https://www.rospa.com/rospaweb/docs...s/headphones-as-a-driver-distraction.pdf

“In the UK, it is not specifically illegal to drive while wearing headphones, but if the police believe a driver was distracted or not in full control of their vehicle, the driver could be stopped and penalised. Rule 148 of the Highway Code also states that safe driving and riding needs concentration, and therefore drivers and riders should avoid distractions such as loud music that could mask other sounds.”