The motorcycle safety helmet was first made in 1914. We are overstating the obvious that much has improved in the 118 years since then, as modern helmets such as those from SHOEI are more protective, comfortable and there is one for every type of riding.
However, one issue that has always bugged motorcyclists is wind noise. More specifically, why there is no helmet which is completely quiet even after nearly 12 decades?
The main reason why motorcycle helmets do not seal noises out completely is due to helmet regulations and standards. In this case, ALL helmet standards. Look through the stipulations set by each standard such as for ECE 22.05 above and you will find a clause which says that the helmet must not impede the rider’s hearing in order to pass.
Helmet manufacturers CAN create fully quiet helmets but it is dangerous to the rider.
Yes, you read that correctly.
In other words, a helmet must NOT filter out so much sound and noise that the rider loses his sense of his environment while he is riding. Imagine how dangerous it would be if you did not hear the car which right next to you.
But what are the factors that contribute to wind noise in a helmet?
Type of helmet
The full-face is the quietest among all helmet types simply because there are fewer moving parts. An off-road helmet (for motocross/enduro) is made to provide maximum airflow by taking the slower speeds of off-roading into consideration, thus can be maddeningly noisy at highway speeds.
The helmet's design
No matter how one looks, each helmet needs to overcome air resistance as the motorcycle and rider speeds along. SHOEI has a rig which consists of a robot packed with sensors to monitor head movements (due to turbulence) and noise levels (among other things) inside the helmet. It is through this research that SHOEI helmets have surfaces and aerofoils to make them more stable and also reduce noise levels.
Everyone’s hearing is different
One rider may swear on his mother’s grave that a certain helmet is the quietest, but the next guy feels as if he has his ears glued onto concert speakers when he wears the same helmet.
Everyone’s hearing has different sensitivity, depending on a myriad of factors such as (but not limited to) age, constant exposure to what noise levels (works in a quiet office compared to a construction yard, for example), ear hygiene, inner ear shape, etc. Let us also not forget that everyone has a different head form thus a helmet does not fit two people the same way.
Everyone's head is different
While helmet manufacturers produce helmets of different sizes and fits, everyone's head shape is still different to smaller even larger degrees. This difference results in different fitment of the helmet and can result in varying degrees of wind sound from one wearer to the next. This is true even if the helmet is already fundamentally quieter. This is why SHOEI pays a lot of attention in the SHOEI Personalised Fitment Service (PFS).
Type of motorcycle
This is rather obvious, actually. A naked bike usually offers no wind protection, while a full-dress tourer provides the best protection.
Taking the example of the full-dress tourer, one rider may be taller so his head more exposed to windblast, while a shorter rider may be riding in a windless bubble. Also, one rider may like to ride crouched over the tank a little more, or he lowers his chin and lets the top part of the helmet barge through the airflow.
Comparing to the previous helmet
One may have owned a better insulated helmet prior thus a new one “feels” noisier, or vice versa, thus it is relative.
So, is there a solution?
The only way is to wear earplugs. Foam plugs are useful on the racetrack, but these can be dangerous if worn on public roads. The best way is to wear “smart” earplugs that are specifically designed for motorcyclists. These filter out harmful frequencies such as wind noise but leaves the engine and traffic sounds, and speech through.
Wearing earplugs saves your hearing too.