Well I think it’s best to learn pranayama from one’s teacher.
So if that particular pranayama, which was taught by your teacher “recently”, did not get INTO you, then it is most appropriate to revisit the topic with he or she.
That having been said, the exhalation breath in Ujjayi is much like the exhalation breath that fogs up your mirror or spectacles before wiping them clean - except the mouth is closed. The sound of the breath however is in the throat not the nasal passages.
The epiglottis at the back of the throat is much like the thumb over the end of the garden hose, thus gently regulating the exhalation.
I hope this is helpful but please address this with your teacher.