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0.31% average injury rate. That number looks manageable. It is not. When you apply it to a workforce of 3.86 million people across 811 companies, you get 11,892 occupational hearing loss cases — the second-highest total of any industry in America. Transportation Equipment Manufacturing’s hearing loss problem is hiding behind an average that flatters the industry. Here is what the data actually shows.
Soundtrace analyzed nine years of OSHA ITA hearing loss data across 21,120 U.S. establishments. Transportation Equipment Manufacturing — which includes automotive assembly, aerospace, rail, and shipbuilding — ranks #2 nationally by total case volume. This is the industry-specific companion to our industry rate analysis, Food & Beverage deep dive, and national trend overview.
A 0.31% hearing loss injury rate sounds like a success story. Compared to Food & Beverage Manufacturing at 1.42%, or Wood Products at over 3%, it looks positively safe. It is not. What that rate tells you is that Transportation Equipment manufacturers have, on average, done a better-than-median job of protecting individual workers. What it does not tell you is what happens when you multiply even a low rate across one of the largest manufacturing workforces in the country.
3.86 million employees. 0.31% rate. That math produces nearly 12,000 hearing loss cases over nine years — or roughly 1,300 per year, every year, at the industry level.
That 14.7 cases per company is the number that should stop every EHS director in this sector cold. It is higher than Food & Beverage (13.3), higher than Fabricated Metal, higher than every other major industry in the dataset. It means the average Transportation Equipment manufacturer — at a rate that seems modest — is still recording more than one and a half hearing loss cases per year, year after year.
For large automotive OEMs and tier-1 suppliers with thousands of employees, the per-company figure can be orders of magnitude higher than the industry average. The dataset includes companies logging 2,389 cases over nine years at a single reporting entity — roughly 265 hearing loss cases per year.
A below-average injury rate in a massive-workforce industry is not a clean bill of health. It is a volume problem wearing a rate disguise. Transportation Equipment manufacturers who point to their 0.31% rate as evidence that the problem is under control are measuring the wrong thing.
Transportation Equipment Manufacturing is not one industry. It is five or six distinct noise environments that happen to share a NAICS classification. Automotive assembly, aerospace fabrication, railcar manufacturing, shipbuilding, and motorcycle and recreational vehicle production each have their own noise signature — and each presents different hearing conservation challenges.
The stamping press is the signature exposure of automotive manufacturing. A progressive die press stamping body panels operates at impact noise levels that can peak above 130 dB with a repetition rate of dozens of cycles per minute. Workers in stamping plants accumulate more noise dose in a single shift than many workers in other heavy industries accumulate in a week. OSHA’s 5 dB exchange rate means that every 5 dB above the 90 dBA PEL cuts the permissible exposure time in half. At 105 dBA, the permissible exposure without hearing protection is one hour per day.
At noise exposures above 100 dBA, hearing protection alone is not an adequate long-term control strategy. OSHA requires feasible engineering and administrative controls before relying solely on HPDs. In stamping operations that have operated at these levels for decades, the documented absence of engineering controls is both a compliance gap and a significant workers’ compensation liability.
Transportation Equipment’s trend line mirrors the national pattern but at a scale that makes every inflection point consequential. The pre-pandemic growth, the 2020 detection gap, the post-2020 surge, and the 2024 partial-year trajectory tracking toward a new peak all follow the same arc — amplified by workforce size.
Note the shape of the 2020 dip: Transportation Equipment saw one of the steeper single-year drops in the dataset, reflecting the severity of automotive production shutdowns in spring 2020. Many assembly plants went to zero production for 6–8 weeks. But unlike industries where workforce reductions were permanent, Transportation Equipment came back at full scale — bringing with it the full noise exposure burden and deferred audiometric testing backlog that drove the 2022–2023 surge.
Grouping all of Transportation Equipment Manufacturing into a single category obscures the fact that the hearing conservation challenge is fundamentally different depending on the subsector.
| Subsector | Primary Noise Sources | Key HCP Challenge | Typical Workforce Size |
|---|---|---|---|
| Automotive OEM Assembly | Stamping, welding, air tools, conveyance | Scale and enrollment completeness | 1,000–10,000+ per facility |
| Tier-1 Automotive Supply | Metal forming, stamping, painting | Multi-site consistency, contractor workers | 100–2,000 per facility |
| Aerospace Fabrication | Riveting, drilling, grinding, composite work | Extreme exposure levels, long career tenure | 200–5,000 per facility |
| Shipbuilding & Marine | Plate grinding, welding, blasting, enclosed spaces | Confined-space noise amplification | 500–5,000 per facility |
| Rail & Transit Equipment | Metal fabrication, welding, grinding | Mixed workforce, maintenance exposure | 100–2,000 per facility |
This subsector variation has a direct implication for hearing conservation program design. A program template built around an automotive assembly model — large enrollment, annual cycle management, STS tracking at volume — is structurally mismatched to an aerospace facility where the priority is identifying and managing workers with extreme individual exposures. Both need strong programs. They need different programs.
