(I had also lost much of the hearing in my left
ear, which is why they did so many tests. One thing’s
for sure, I still hear the ringing!)
You mention a “swooshing” sound, and I recall experiencing something similar when the hearing problems just started. I would get a swooshing sound in my left ear, sometimes with bursts of clicking/popping sounds, especially when I first stood after sitting or lying down for some time.