Hearing conservation and jobsite noise field guide for concrete crews

What hearing conservation is, and the damage you never feel

Hearing conservation is the set of practices and the written program that keep jobsite noise from taking a worker's hearing. The hard part is that the damage is invisible while it happens. Loud tools and equipment break the hair cells deep in the inner ear, and those cells do not grow back. There is no swelling, no bleeding, no pain in the moment. A worker runs a saw all day, drives home, and never notices anything until years later the high frequencies are simply gone.

Saws, breakers, jackhammers, compressors, generators, and grinders are all loud enough to do it. The loss builds a little at a time, one shift on top of the next, so the worker who got hurt cannot point to the day it happened. By the time conversation gets hard to follow, the cells are already dead.

OSHA approaches this with a threshold and a program. Above an action level near 85 dBA over an 8-hour day, the standard requires a hearing conservation program: measure the noise, control it, protect the ear, test hearing every year, train, and keep the records. The controls that actually work, in order, are quieter tools, distance, enclosure, and then the right hearing protection worn right. The dust this same equipment makes is its own hazard with its own rules, covered in the silica dust control and the concrete cutting and coring guides.

Why noise loss is permanent, painless, and the injury nobody sees

Noise-induced hearing loss is permanent. The inner ear runs on tiny hair cells that turn sound into nerve signals, and loud noise shears them off. Humans do not regrow them. There is no surgery, no medicine, and no hearing aid that brings back what is gone. A hearing aid amplifies what is left. It does not repair the loss.

It is also painless, which is the trap. Cut a finger and you feel it instantly and you protect it. Lose hearing and you feel nothing, so nobody protects against it until the program forces the issue. The worker walks off the job each day feeling fine and the damage is already done.

Tinnitus rides along with it. Many workers with noise damage carry a constant ringing or hissing in the ears that never stops, gets worse in quiet, and wrecks sleep. There is no off switch for it either. Occupational hearing loss is one of the most common work-related injuries in the country, and it is the one with no cast, no scar, and no bad day on the calendar to point to. That is exactly why it gets ignored until it is too late, and exactly why the program matters.

How loud is too loud?

Too loud, as a fast field rule, is when you have to raise your voice to be understood by someone an arm's length away. That rough test puts you in the range where noise can hurt over a full shift. The real answer comes from a measurement, but the arm's-length voice test is the one you can run without a meter.

Noise is measured in A-weighted decibels, written dBA, which weights the sound the way the human ear hears it. The scale is logarithmic, not linear, and that catches people every time. A 3 dB rise is a doubling of sound energy, so 93 dBA carries twice the energy of 90 dBA even though it does not sound twice as loud. Small-looking jumps on the meter are big jumps in dose.

Construction tools run hot on this scale. A circular saw or cut-off saw commonly sits around 100 to 115 dBA at the operator, and a breaker or jackhammer can run higher, often in the 110 to 120 dBA range, depending on the tool, the material, and how close your ear is. Treat those as ballpark figures, not gospel. The actual level depends on the equipment and the task, and the only way to know your number is to measure it. Confirm exposure against OSHA and the AHJ.

What is the OSHA noise action level?

The OSHA action level for noise is an 8-hour time-weighted average near 85 dBA, equal to a 50 percent dose. At or above that level, the employer has to run a hearing conservation program. The action level is the trigger. It is not the point where damage starts and it is not a level you are free to sit at without doing anything.

Above the action level sits the permissible exposure limit, the PEL, near 90 dBA as an 8-hour average. At or above the PEL, OSHA expects feasible engineering or administrative controls to bring the noise down, and where those controls do not get it inside the limit, hearing protection makes up the difference. The general industry rule is 1910.95 and the construction rule is 1926.52, and they line up on the 90 dBA PEL while differing in some of the program detail.

The exchange rate is where OSHA and NIOSH part ways, and it matters. OSHA uses a 5 dB exchange rate, meaning every 5 dB increase cuts the allowed time in half. NIOSH recommends a 3 dB exchange rate and an 85 dBA recommended limit, which is stricter and closer to the physics of equal energy. The 85 action level, the 90 PEL, the 5 dB exchange, and the exact section numbers can shift with the rule and the edition, so confirm the figures that apply against OSHA and the AHJ before you write them on a plan.

Dose and the allowed time at each level

Noise exposure is a dose, not a snapshot. It adds up over the shift, so what matters is the average level across the hours worked, the time-weighted average, combined with how long you spend at each level. Louder means a shorter allowed time, and the time drops fast.

Under the OSHA 5 dB exchange rate, the allowed time roughly halves for every 5 dB. Around 90 dBA the allowed time is about 8 hours. Around 95 dBA it drops to about 4 hours. Around 100 dBA it is down to about 2 hours, and the climb keeps going from there. A worker can blow through a full day's dose in a couple of hours on a loud tool and still have most of the shift left.

