Noise under police motorcycle riders’ helmets climbed from 78-90 dB(A) at 30 mph to 114-116 dB(A) at 120 mph in road trials run for the UK Home Office with Hampshire Constabulary (Lower, Hurst and Thomas, Internoise 1996). At 70 mph, that kind of exposure can reach the UK upper action value in 40 minutes, while the NIOSH limit allows only 15 minutes a day at 100 dB(A). A single hour at a steady 80 mph was enough to produce a mean temporary hearing loss of 10.3 dB at 1 kHz in test riders (McCombe et al., Journal of Laryngology and Otology 1995). We aggregated data from NIOSH, OSHA, the UK Health and Safety Executive, NHTSA, the National Law Enforcement Officers Memorial Fund, the World Health Organization, and peer-reviewed studies in the British Journal of Audiology, the Journal of Laryngology and Otology and the Journal of the Royal Society of Medicine. For the broader picture on earplugs and earmuffs, see our hearing protection statistics, and for another emergency-service noise source, our firefighter and EMS siren noise statistics.
TL;DR
- Noise under police riders’ helmets rose from 78-90 dB(A) at 30 mph to 114-116 dB(A) at 120 mph (Lower, Hurst and Thomas, Internoise 1996).
- Wind noise dominated from 40 mph and rose from 90 dB(A) to 112 dB(A) at 100 mph (Binnington et al., British Journal of Audiology 1993).
- At 70 mph a rider can reach the UK upper exposure action value in 40 minutes, and sometimes in 10 (ISVR Consulting, Unusual Sources of Occupational Noise).
- The NIOSH limit allows only 15 minutes a day at 100 dB(A) (NIOSH Science Blog 2016).
- Motorcycle helmets give essentially no attenuation below 250 Hz but about 30 dB at 8 kHz (Młyński et al., International Journal of Occupational Safety and Ergonomics 2009).
- 51% of Brazilian motor patrol officers reported hearing complaints and 36.1% had audiograms suggesting noise-induced hearing loss (de Lima et al., IJOOES 2018).
- One hour at a steady 80 mph produced a mean temporary hearing loss of 10.3 dB at 1 kHz in 18 riders (McCombe et al., Journal of Laryngology and Otology 1995).
- 45% of 44 Grand Prix motorcycle racers had hearing loss greater than expected for age (McCombe and Binnington, British Journal of Sports Medicine 1994).
- Active noise control earmuffs in a helmet attenuated noise by up to 26 dB (Brown and Gordon, The Open Acoustics Journal 2011).
- 186 U.S. law enforcement officers were killed in motorcycle crashes from 1980 to 2015 (NHTSA DOT HS 812 438, 2018).
- 59 Colombian traffic police riders rated a helmet with earpieces at 4.56 on a 5-point safety-improvement scale (Morales et al., Journal of Injury and Violence Research 2024).
1. In-Helmet Noise vs Riding Speed
Speed, not the engine, sets the noise budget of a motor officer. Every major measurement series shows the same curve: levels in the low 90s dB(A) (A-weighted decibels, weighted to match how the human ear hears) at urban arterial speeds, then more than 110 dB(A) at sustained highway pursuit speeds. The rise is steep: in the UK police road trials, in-helmet noise climbed on average 15.5 dB for every doubling of speed above about 55 mph.
For patrol work, the practical meaning is that a long highway assignment and a day of city traffic stops are completely different exposures, even on the same motorcycle and in the same helmet. Town riding stays in a band that occupational limits can tolerate for hours. The open road does not (Ross, Annals of Occupational Hygiene 1989).
| Metric | Value | Source |
|---|---|---|
| On-road noise under police riders’ helmets, from 30 mph (48 km/h) up to 120 mph (193 km/h) | 78-90 dB(A) rising to 114-116 dB(A) | Lower, Hurst and Thomas, Internoise 1996 |
| Average increase in in-helmet noise for each doubling of road speed, above about 55 mph (25 m/s) | 15.5 dB | Lower, Hurst and Thomas, Internoise 1996 |
| Wind noise at the rider’s ear at 60 km/h compared with 160 km/h | About 90 dB(A) vs 110 dB(A) | McCombe, Journal of the Royal Society of Medicine 2003 |
| Wind noise for a helmeted rider, from 40 mph up to 100 mph | 90 dB(A) rising to 112 dB(A) | Binnington et al., British Journal of Audiology 1993 |
| Equivalent continuous noise level during town riding | 63 to 90 dB(A) | Ross, Annals of Occupational Hygiene 1989 |
| Equivalent continuous noise level on the open road | Up to 105 dB(A) | Ross, Annals of Occupational Hygiene 1989 |
| Noise measured on a dummy head at highway speeds with no noise reduction technology | Above 100 dB(A) | Brown and Gordon, The Open Acoustics Journal 2011 |
Context: Most recent available data: the core speed-noise curves come from UK and U.S. studies published between 1989 and 2011 (Binnington et al., British Journal of Audiology 1993). The physics has not changed, but modern patrol motorcycles, fairings and helmets have not been re-measured in a published police-specific study we could find.