The 0.31% average injury rate suggests that Transportation Equipment manufacturers have invested more in hearing conservation than many other sectors. That is almost certainly true for large OEMs with mature EHS departments and union-negotiated safety programs. It is considerably less true for mid-sized tier-1 and tier-2 suppliers, where the compliance gaps look much closer to the patterns we see in other high-volume industries.
Large automotive and aerospace manufacturers operate across dozens or hundreds of facilities. Noise profiles, equipment configurations, and worker populations vary significantly across sites. Programs that are strong at one facility are often poorly replicated at others — particularly at acquired facilities, joint ventures, and locations in states with less active OSHA enforcement. The 300 Log consequences of program inconsistency accumulate at the corporate level in ways that facility-level metrics obscure.
Transportation Equipment manufacturing makes extensive use of contract labor, temporary workers, and staffing agency employees. OSHA’s hearing conservation standard applies to employers based on workplace noise exposure — the host employer has responsibility for workers whose activities expose them to noise at or above 85 dBA TWA, regardless of who issues their paycheck. In practice, contract workers at automotive and aerospace facilities are frequently not enrolled in hearing conservation programs, representing a significant compliance gap and an undercount in the ITA data.
At noise levels above 100 dBA, the attenuation adequacy math changes. A standard disposable foam earplug with a labeled NRR of 33 dB — de-rated to roughly 16 dB using OSHA’s Appendix B method — brings a 105 dBA exposure to approximately 89 dBA. That is technically above OSHA’s PEL. Stamping workers wearing standard earplugs in facilities where press noise peaks at 110–115 dBA are receiving inadequate protection even when they wear HPDs correctly. The program’s hearing protection selection methodology is a compliance issue, not just an engineering one.
Aerospace manufacturing workforces are characterized by long career tenure — workers who have spent 20, 25, or 30 years in the same high-noise roles. These workers arrive at audiometric testing sessions with pre-existing threshold shifts that have accumulated across entire careers. Baseline audiogram quality — whether it was established before career noise exposure began, or years into high-level exposure — has enormous implications for STS calculation, work-relatedness determination, and workers’ compensation liability. Many aerospace facilities are managing hearing conservation programs for workers whose baselines reflect decades of already-accumulated damage.
Transportation Equipment’s hearing conservation challenge is fundamentally a program administration and consistency problem, not a knowledge or awareness problem. Large companies in this sector know they have noise. The failure points are in execution — enrollment completeness, testing cycle management, STS follow-up, and multi-site consistency.
Soundtrace provides in-house audiometric testing equipment, automated STS detection with real-time flagging, cloud-based recordkeeping that travels with workers across facilities, and medical oversight — designed for the scale and complexity of Transportation Equipment manufacturing operations.
Get a Free QuoteWatch a DemoA 0.31% rate applied to 3.86 million employees produces nearly 12,000 cases over nine years. The industry’s scale means even a below-average per-worker rate generates an enormous absolute case volume. The 14.7 cases-per-company average — the highest of any major industry in the dataset — is the more meaningful figure for individual company benchmarking.
Metal stamping and press operations in automotive manufacturing regularly exceed 100 dBA with impact peaks above 130 dB. Aerospace riveting and pneumatic drilling typically runs 95–115 dBA. Both sectors involve grinding, welding, and assembly operations generating sustained exposures well above OSHA’s 85 dBA action level.
Yes. OSHA’s hearing conservation standard covers workers based on noise exposure in the workplace, not employment classification. Host employers have a responsibility to ensure that contract and temporary workers exposed at or above 85 dBA TWA are enrolled in a hearing conservation program, regardless of who employs them.
Automotive manufacturers face a scale challenge: large hourly workforces, high turnover in some roles, and multi-shift operations requiring consistent enrollment and testing across thousands of workers. Aerospace manufacturers face an intensity challenge: smaller workforces but extreme exposures in riveting and fabrication operations, combined with long career tenure that accumulates damage over decades.
Soundtrace provides in-house audiometric testing equipment, automated STS detection with real-time flagging, cloud-based audiogram management that tracks workers across facilities, and medical oversight — built for multi-plant manufacturers managing large hourly workforces across multiple shifts and locations.