@Stevenr109 Strange but true. I lived for some time in a house in a very quiet residential neighbouhood. On top of that, we had double glazing. It was very difficult for me to fall asleep because it was so quiet. Afterwards we moved to a house nearer to a busy street and the sound of the occasional car going past at night made it falling asleep a lot easier.
Hiss sounds like a badger. maybe it fits with the relatively heavy gravel-walk sound. These animals live at night. Look for holes 10-20cm wide hole in the ground with poo in it. No joke.. As you can see the live over there; http://www.youtube.com/watch?v=QRnjIXXL9lE