2. Wind Buffeting, Windscreens, and Helmet Acoustics
Wind buffeting is the rapid pressure fluctuation created when turbulent air hits the helmet. The UK trials traced the dominant noise source not to air sliding over the shell but to the turbulent wake shed from the top of the windscreen. Where that wake lands, the neck seal or the top of the visor, decides which part of the helmet leaks noise to the ear. The striking consequence: two helmets on the same motorcycle at the same speed differed by roughly 7 to 10 dB, and one helmet that was the quietest behind a low screen became the noisiest behind a higher one.
That finding undercuts any single “quiet helmet” rating. The windscreen height many police riders preferred, a few centimetres below eye level so they could look over the screen, put the turbulent zone right at the top of the visor, at or near the position of maximum noise. The second limit is the helmet itself: it blocks high frequencies well but passes the low-frequency rumble where wind energy concentrates (see the attenuation rows below). All of this starts to dominate at roughly 40 mph, where airflow noise overtakes the machine’s own noise (ISVR Consulting, Noise Levels Under Motorcycle Helmets).
| Metric | Value | Source |
|---|---|---|
| Speed above which airflow noise over the motorcycle, helmet and rider exceeds the motorcycle’s own noise | About 40 mph (65 km/h) | ISVR Consulting, Noise Levels Under Motorcycle Helmets |
| Noise at the rider’s ear in a wind tunnel at air speeds of 80 to 113 km/h (50 to 70 mph) | Approximately 90 to 109 dB(A) | Lower, Hurst and Thomas, Internoise 1996 |
| Difference between helmets tested at the same air speed on the same motorcycle | Roughly 7 to 10 dB | Lower, Hurst and Thomas, Internoise 1996 |
| Noise change from raising the head a few centimetres vs lowering it into the sheltered zone behind the windscreen | 4-5 dB lower vs 8-9 dB lower (some helmets) | Lower, Hurst and Thomas, Internoise 1996 |
| Helmet resonance frequency, and the band where sound energy under the helmet peaks | 250 Hz; 250 to 500 Hz | McCombe, Journal of the Royal Society of Medicine 2003 |
| Noise attenuation provided by motorcycle helmets below 250 Hz | Essentially none | Młyński et al., International Journal of Occupational Safety and Ergonomics 2009 |
| Helmet attenuation at 8 kHz, and its rate of increase above 500 Hz | About 30 dB; 8 to 9 dB per octave | Młyński et al., International Journal of Occupational Safety and Ergonomics 2009 |
Context: the helmet attenuation figures were measured on three helmet models and, as the authors state, do not include noise generated by turbulent wind around the helmet (Młyński et al., International Journal of Occupational Safety and Ergonomics 2009).
3. How Fast Riders Burn Through Daily Noise Limits
Occupational limits are written as a daily budget, and the “exchange rate” (the number of decibels that halves the allowed exposure time) decides how quickly a loud ride spends it. Under the NIOSH 3 dB rule, a full day’s allowable noise dose is used up in 15 minutes at 100 dB(A), a level a rider passes at ordinary highway speeds according to section 1 (NIOSH Science Blog 2016). OSHA’s legal limit is looser, at 90 dBA with a 5 dBA exchange rate (OSHA Occupational Noise Exposure).
