My dogs do, I suppose mainly because of how I've trained them. Up close line corrections are very short, non-intimidating bursts. Louder, longer bursts mean trouble (like a very bad cheat). Regular sit whistles are short, but loud (or louder depending on the wind, road noise, etc). But as a Lardyite, I've heard at the workshop: "put emotion in your whistle". Large blasts up front (within the first 40 yards say) can really break a dog down... Short, lighter toots can help a dog stay relaxed and not get intimidated up front on a blind.
So, yes, I do feel that volume can affect a dog. And like LFL mentioned, wimpy whistles can be useless.
Depending on what you're getting at, Doc, whistle DURATION can be just as important as volume.
-Kristie