A neighbour was having cavity wall insulation installed. This seemed to be polystyrene beads about 3mm diameter blown into a hole drilled from the outside. The machine makes a prodigious racket.
A truck was parked on the road and a massive compressor started up. The noise increased when the beads were loaded up, from big plastic sacks. Job was done in a day and a bit.
I still wonder what happens to that sort of thing in a fire. It’s better contained than the ghastly polystyrene tiles people used to insulate ceilings with decades ago. This continued until the fire brigade public service ads on TV about what happened in a fire. Polystyrene still produces nasty fumes, however.
Probably recorded with an Olympus LS something XY