Wear earplugs. That is the whole answer, and no helmet on the market makes it unnecessary. The US National Institute on Deafness and Other Communication Disorders lists motorcycles and dirt bikes at 80 to 110 dBA and states that long or repeated exposure at or above 85 dBA can cause hearing loss, with the time to damage getting shorter as the level rises. Most of what you hear inside a helmet at motorway speed is not the engine — it is turbulent air separating off the screen, the mirrors and the helmet itself, and it is broadband and constant. A quieter helmet is worth having. It buys you a few decibels; earplugs buy you twenty or more.
Where the noise comes from
Riders who blame the exhaust are looking in the wrong direction. Above about 60 km/h, aerodynamic noise dominates almost everything else.
The mechanism is turbulence. Air separating from an edge — the top of a screen, a mirror stalk, the lip of a chin bar, a badly seated visor — breaks into eddies that fluctuate in pressure. Those pressure fluctuations are sound, and because the source is broadband turbulence rather than a rotating machine, the noise has no clear pitch. It is a wide-spectrum hiss with a strong low-frequency component that penetrates the helmet shell directly.
Two consequences follow. First, aerodynamic noise rises very steeply with speed, so a bike that is comfortable at 90 km/h can be genuinely damaging at 130 km/h. Second, the biggest single variable is usually the motorcycle rather than the helmet. A screen whose top edge sits at helmet height dumps its turbulent wake straight onto your ears, and that is worth far more decibels than the difference between two helmets.
The neck opening is the other main path. Air entering under the helmet travels up inside it and arrives at your ears having already become turbulent. This is why a neck roll that seals well, and a collar or neck tube that closes the gap between jacket and helmet, makes an audible difference at no cost.
What the exposure numbers mean for a rider
The health agencies are consistent about the thresholds, and it is worth reading them directly rather than through a forum.
The NIDCD states that sounds at or below 70 dBA are unlikely to cause hearing loss even after long exposure, that long or repeated exposure at or above 85 dBA can cause hearing loss, and that the louder the sound, the less time it takes for damage to occur. It lists motorcycles and dirt bikes in the 80 to 110 dBA band.
OSHA approaches it as an occupational exposure question: US employers must run a hearing conservation programme when noise exposure reaches 85 dBA as an eight-hour time-weighted average, and engineering or administrative controls are required above 90 dBA on the same basis. Those are workplace limits, not riding limits, but they establish the scale.
Two things about noise-induced hearing loss make it a poor candidate for wait-and-see. It is cumulative, so every unprotected motorway hour adds to a total that never resets. And OSHA notes it is permanent — the damage kills hearing receptor cells in the inner ear and cannot be corrected by surgery or medicine, with hearing aids helping but not restoring normal hearing. The warning sign most riders will recognise is ringing or muffled hearing for an hour or two after a long ride. That temporary threshold shift is the ear telling you the exposure was too high.
Earplugs, and why the wrong ones fail
The commonest complaint is that earplugs make it impossible to hear traffic or a satnav. In practice the opposite is usually true: at speed, wind noise masks everything, and attenuating it lowers the noise floor so that engine note, sirens and voice prompts become clearer. What plugs do remove is a little high-frequency detail, which matters more in town at 30 km/h than on a motorway at 120 km/h.
The second complaint is that they fall out or do nothing. Almost always this is insertion. A rolled foam plug has to be compressed thin, inserted deep into the canal while pulling the outer ear up and back, and then held while it expands. A plug sitting visibly in the outer ear is doing a fraction of its rated attenuation. NIOSH's fitting diagram above shows the geometry.
Three types cover most riders. Disposable foam gives the highest attenuation and the lowest cost, and is the right starting point. Reusable flanged plugs are easier to insert consistently and easier to remove with gloves on, at slightly lower attenuation. Custom-moulded plugs, made from an impression of your ear canal, are the most comfortable over long days and the most expensive; filtered versions attenuate more evenly across frequencies rather than cutting the treble hardest.
