I've kept up with this thread, wondering if the low range hum I hear is just tinnitus. But I think that is pretty close to what I hear! I only hear it when things are quiet and usually my high range tinnitus takes the fore.
Yeah, the hum is not tinnitus. I have tinnitus- the high-pitched almost 'white noise' sound in the ears (which is stronger in the right ear on me)- and can hear the low rumbling 'hum' in the background. The two are separate.