… and I have to think that the bike you have chosen certainly contributes to the problem, but I’m not going to be ignorant here and say go buy a faster quieter bike, I’ll try to suggest some real world solutions for you.
H-D’s are loud and shake from the get go plus lack any sort of wind streamlining, so even 50 can seem like you are just flying. You speak of ‘us’ & ‘we’ so the assumption is you are riding with other Harley’s ( possibly larger and modified to be grotesquely loud ) and another assumption is; they are leading and you are constantly playing catchup in the wake of a noise that sounds like a space shuttle launch ?
Step one: you need to take the lead position, now their noise ( and yours ) is behind you, you’ll hear your own engine and can focus on going the speed limit ( or slightly faster
Step two: Take the left position instead of the curb position ( while not ideal for safety while riding in numbers ) you won’t feel like you are being driven off the road. Ride the line you would if you were riding solo. Let the riding partners provide your rear echelon traffic interference for a while.
Step three: I personally hate the idea, but ear plugs as recommended by some just might be the ticket, bear in mind that when you have a deficit in one of your senses the others have to make up the difference, so keep those eyes pealed for danger (from ahead and to the sides ), ignore the guys behind other than to make sure they are keeping up once in a while
Step four: get a windshield if you haven’t already, not a big one, just something that dampens the wind buffeting at high speed and keep it tilted back at the top edge so that it actually streamlines a little !
Hope this helps some !