I Developed Vibration In My Ear/head 3weeks Ago. It Sounds

I developed vibration in my ear/head 3weeks ago. It sounds like a car idling. It first starts as a very slight flutter in my ear and then moves to two or more flutters before it takes on a rhythm of its own. It can do this for hours before it stops. I usually only get relief when I am sleeping. I never wake up with it. I saw an ent doctor and he said the inside of my ears look good. I'g scheduled for a hearing test and carotoid Doppler. I had a acoustic neuroma removed in 2008 and my last MRI was clear in 2014. Just hoping its not another brain tumor or any brain tumor! Any thoughts