Thanks chaps!
Paul, I wear a Large/Extra large (depending on brand)!
With the windjammer I don't think will make much difference as I have the chin guard as above and there isn't really any wind flow underneath the helmet because of the style of jacket I have and how it fits in with the helmet, when look at the AGV I have, There is nothing in the "ear space" padding wise, I do have my Bluetooth head phones there now but other than that its just some thin polystyrene and then the outer shell.
I think part of it is the shape of the helmet causes quite a bit of wind noise because its a more sporty oriented helmet, almost designed for the chin to be down like it would be on a sports bike in the tuck. I'm thinking that maybe just a rounder helmet would be better suited to my riding position/style of bike.
I probably should have thought of that when buying it, but it was shiny, light and so comfortable! it still is very comfortable and light to be honest and other than the noise a fantastic helmet.
Regarding earplugs I think I will get a cheap pair of foam plugs and see how I go, I don't get paid till the end of the month so it will give me a few weeks to adjust and see if I can get along with them before I find a new helmet.