Not a sound but a sight that will stay with me for a long time-
following a 38 tonne artic truck along a dual carriageway, big pigeon in middle of lane pecking at something. Pigeon suddenly realises that it is about to die so it takes off, flying along the road in the middle of the lane. I see the truck catch up with and drive over the pigeon. A big swirl of down emerges from under the truck, in the same fasion as vortices of condesation swirl off the wings of a figther jet. The pigeon then emerges in ragged flight from between the tractor unit and trailer and manages to fly to a fence post where it lands. I last sw it on the post, wings haning down by its side, head down, panting, with a look on its face that just screamed '**k me- that was close!'.