R' Micha Berger <micha at aishdas.org> wrote, in part: <<The American /r/ can be approximated using pretty much any part of the tongue. A listener can't year if you're raising the tip or the back.>> That depends on the listener. Michael Hamm AM, Math, Wash. U. St. Louis msh210 at gmail.com <-- Note new address! http://www.math.wustl.edu/~msh210/