The trap is the short, loud task. A two-hour stretch on a breaker can carry as much noise energy as a whole quiet day, and the worker still has six hours to go. Doses add across tasks, so a loud morning and a moderate afternoon both count toward the same daily total. Treat these times as the OSHA framework and verify the exact allowed durations against the adopted standard and the AHJ.

Measuring the noise: sound level meter and dosimeter

You cannot manage a dose you never measured. Estimating from a tool's spec sheet is a starting point, not a number you can stand behind, because the real level depends on the task, the surroundings, the material, and where the ear sits. Measurement is how you find out whether a crew is over the action level.

Two instruments do the work. A sound level meter reads the noise at a point in time, which is good for spot-checking a tool or finding where a loud zone starts and stops. A noise dosimeter clips to the worker and rides the whole shift, integrating the ups and downs into a personal dose and a time-weighted average. For deciding whether someone is over the action level across a real day, the dosimeter is the honest tool, because it follows the worker through every task instead of catching one moment.

Measure when the work changes, not once and forget it. A new tool, a tighter space, a louder generator, or a different material can move the dose. OSHA expects monitoring to identify who is exposed at or above the action level and to be repeated when changes in production, process, or controls could push more workers over. Confirm the monitoring obligation and the calibration expectations against OSHA and the AHJ.

Quieter tools and distance come before earplugs

The order of attack on noise is fixed, and earplugs are last, not first. Engineer the noise down at the source, move people away from it, put a barrier or enclosure between the worker and the source, and only then rely on hearing protection to cover what is left. OSHA's own rule puts feasible engineering and administrative controls ahead of personal protective equipment for a reason: a control at the source protects everyone nearby, while a plug only protects the one ear it is in, and only when it is worn right.

Quieter at the source means a tool engineered to make less noise, a sharp blade instead of a worn one, a muffler that is actually on the equipment, and good maintenance. Distance is free and it works, because sound falls off as you move away, so staging a generator or compressor away from where people stand cuts the dose without buying anything. Administrative controls rotate workers out of the loud task or schedule the loud work when fewer people are around.

Hearing protection is the last layer because it depends entirely on the worker wearing it correctly for the whole exposure. The day a plug is loose, sitting half-in, or pulled out for a phone call, the protection is gone. A quieter tool does not have a bad day. That is why the program leans on the controls first and treats the earplug as the backstop, not the plan.

Earplugs or earmuffs?

Both work when they fit and get worn the whole time, and the better one is the one the worker will actually keep in. Earplugs go in the canal, cost little, fit under a hard hat with no clearance problem, and travel well, but they only protect if they are rolled down and seated deep. Earmuffs cup the whole ear, are faster to put on and take off for intermittent work, and are easy for a supervisor to see at a glance, but they fight with hard hats, glasses, and sweat in the heat.

Each protector carries a noise reduction rating, the NRR, printed on the package as a number of decibels. Higher is more attenuation on paper. The label number is a laboratory result under ideal fit, which is not the jobsite, so the NRR has to be derated before you trust it, covered in the next section.

For the loudest work, doubling up earns its keep. Wearing plugs under muffs on a breaker or close cutting adds protection beyond either one alone, though not by simple addition. The combined protection is roughly the better of the two plus a handful of decibels, not the sum of the two numbers. Reach for double protection on the high-110s and up, and confirm the approach against the manufacturer and the AHJ.

What is NRR, and why you derate it?

NRR is the noise reduction rating, the decibel number on a hearing protector that estimates how much it cuts the noise reaching the ear under ideal laboratory fit. The catch is in that last phrase. The lab gets a perfect seal on a trained subject in a quiet room, and the jobsite gets a tired worker, a quick insertion, and sweat. Real-world protection runs well below the label, so OSHA expects the number to be knocked down before it is credited.

The common OSHA method for an A-weighted exposure is to subtract 7 from the NRR and then halve the result. A plug labeled NRR 29 becomes (29 minus 7) divided by 2, which is 11 dB of real-world protection, not 29. That derated number is what you subtract from the worker's exposure to estimate what the ear actually sees. Take the label at face value and you will think a worker is protected when the ear is still over the limit.

Subtract the derated value from the measured TWA and check the result against the action level. If a worker at 100 dBA wears that NRR 29 plug, the ear is near 89 dBA after the derate, still close to the line and worth a better plug or double protection. The exact derate factor and the weighting can vary, so confirm the method against OSHA and the AHJ, and when in doubt, use the calculation that gives the lower protection.

A loose plug protects nothing

The most expensive earplug in the world does nothing sitting loose in the front of the ear canal. Protection comes from the seal, and the seal comes from the plug being deep and snug, not parked at the entrance. A plug that looks in but is barely seated can lose most of its rated attenuation, which means the worker carries the false comfort of protection with almost none of the actual reduction.