In the UK, where the police helmet trials took place, the Control of Noise at Work framework sets action values of 80 and 85 dB(A) and an exposure limit of 87 dB(A) (UK Health and Safety Executive). Measured against the 85 dB(A) upper action value, a motorcyclist at 70 mph will often hit the threshold after just 40 minutes of riding (ISVR Consulting, Unusual Sources of Occupational Noise). For how employers track hearing changes once those limits are crossed, see our OSHA standard threshold shift statistics.
| Metric | Value | Source |
|---|---|---|
| NIOSH recommended exposure limit (8-hour average) and exchange rate | 85 dB(A); 3 dB | NIOSH Science Blog 2016 |
| Time to reach a full daily noise dose under the NIOSH limit at 91, 94 and 97 dB(A) | 2 hours, 60 minutes, 30 minutes | NIOSH Science Blog 2016 |
| Workers who could still develop hearing loss when exposed at the 85 dB(A) NIOSH limit | About 8% | NIOSH Science Blog 2016 |
| OSHA permissible exposure limit (8-hour day) and exchange rate; level that triggers a hearing conservation program in general industry | 90 dBA, 5 dBA; 85 dBA | OSHA Occupational Noise Exposure |
| UK lower action value, upper action value and exposure limit value (daily or weekly average) | 80 dB(A), 85 dB(A), 87 dB(A) | UK Health and Safety Executive, Control of Noise at Work Regulations |
| Riding time at 70 mph before a motorcyclist often reaches the UK upper exposure action value | 40 minutes (10 minutes in some cases) | ISVR Consulting, Unusual Sources of Occupational Noise |
| Riding time at 105 dB(A) that already exceeds the then-recommended 90 dB(A) eight-hour daily maximum | 15 minutes | Ross, Annals of Occupational Hygiene 1989 |
Context: NIOSH estimates about 27 million U.S. workers are exposed to hazardous noise each year (NIOSH Noise and Occupational Hearing Loss), while OSHA’s noise page cites 22 million; see the Data watch note below.
4. Hearing Loss in Police Motorcycle Officers
Direct audiometric data on motor officers is scarce, which makes the only motor-unit dosimetry study we found especially important. In Joao Pessoa, Brazil, the estimated Lex,8h (daily noise exposure normalised to an 8-hour shift) of military police motorcycle officers was 96.9 dB(A), and the daily noise dose (the share of the allowed daily exposure used up) reached 408% over an 8-hour shift and 612% over a 12-hour shift against the Brazilian 85 dB(A) limit (de Lima et al., International Journal of Occupational and Environmental Safety 2018).
The hearing results match the dose. The officers had a mean of 10.5 years of service, and threshold changes at 3,000 and 4,000 Hz correlated with service time (r = 0.458 at 3,000 Hz in the right ear, p = 0.004). Police noise studies outside motor units point in the same direction, though most do not separate riders from other officers (Pollarolo et al., Iranian Journal of Otorhinolaryngology 2022).
| Metric | Value | Source |
|---|---|---|
| Estimated daily noise exposure (Lex,8h) of Brazilian military police motorcycle patrol officers | 96.9 dB(A) | de Lima et al., IJOOES 2018 |
| Daily noise dose vs the Brazilian 85 dB(A) limit, for 8-hour and 12-hour shifts | 408% and 612% | de Lima et al., IJOOES 2018 |
| Motor patrol officers reporting some type of hearing complaint | 51% | de Lima et al., IJOOES 2018 |
| Motor patrol officers whose audiograms suggested noise-induced hearing loss | 36.1% (13 of 36) | de Lima et al., IJOOES 2018 |
| Motor patrol officers reporting tinnitus (ringing in the ears) | 29.8% | de Lima et al., IJOOES 2018 |
| Dutch police motorcycle riders in an early hearing study (Johngepier and Van der Weerd, 1989) | 169 riders aged 26 to 49 | McCombe, Journal of the Royal Society of Medicine 2003 |
| Hearing loss among French police officers vs civil servants (police group included 33 motorcycle officers) | 28% vs 16% | Pollarolo et al., Iranian Journal of Otorhinolaryngology 2022 |
Context: Most recent available data: the Brazilian study (2018) covers a single unit with 36 officers retained after screening, and the paper reports a second, inconsistent split of normal and altered audiograms (see Data watch).
5. Hearing Damage Evidence Across Motorcyclists and Police
Because motor-unit studies are small, the strongest evidence that wind noise damages hearing comes from controlled studies of riders in general. A one-hour run at a steady 80 mph produced a measurable temporary threshold shift (a short-term drop in hearing sensitivity after loud noise), with a mean loss of 10.3 dB at 1 kHz in 18 riders (McCombe et al., Journal of Laryngology and Otology 1995). In the same research program, 246 motorcyclists showed permanent losses beyond what was expected at 0.5 and 1 kHz, the low-frequency range where helmet wind noise concentrates (see section 2).
