Alarm

Yesterday during the late morning when I was studying in my dining room with all my apartment windows open -- it was a great weather outside -- there was this sound from the street outside my living room windows, and it sounded exactly like the beginning of the ring on my digital alarm clock, but it only went for 2 or 3 seconds, though it did this like 4 or 5 times over a 45 minute period.

I still have no idea what that could have been.