Nine years of OSHA 1910.95 Injury Tracking Application data make it possible to map occupational hearing loss geographically — by state, by industry concentration, and by year. According to the CDC, approximately 22 million U.S. workers are exposed to hazardous occupational noise annually, but the burden is not distributed evenly: the Midwest manufacturing belt accounts for a disproportionate share of total reported cases, driven by the concentration of automotive, metals, and food processing employment. This analysis breaks down where occupational hearing loss cases are concentrated, what drives the geographic pattern, and what the state-level data means for employers managing WC exposure.
A stamping manufacturer with operations in Michigan and Ohio found that 68% of their hearing loss WC claims over a 10-year period came from those two states — not from their Texas and Tennessee facilities with similar noise profiles. The difference: Michigan and Ohio have more plaintiff-favorable hearing loss WC schedules, and plaintiff attorneys in those states are more experienced with occupational hearing loss cases. State geography affects claim frequency, not just case volume.
The Top 10 States by Hearing Loss Case Volume
The states with the highest total occupational hearing loss case volume in OSHA ITA data are concentrated in the manufacturing belt. Michigan leads all states with approximately 9,842 cases over nine years — more than any other state and nearly double the third-place state. Ohio and Indiana follow, reflecting the dense concentration of automotive, metals, and food processing employment across the Great Lakes region.
The top 10 states by nine-year hearing loss case volume:
| Rank | State | 9-Year Cases | Primary Driver Industry |
|---|---|---|---|
| 1 | Michigan | 9,842 | Automotive manufacturing, fabricated metals |
| 2 | Ohio | 8,890 | Automotive parts, food processing, metals |
| 3 | Indiana | 8,080 | Automotive assembly, steel, food processing |
| 4 | Pennsylvania | 7,320 | Primary metals, fabricated metals, food |
| 5 | Texas | 6,512 | Oil & gas, food processing, general mfg. |
| 6 | Wisconsin | 5,760 | Food processing, paper, fabricated metals |
| 7 | Illinois | 5,000 | Food processing, metals, machinery |
| 8 | Tennessee | 4,342 | Automotive assembly, food processing |
| 9 | North Carolina | 3,980 | Food processing, furniture, textiles |
| 10 | Alabama | 3,620 | Automotive, metals, food processing |
State-level hearing loss data tells you where the concentration is — but it doesn’t tell you what’s driving it at any individual facility. If your state shows up near the top of this list, that’s context for your own program, not a verdict on it.
Why the Midwest Dominates
Three structural factors explain the Midwest’s disproportionate share of occupational hearing loss:
- Automotive manufacturing concentration: Michigan, Ohio, Indiana, and surrounding states are home to the highest concentration of automotive OEM assembly plants and Tier 1–3 supplier facilities in the country. Stamping, welding, machining, and assembly operations in automotive manufacturing produce sustained high-noise exposures for large workforces.
- Metals manufacturing density: The Great Lakes region has historically concentrated primary metals (steel, aluminum) and fabricated metal products manufacturing. Both sectors have hearing loss case rates among the highest in manufacturing.
- Long-tenure workforce: Midwest manufacturing plants tend to have older, longer-tenured workforces than Sunbelt manufacturing. Workers with 20–35 year tenures in the same facility have accumulated larger cumulative noise doses, and their audiograms are more likely to show the 4 kHz notch pattern and threshold progression that triggers WC claims.
Industry Concentration by State
The geographic distribution of hearing loss cases closely maps to the distribution of high-noise manufacturing employment. Key industry-state relationships:
- Michigan: Automotive body, stamping, and powertrain — the sector with the second-highest per-company hearing loss case average in OSHA data. Detroit metro and manufacturing corridor facilities dominate.
- Wisconsin: F&B manufacturing (particularly dairy, grain, and packaged food) combined with paper and fabricated metals creates a state that punches above its population weight in hearing loss cases.
- North Carolina: Furniture manufacturing and food processing drive elevated hearing loss rates despite NC’s smaller manufacturing sector size compared to Midwest states.
- Texas: Broad manufacturing base including oil & gas equipment, food processing, and defense/aerospace. Large absolute workforce produces large absolute case volume even at moderate rates.
WC Claim Implications by State
State-level case concentration has direct implications for WC exposure beyond the raw case numbers:
- Michigan: Has one of the more plaintiff-favorable occupational hearing loss WC schedules. Active plaintiffs’ bar specializing in occupational hearing loss. OSHA ITA data is routinely used in WC proceedings to establish prior knowledge.
- Ohio: Large workers’ comp system with established occupational hearing loss case law. High automotive supplier concentration means many WC claims involve multi-employer prior noise histories.
- Indiana: Growing automotive supplier base with newer workforces in some facilities — but established steel and metals plants with older workforces that are entering the peak WC claim filing window.
- Wisconsin: F&B-driven claims tend to involve long-tenured workers in dairy, grain, and packaged food operations. Seasonal workforce in some operations creates enrollment and record completeness challenges.
What State Data Means for Your Program
For EHS managers and safety directors, the state-level hearing loss data provides two actionable inputs:
- WC exposure calibration: Facilities in Michigan, Ohio, and Indiana should operate with the understanding that they are in states with high case volumes, experienced plaintiffs’ bars, and established WC hearing loss case law. The standard of documentation required to defend a WC claim in these states is higher than in lower-activity states.
- Industry benchmark comparison: The Soundtrace OSHA Hearing Loss Database allows you to filter by state and NAICS code to see how your facility’s hearing loss case rate compares to similarly-situated employers in your state. Being above the state average for your industry is a more meaningful risk signal than being above the national average.
Frequently Asked Questions
Michigan, Ohio, and Indiana lead all states in total OSHA ITA occupational hearing loss cases over nine years. Together they account for more than 40% of national cases, driven by automotive manufacturing, metals processing, and food manufacturing employment concentration.
Automotive manufacturing, fabricated metals, and food processing are concentrated in the Great Lakes manufacturing belt. These are the highest-noise, highest-case industries nationally. Long-tenured workforces with 20–35 year histories in noisy facilities have accumulated large cumulative noise doses that surface as WC claims.
Yes. High-case states like Michigan and Ohio have more experienced plaintiffs’ bars specializing in occupational hearing loss, more established WC case law, and in some cases more plaintiff-favorable hearing loss schedules. Facilities in these states should document their HCP programs to a higher standard.
Know where your company’s hearing loss record stands
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