Professional riders show the cumulative effect: hearing deficit rose with years of racing among Grand Prix competitors (McCombe and Binnington, British Journal of Sports Medicine 1994). A 2025 Istanbul study adds current data from working riders: 31 motorcycle couriers had higher hearing thresholds than 30 controls in the right ear at six frequencies from 500 to 8,000 Hz, and in the left ear at 4,000 and 8,000 Hz (Şahin et al., Archives of Environmental and Occupational Health 2025). The scale of the wider problem is large: the WHO projects that nearly 2.5 billion people will have some degree of hearing loss by 2050 (WHO Deafness and Hearing Loss fact sheet 2026).
| Metric | Value | Source |
|---|---|---|
| Temporary hearing loss after a one-hour test run at a steady 80 mph (18 riders) | Mean 10.3 dB, greatest at 1 kHz | McCombe et al., Journal of Laryngology and Otology 1995 |
| Permanent hearing loss beyond expected levels in 246 motorcyclists compared with controls, at 0.5 kHz and 1 kHz | 3.7 dB and 3.6 dB | McCombe et al., Journal of Laryngology and Otology 1995 |
| Grand Prix motorcycle racers with hearing loss greater than expected for age | 45% (20 of 44) | McCombe and Binnington, British Journal of Sports Medicine 1994 |
| Correlation between hearing deficit and years of racing experience | r = 0.5, P < 0.05 | McCombe and Binnington, British Journal of Sports Medicine 1994 |
| Police officers with noise-induced hearing loss in one reviewed study (365 officers) | 34.2% | Pollarolo et al., Iranian Journal of Otorhinolaryngology 2022 |
| Kathmandu traffic police officers with noise-induced hearing loss (110 officers) | 66.4% | Pollarolo et al., Iranian Journal of Otorhinolaryngology 2022 |
| Surveyed motorcycle riders reporting tinnitus | 46.8% | Brown and Gordon, The Open Acoustics Journal 2011 |
| People worldwide who need rehabilitation for disabling hearing loss | 430 million | WHO Deafness and Hearing Loss fact sheet 2026 |
Context: the Pollarolo review pooled 10 studies with 3,273 participants in total, and only one of them reported a motorcycle subgroup.
6. Earplugs, Active Noise Reduction, and Helmet Fixes
The measured fixes fall into three tiers. Simple helmet sealing work, such as filling the gap above the visor or sealing the neck opening, delivered about 5 to 8 dB. Earplugs and active noise reduction (electronic cancelling of incoming sound) delivered more, and a helmet with active noise control earmuffs cut noise by up to 26 dB (Brown and Gordon, The Open Acoustics Journal 2011). The catch: when the UK team moved its active system from an aviation-style flying helmet into a conventional motorcycle helmet, very little active reduction remained, because the earmuffs need to be isolated from the helmet shell.
Riders clearly want the quieter option. Most UK police forces now issue radio headsets worn under the helmet that also reduce noise (ISVR Consulting, Noise Levels Under Motorcycle Helmets). For why the label rating on an earplug often overstates what a wearer actually gets, see our hearing protection fit-testing statistics.
| Metric | Value | Source |
|---|---|---|
| Foam earplugs: noise inside the ear vs between the plug and the helmet; active noise reduction earmuffs in a flying helmet: drop in A-weighted level | 8 to 16 dB lower; 12 to 13.5 dB lower | Lower, Hurst and Thomas, Internoise 1996 |
| Noise reduction from simple helmet modifications | 5 to 8 dB | ISVR Consulting, Noise Levels Under Motorcycle Helmets |
| Helmet noise attenuation by active noise control earmuffs | Up to 26 dB | Brown and Gordon, The Open Acoustics Journal 2011 |
| Noise reduction reported from earlier helmet modification studies: Dutch handlebar fairing, American, Swedish earmuffs under the helmet | About 6 dB, about 5 dB, about 10 dB | McCombe, Journal of the Royal Society of Medicine 2003 |
| Grand Prix racers who regularly used earplugs | 39% (17 of 44) | McCombe and Binnington, British Journal of Sports Medicine 1994 |
| Surveyed riders who wore earplugs; who wanted a quieter helmet | 63.5%; 95.2% | Brown and Gordon, The Open Acoustics Journal 2011 |
Context: a 2003 medicolegal review concluded that earplugs were the only realistic remedial option for riders, and that no knowledge of their efficacy and safety existed before 1993 (McCombe, Journal of the Royal Society of Medicine 2003). Helmet modifications move levels by single digits; active protection at the ear is what moves them by double digits.