Two cautions. Check the law where you ride — a small number of jurisdictions restrict or prohibit earplugs for riders, and rules on in-ear devices vary. And never use earplugs to make a loud helmet speaker tolerable; that combination pushes the level at your eardrum higher, not lower.
Where the decibels are
| Change | Cost | Effect on perceived noise | Notes |
|---|---|---|---|
| Correctly inserted foam earplugs | Negligible | Largest single reduction available | Attenuation depends entirely on insertion depth |
| Adjusting screen height so the wake misses your helmet | Free to moderate | Large | Test by ducking 10 cm at motorway speed |
| Closing the gap at the neck with a tube or collar | Low | Moderate | Blocks the air path up inside the helmet |
| Riding with the visor fully closed and correctly seated | Free | Moderate | A visor cracked open is one of the loudest things you can do |
| Buying a quieter helmet of the correct size | High | Small to moderate | Fit matters more than model; a loose helmet leaks air |
| Closing crown vents | Free | Small | Trades directly against cooling |
| Removing an aftermarket spoiler or camera mount | Free | Small | Any protrusion is a turbulence source |
| Quieter exhaust | High | Very small at speed | Aerodynamic noise dominates above about 60 km/h |
Choosing and setting up for quiet
Fit is the first control. A helmet that is slightly too large leaks air at the neck roll and around the visor seal, and it moves relative to your head under aerodynamic load, which generates its own noise. The shop test sequence is in helmet sizing and head shape, and it does more for noise than reading reviews does.
Type is the second. Every opening is both a cooling path and a noise path, which is the tension running through helmet ventilation. Modulars are typically the noisiest closed type because the chin bar joint adds seams, and open faces are noisier still but let you hear the world more naturally at low speed. The full picture is in helmet types explained.
Audio is the third, and it is where riders quietly damage their hearing. If you run intercom speakers to hear navigation, the temptation is to raise the volume until the prompts beat the wind noise. That means the level at your eardrum is above an already harmful background. Earplugs plus a lower speaker volume is better than no plugs and a high volume; better still is not needing the audio at all, which is the argument for putting turn-by-turn guidance on a handlebar display you can glance at and keeping the helmet audio for calls. Speaker placement matters too, because a speaker sitting off the ear canal gets turned up to compensate — see Bluetooth headset fit.
Finally, treat persistent ringing, muffled hearing lasting more than a few hours, or any noticeable change in one ear as a medical matter rather than an equipment one. The World Health Organization's fact sheet on deafness and hearing loss is a reasonable starting point, but a hearing test from an audiologist is the actual answer, and a baseline test while your hearing is still good is worth more than any amount of guessing later.
Frequently asked questions
How loud is it inside a motorcycle helmet?
It varies enormously with speed, screen, helmet and fit, which is why single numbers quoted online are unreliable. The NIDCD places motorcycles and dirt bikes in the 80 to 110 dBA range, and states that long or repeated exposure at or above 85 dBA can cause hearing loss. Measure your own with a sound level meter app if you want a figure for your bike.
Is it safe to ride with earplugs?
For most riders in most places, yes, and at speed it usually improves your ability to hear sirens and horns by lowering the wind noise floor that was masking them. Check local law before you rely on it, since a few jurisdictions restrict earplugs or in-ear devices for riders.
Which is quieter, a full face or a modular?
A full face, generally. A modular carries a hinge and a chin bar joint, which adds seams and paths for air, and the extra hardware makes a tight seal harder to achieve. The difference is smaller than the difference between a well-fitting and a slightly loose helmet of either type.
Will a quieter helmet let me stop using earplugs?
No. The gap between a noisy helmet and a quiet one is a few decibels; correctly inserted foam earplugs attenuate by an order more than that. Treat helmet choice and hearing protection as separate decisions.
My ears ring after a long ride. Is that a problem?
It is a temporary threshold shift and it means the exposure was high enough to affect the inner ear. Repeated episodes are associated with permanent damage, which OSHA notes cannot be corrected by surgery or medicine. Start wearing plugs on every ride and get a hearing test.
