Lately when I sign in to Astrogab I get an alert signal randomly throughout my session. It is a tweep, tweep sound. I have checked alerts and there is nothing there. Is this indicating users logging in?
It's probably not the same thing but for a couple of days I had been using my headset and in the background I could hear something like what you are referring to. After a bit of searching I tracked it down to a chat that was taking place here, at least I think it was here!! Now see, if I had scrolled down a bit further I would have realized it had already been answered! Sheeeesh!
When I first joined astrogab I fell asleep with it running and had no idea what that sound was , it would just go off randomly(I thought) through the night . X D