Cancer

I can hear it whispering in my head. It's been about 12 year when I started noticing. A small murmur by the lower back of my head, close to my right ear. At first it sounded like a part of my heart beat, only slightly dysrhythmic. I thought some water had gotten stuck in my ear canal after a shower. But it didn't go away. i went to the doctor to see if it was a bug nesting there or something. They found nothing.