The noisemakers that I didn't see mentioned include gunshots, tradition is three in a short time but even one tells people for a considerable distance that someone is there. In this a shotgun, for obvious reasons, would be better than a .22LR.

A vehicle stuck in the woods metal parts might be banged together to make noise. Even better if you can suspend a piece so it rings like a bell. Perhaps from a length of wiring torn out or a seatbelt. Older vehicles, with their larger selection of stout metal parts, like hubcaps, might be better than late model vehicles with less steel.

If you need to get someones attention the single most effective sound may be breaking glass. Whistles and shouting 'fire' don't evidently carry much weight in an urban environment. The sound of breaking glass was judged to be more likely to cause someone to investigate and/or call police.