Hi, Pilot,
I'm so glad you went into detail about the type of PT you have. Mine is similar to what you are describing --- high-pitched, constant hissing sound, along with pulsatile tinnitus. I've had mine for nearly five years now, and yes, I did have regular tinnitus in the same ear before this occurred. It wasn't very bothersome back then.
My pulsating occurred when I took a blood pressure drug for the first time, and my tinnitus got worse at the same time. The fact that you went to Dr.Eisenman, and he said that you should take a wait-and-see approach, makes me think that is the right thing to do in my case, too. My PT has gotten better, and I'm able to sleep pretty well now, so I would say things are going in the right direction. In the beginning, I went to several ENT's and neurotologists, who all said just about the same thing -- that they couldn't find anything wrong, and that I would probably have to "live with it".
Please do stay in touch, and keep us posted on how you're doing. I hope yours continues to improve over time. I would trust Dr. Eisenman's advice; he has a very good reputation in working with people who have PT.
Best wishes,
Karen