a Ministry of Defence spokeswoman has said it's not believed to be linked to any RAF activity.
So far people in Dawlish, Cullompton, Teignmouth, Newton Abbot, Exminster and Torbay have all reported hearing the loud noise this afternoon.
Read more... https://www.devonlive.com/news/devon-news/sonic-boom-over-devon-aircraft-5209003
Apparently caused by a meteor.