I can relate, Melissa. I usually look for a source when I hear something, and it's a relief to find one. When I can't find one, I get kind of creeped out, knowing that I'm hallucinating.

Once, I was in a coffee shop when I looked outside to see a bush on fire. The fire didn't grow, and the bush did not appear to be burning. It was really weird, and I thought that I was having a visual hallucination. Then I realized that the fire was actually just a reflection in the window glass from the shop's fireplace! Haha.