe this will help.
-Debi