Well, how about pointing to one for starters?  I
don't think I ever saw a
 etc. etc. 
Please, Richard.  I probably should've asked the
question to Sellam off list.
John A.
I am pointing to my nose.  The outermost joint of my index finger
is touching my closed mouth.  My wrist is below chin level.  I am
making a sound. etc. etc. etc.
The sound is Shhhhh.
Other people in the world, you know.