I thought you were making a joke about earplugs but reading your dealers advice about changing your helmet ......
Because the G310R has no fairing or windscreen you are sitting in the wind and that will give you a steady and Ďregularí noise.
No booming or other noise, just a steady noise from the wind (except when you are riding in a storm)
You have to find out where that noise comes from.
I would suggest to run it onto the right temperature and then open the throttle to 4 or 5000 rpm, standing on the side stand, and listen if something is vibrating or booming (there is another thread on a defect exhaust)
Nothing abnormal too hear, ride it with no earplugs and if possible, no helmet (in first gear) and try to find out if and where the booming noise comes from. Maby you can ask a pal to listen when you pass if he or she hears something strange.
Last but least, try another helmet but I donít think itís the helmet (or you have a 100 year old leather cap 😜
Hope this will help.