It's not a beep that's directly related to my actions at the time the beep sounds (I heard it once while I had my feet up on the desk, reading a book over lunch. It's not a beep that is coming through my speakers (since I don't have any). It also resembles the chirping, fluttery beep you can get if you hold down a bunch of keys for a long time. It is a funny sounding beep it resembles some of the game music that early PC games had before they invented sound cards.
The beep sounds like it's coming from the front left part of the laptop. I do not have any speakers attached to the laptop. At various times when I'm sitting in front of my laptop (in it's Dell docking station), I will hear a short beep. I have tried several web searches on this, and there are lots of different reasons why laptops beep, but most of them either don't apply, or I tried the solutions and they didn't work. It will (apparently randomly) make a strange beeping sound a few times during the day.