Where we live sometimes lads from a nearby estate come riding, helmetless, on their motorbikes at high speeds. They take the silencers off the motorbike's exhausts so the bikes make a very loud sound in between a very loud angry giant wasp and an air raid siren. It is a very sinister sound. When they do it during daylight hours everybody stops what they are doing and has a look, which is probably what they want.
My Mum was doing a late evening walk in the dark along the deserted pavement when she heard this sound in the distance getting louder and louder as the bike got nearer. Even though my Mum knew it was a couple of daft lads she got spooked.
The sound then retreated again as the bike changed direction and my Mum breathed a sigh of relief. She started walking faster.
Suddenly the sound started getting louder and louder and my Mum felt like she was being pursued by an unknown malevolent entity who had worked out where she was and was coming to get her. She made for the snicket (a path lined with fences through a built up area) and the sound got louder and louder until it was deafening, my Mum's heart raced and the idiots sped past her through the snicket.
My Mum thought it would be a good idea for a film.