Thanks. Struggling to explain it. All I know is that after about an hour of driving there is definitely some ache in my ears. I don't think its road noise (it has 18inch wheels and appears quiet) as there is a clear relief when the drivers window is opened.
I will try a combination of trying air recirculation, adjusting radio settings etc tomorrow to see if I can work it out, however I am a little worried that I may not be able to identify it so would be grateful if anyone could offer any possible solution.