It’s a good idea to wear earplugs at any speed above 40-50 to protect the ears from wind buffeting. When I’m pootling around town in my three wheeler I don’t worry about it but on a longer journey they’re essential. These are the ones I use:
https://www.alpinehearingprotection.co.uk/collections/motor
My three wheeler is a good deal quieter than the M3W, though…

Tim