When I was at primary school, if someone broke a rule or did something deliberately naughty, we would make an ummmmmmmmmmmmmmm! sound, with the inflection rising then falling.
My husband (who comes from the West Country) says his peers used the same inflection, but with an 'ah' at the end: ummmmmmmmmmmmah! A friend once told me that where she came from (Northern England), it was a similar inflection, but the sound was ooooooooooooooh!
I've asked my teenage children about this, and none of them have any idea what I'm talking about. Was it just a 1980s thing? Does anyone here remember children doing this? If so, what sound, what part of the world and which decade?