High Pitched Noise Nuisance

News coming in so not a lot of detail yet but...

Radio is reporting that British police in Surrey are planning to use a sound-making device which emits a high pitched noise audible only to people aged below 20!

Apparently hearing deteriorates after that approximate age so we oldies won't be able to hear it - but children and teenagers will dislike the shrill sound and move away.

It is to be used for clearing kids and teenagers from areas wehere they have been gathering and causing a nuisance.

Incredible... More to follow. If you know more, please post me.