7. Motor Officer Crash Deaths and Situational Awareness
Noise is not only a hearing issue for motor officers: it competes with the sirens, horns and radio traffic they rely on. The crash record shows why that matters. FBI LEOKA data compiled by NHTSA count 186 officers killed in motorcycle crashes from 1980 to 2015, and in fatal crashes on law enforcement motorcycles the first harmful event was a collision with another moving vehicle 82.0% of the time (NHTSA Research Note DOT HS 812 438, 2018).
Better hearing of surrounding traffic is the design goal of the newest helmet research. After two months with a protective helmet fitted with earpieces, 59 Colombian traffic police riders rated their usual helmet as significantly less safe (Z = -3.5, p < .001) (Morales et al., Journal of Injury and Violence Research 2024). On the fatality side, the latest U.S. count shows traffic deaths of officers falling (NLEOMF 2025 End-of-Year Fatality Report).
| Metric | Value | Source |
|---|---|---|
| U.S. law enforcement officers killed in motorcycle crashes, 1980 to 2015 total, and in 2000 to 2009 vs 2010 to 2015 (FBI LEOKA data) | 186 total; 67 vs 31 | NHTSA Research Note DOT HS 812 438, 2018 |
| Occupant deaths on law enforcement motorcycles, 1980 to 2015 (FARS crash data), and share of all law enforcement vehicle occupant deaths | 111; about 11% of 998 | NHTSA Research Note DOT HS 812 438, 2018 |
| Occupants killed on law enforcement motorcycles who were wearing helmets; law enforcement motorcycles with an occupant death that were in emergency use | 92.8%; 36.0% | NHTSA Research Note DOT HS 812 438, 2018 |
| U.S. officers killed in traffic-related incidents, 2025 vs 2024 | 34 vs 44 | NLEOMF 2025 End-of-Year Fatality Report |
| Colombian traffic police riders’ rating of the safety improvement from a helmet with earpieces (4 = safer, 5 = substantially safer) | M = 4.56, SD = 0.54 (59 riders) | Morales et al., Journal of Injury and Violence Research 2024 |
Context: LEOKA counts officers killed, while FARS counts occupants of law enforcement vehicles, so NHTSA warns the two series are not directly comparable. The NLEOMF 2025 total covers all traffic-related deaths (21 crashes and 13 struck-by deaths, meaning officers hit by a vehicle while outside their own) and does not break out motorcycles.
Summary: Police Motorcycle Patrol Helmet Noise and Wind Buffeting by the Numbers
| Metric | Value | Source |
|---|---|---|
| On-road noise under police riders’ helmets, from 30 mph up to 120 mph | 78-90 dB(A) rising to 114-116 dB(A) | Lower, Hurst and Thomas, Internoise 1996 |
| Wind noise at the rider’s ear at 60 km/h compared with 160 km/h | About 90 dB(A) vs 110 dB(A) | McCombe, Journal of the Royal Society of Medicine 2003 |
| Wind noise for a helmeted rider, from 40 mph up to 100 mph | 90 dB(A) rising to 112 dB(A) | Binnington et al., British Journal of Audiology 1993 |
| Equivalent continuous noise level on the open road | Up to 105 dB(A) | Ross, Annals of Occupational Hygiene 1989 |
| Speed above which airflow noise exceeds the motorcycle’s own noise | About 40 mph (65 km/h) | ISVR Consulting, Noise Levels Under Motorcycle Helmets |
| Helmet attenuation below 250 Hz vs at 8 kHz | Essentially none vs about 30 dB | Młyński et al., IJOSE 2009 |
| Riding time at 70 mph before a motorcyclist often reaches the UK upper exposure action value | 40 minutes | ISVR Consulting, Unusual Sources of Occupational Noise |
| Time to a full daily noise dose at 100 dB(A) under the NIOSH limit | 15 minutes | NIOSH Science Blog 2016 |
| OSHA permissible exposure limit (8-hour day) | 90 dBA | OSHA Occupational Noise Exposure |
| Estimated daily noise exposure (Lex,8h) of Brazilian motorcycle patrol officers | 96.9 dB(A) | de Lima et al., IJOOES 2018 |
| Hearing loss among French police officers vs civil servants | 28% vs 16% | Pollarolo et al., Iranian Journal of Otorhinolaryngology 2022 |
| Temporary hearing loss after one hour at a steady 80 mph | Mean 10.3 dB at 1 kHz | McCombe et al., Journal of Laryngology and Otology 1995 |
| Grand Prix racers with hearing loss greater than expected for age | 45% | McCombe and Binnington, British Journal of Sports Medicine 1994 |
| Helmet noise attenuation by active noise control earmuffs | Up to 26 dB | Brown and Gordon, The Open Acoustics Journal 2011 |
| Surveyed motorcycle riders reporting tinnitus | 46.8% | Brown and Gordon, The Open Acoustics Journal 2011 |
| U.S. officers killed in motorcycle crashes, 1980 to 2015 | 186 | NHTSA Research Note DOT HS 812 438, 2018 |
| U.S. officers killed in traffic-related incidents in 2025 | 34 | NLEOMF 2025 End-of-Year Fatality Report |
| People projected to have some degree of hearing loss by 2050 | Nearly 2.5 billion | WHO Deafness and Hearing Loss fact sheet 2026 |
Methodology and Sources
- Lower, Hurst and Thomas, Noise Levels and Noise Reduction Under Motorcycle Helmets, Proceedings of Internoise 96 (1996): wind tunnel and road trials with police riders for the UK Home Office Police Scientific Development Branch.
