I occasionally carry one, so clearly the sound doesn't bother me. To me, any psychological advantage that the sound of extending the thing may inflict is offset by losing the element of surprise, which is one of the major attributes of the collapsible baton. My personal favorite tactic with an ASP is to discretely hold the collapsed baton in my right hand while standing with my arms crossed, so that the baton is fully chambered for a back hand strike with no wind up and no warning. Nasty.
_________________
Your boos mean nothing, I've seen what makes you cheer.
- Rick Sanchez