Something electrical running even when car is off and key is out.

It may have happened in the same general time spans but I don't believe they're linked. The whining sound as I call it happens whenever and randomly. I couldn't take you out there at any given moment And know we'll be able to hear it. I usually notice the sound when the car is off. Of course I blare my radio. ( I too have the cowl noise problem) lol. It doesn't always kill the battery when I hear it. I kind of assume that's the cause of the dead batteries. I do know I need new battery now too. No light is associated with the whining either? But it was on last time I was in it. I know it has several problems. Some of which I have diagnosed and just researched solutions to (how I found this page) and the ones I need masters help with... haha