I'm not sure what makes me think of certain females as D-cup. I first became aware of it while listening to an episode of "Charmed"; I think that it is a combination of how high heels and the resultant thrusting out of the chest area affects the voice. It's not that the woman may be actively trying to produce that breathy tone which our culture associates with sexy women, but that the heels, tight skirt, and the constriction of the upper body due to push-up bras and other "body shapers" conform the body to the posture where producing anything *other* breathy speech is impossible.

I note that the Holy Grail of synthetic speech is to produce the sexy female voice. Every few years, I run across someone who tells me that programmers are still working on this, and that breathiness seems to be the tricky part. How to tell the little dears that it's going to be difficult to reproduce that when there are no lungs to add the breath part?