Sound barrier

I was getting my washing in, when I heard a plane or planes, going through the sound barrier. This is so unusual as I live in a city.
I wonder if anyone else heard them?
I wonder if anyone else heard them?
Fighting back against carers isolation
https://www.chill4uscarers.co.uk/forums/
https://www.chill4uscarers.co.uk/forums/viewtopic.php?f=11&t=53087