Can anyone help me with this?

I have been hearing pulsating tones. It is coming from outside my head. It sounds like when you leave your car door open with your keys in the ignition or your lights on. I keep looking outside to see if there are any cars like this and I don't see any. I've checked out my whole house to see if anything is making this noise. This can go on for hours. It drives me nuts. I've had it happen mostly at home and and once at work.

I'm also working on abuse in therapy. It doesn't feel like a flashback. I haven't talked to Pdoc about it yet.

Any advice?