Hi lthompson
Though I'm not in the same situation as you I would hazard a "yes", there are others w/o significant symptoms and even much larger ANs.
Much depends upon tumor location. If your AN is in the IAC, Inner Auditory Canal, waiting 'may' not be as good an idea as Tx. Especially if you have an increase in symptoms. That would indicate the smashing and stretching of nerves against the bony IAC.
Re Tx; Oftentimes it is the Tx itself which causes proplems, but not always, so, "watch and wait" is prudent for 'some'.
If this were happening to me, I would want another opinion as to the hearing anomalies whether it's actually ET dysfunction, or, the tumor. Considering the response is so quick after beginning steroid, I'm guessing it's not the tumor also, but it seems reasonable to gain another opinion and by an Otologist. Possibly the hearing disturbance would have cleared w/o the steroid?
Does your ear feel full ( aural fullness ) with the hearing disturbance and what do you mean by disturbance? A loss of hearing or strange sounding hearing? Can you pop your ears during the episodes by squeezing the nostrils together, closing the mouth and attempting to blow, "gently"?! This is known as the 'val salva manueuver' and if there is a temorary relief, it may very well be the ET, allergy, or sinusitis.
Best wishes always!!
http://www.tchain.com/otoneurology/disorders/symptoms/etdysfunction.htm It would seem audiogram should be accompanied by Tympanograms, especially when you notice the symptoms.
Russ