The subject heading above makes this question sound more esoteric that it is, but give it a chance.
Plainly stated, I’ve been listening to Paul Desmond (of Dave Brubeck fame) lately and am wonder if Desmond’s loose embouchure and airy sound were deliberate. Stan Getz also had a somewhat airy sound at times, and Ben Webster was a airy as the bed of a truck racing down a highway. When asked about his trademark sound, in fact, Desmond responded, “I think I have an illegal embouchure.”
I always thought a loose embouchure was the sign of a rookie–of poor mouth control–but these musicians were at the top of their games. Truth be told, the leaky air sound sometimes drives me nuts.