I Whilst it's,not explicitly illegal to wear headphones or ear defenders while driving in the UK, but it's highly inadvisable and maybe dangerous, as it can lead to charges of careless driving if you miss road sounds like horns or sirens, resulting in fines (around £100+), penalty points, or even a ban if an accident occurs, because you must concentrate and avoid distractions according to Highway Code Rule 148
Thank you John good point, I'll look into the rules here in Sweden
