I suggest the use of flutist Keith Underwood's system of Jurassic breathing to make an aural connection between inhaling with an open throat and mouth and inhaling with the interior of the mouth and the throat too closed. A multiphonic note is sometimes produced on third line B-natural. Some clinic participants described an almost ech-chamber kind of sound. Airy sound, fuzzy.
Balance is everything.
Clearly, there are tonal problems associated with too little and with too much lip pressure. Pinched sound Increasingly low in pitch ascending to high register. One of the more common problems associated with less than optimum tone. One clinic participant described a sound like blowing through the eye of a needle. Strident was the word the seemed most frequently to come to mind at the clinic.