- ISVR Consulting, Noise Levels Under Motorcycle Helmets and ISVR Consulting, Unusual Sources of Occupational Noise: summaries of the Home Office police motorcycle work and exposure-time estimates.
- McCombe, Hearing Loss in Motorcyclists: Occupational and Medicolegal Aspects, Journal of the Royal Society of Medicine (2003).
- McCombe et al., Hearing Loss and Motorcyclists, Journal of Laryngology and Otology (1995).
- McCombe and Binnington, Hearing Loss in Grand Prix Motorcyclists, British Journal of Sports Medicine (1994).
- Binnington et al., Warning Signal Detection and the Acoustic Environment of the Motorcyclist, British Journal of Audiology (1993).
- Ross, Noise Exposure of Motorcyclists, Annals of Occupational Hygiene (1989).
- Młyński et al., Attenuation of Noise by Motorcycle Safety Helmets, International Journal of Occupational Safety and Ergonomics (2009).
- Brown and Gordon, Motorcycle Helmet Noise and Active Noise Reduction, The Open Acoustics Journal (2011).
- de Lima et al., Audiological Analysis in Military Police Officers With Exposure to Occupational Noise in Motorized Patrol Activity, International Journal of Occupational and Environmental Safety (2018).
- Pollarolo et al., Noise-Induced Hearing Loss in Police Officers: Systematic Review, Iranian Journal of Otorhinolaryngology (2022).
- Şahin et al., Examination of Audiologic Findings and Noise Sensitivity in Motorcycle Couriers, Archives of Environmental and Occupational Health (2025).
- Morales et al., Improving Motorcyclist Safety Through Hearing in All Directions, Journal of Injury and Violence Research (2024).
- NHTSA, Occupant Fatalities in Law Enforcement Vehicles Involved in Motor Vehicle Traffic Crashes, Research Note DOT HS 812 438 (2018).
- National Law Enforcement Officers Memorial Fund, 2025 End-of-Year Fatality Report (2026).
- NIOSH Science Blog, Understanding Noise Exposure Limits: Occupational vs. General Environmental Noise (2016) and NIOSH, Noise and Occupational Hearing Loss.
- OSHA, Occupational Noise Exposure.
- UK Health and Safety Executive, Control of Noise at Work Regulations.
- World Health Organization, Deafness and Hearing Loss fact sheet (March 2026).
- Data watch: the in-helmet noise measurements are old (1989 to 2011) and no published study in our search re-measured current police motorcycles and helmets, so treat them as the most recent available data rather than 2026 values. The speed at which wind noise overtakes machine noise varies by source: 60 to 70 km/h (35 to 45 mph) in the 1996 Home Office trial paper, about 40 mph (65 km/h) on the ISVR summary page, and from 40 mph in the 1993 British Journal of Audiology study. The Brazilian motor patrol paper reports 63.9% normal and 36.1% altered audiograms in one place but 69.4% normal in its results text, so we cite only the 36.1% (13 of 36) split given with counts. NIOSH cites about 27 million U.S. workers exposed to hazardous noise each year, while OSHA’s page cites 22 million. NHTSA’s LEOKA and FARS series measure different things and are not directly comparable, and NLEOMF 2025 figures are preliminary. The Pollarolo review has internal inconsistencies in some table counts.
- Last updated: October 18, 2026. We update this roundup quarterly, and the next refresh is expected when the National Law Enforcement Officers Memorial Fund publishes its 2026 End-of-Year Fatality Report.