Foam plugs have a method, and it is not optional. Roll the plug down tight and thin between the fingers first, reach over the head with the opposite hand to pull the ear up and back, which straightens the canal, then insert the rolled plug deep and hold it while it expands to fill the canal. If it expands before it is deep, it seals at the opening and protects little. A correctly seated plug makes your own voice sound muffled and boomy from the inside. If it does not, it is not in right.

This is where fit testing earns its place. A fit test measures the attenuation a specific worker actually gets with a specific protector, which turns guesswork into a number and catches the worker who has been wearing plugs wrong for years. Train the insertion, check it, and re-check it, because the loose plug is the single most common reason a crew that wears protection still loses hearing.

Audiometric testing: baseline and annual

Audiometric testing is the hearing exam that tells you whether the program is working or a worker is quietly losing hearing. It is the only part of the program that measures the actual outcome instead of the inputs. Above the action level, OSHA requires it, and it comes in two forms: a baseline and an annual.

The baseline audiogram establishes each worker's starting hearing, taken within a set window after they first go over the action level, commonly within six months, or longer when a mobile testing van is used. It should follow a quiet period away from workplace noise so a temporary shift does not contaminate the baseline. Every annual test after that gets compared back to the baseline to see whether hearing has moved.

The annual audiogram is the early-warning system. A licensed or certified audiologist, otolaryngologist, or other qualified professional reviews the results, and the comparison catches loss while it is small and before the worker has noticed anything. The test is cheap against the cost of a damaged crew and a recordable injury. Confirm the timing, the qualified reviewer, and the recordkeeping against OSHA and the AHJ.

What is a standard threshold shift?

A standard threshold shift, an STS, is a measurable worsening in a worker's hearing compared to the baseline, and it is the alarm bell of the whole program. OSHA defines it as a change in the baseline of an average of 10 dB or more at the 2000, 3000, and 4000 Hz frequencies in either ear, with an age correction allowed. It is the point where the annual test says this person is losing hearing.

An STS is not a paperwork event to file and forget. It triggers action: notify the worker, usually within 21 days, refit or upgrade their hearing protection, retrain them, and re-examine whether the noise controls are doing their job. A persistent STS that meets the recording criteria becomes a recordable injury on the OSHA log. The shift is the signal that the controls or the protection failed for that worker, and the response is to fix it before the loss grows.

The frequencies in the STS definition are no accident. Noise damage hits the high frequencies first, around 3000 to 4000 Hz, which is exactly where the early loss hides, because it does not touch normal conversation yet. Catch the shift there and you can still change the outcome. Wait until the worker complains, and the cells are already gone. Confirm the STS definition, the age correction, and the notification window against OSHA and the AHJ.

Training that sticks

Training is required above the action level, and it works only when it lands as something the worker believes rather than a slide they sat through. The content OSHA wants is the effect of noise on hearing, the purpose and the use of hearing protectors including how to choose, fit, and care for them, and the purpose of audiometric testing. Annual repetition is part of the rule, because the message fades and the crew turns over.

The part that changes behavior is the permanent-and-painless fact. A worker who understands that the ringing in their ears is forever, and that the plug only works seated deep, wears the plug differently than one who was told to wear it because OSHA says so. Show the insertion, have them do it back, and check it. Tie it to their own audiogram and the abstract becomes personal.

Keep the training current and document it. A crew trained once at hire and never again is a crew that has forgotten, and the records are what show the training happened. Confirm the required content and frequency against OSHA and the AHJ.

The written hearing conservation program

Above the action level, OSHA requires a written hearing conservation program, and it is the document that ties the whole effort together. It is not optional paperwork. It is the plan that says how the noise gets measured, how it gets controlled, what hearing protection is provided, how audiometric testing runs, how workers are trained, and how the records are kept.

A program that exists only in someone's head fails the first time that person is off the job or an inspector asks to see it. The written program names the pieces and the responsibilities: who monitors, who reviews the audiograms, what protectors are stocked, when training happens, and where the records live. It is the difference between a crew that happens to wear plugs and a program a contractor can defend.

The trigger is the action level, near 85 dBA over an 8-hour day. At or above it, the full program applies, including the audiometric testing and the training, not just handing out plugs. Confirm the program requirement and its contents against OSHA and the AHJ, and remember that the construction and general industry rules differ in some detail.

Where the noise comes from on a concrete job

Concrete work is loud work, and the same tools that throw silica also throw noise. Knowing which ones cross the action level tells you where to spend the monitoring and the controls.

Saws lead the list. Cut-off saws, wall saws, and slab saws cutting hardened concrete run high, and the operator and anyone close is in the loud zone. Breakers and jackhammers are worse, sitting among the loudest tools on any site. Add the support equipment that runs all day in the background: air compressors feeding the breakers, generators powering the site, vibratory plates compacting subgrade, grinders polishing floors, and powder-actuated tools firing fasteners. None of it is quiet, and a worker can take a damaging dose from the compressor behind them while they think the saw in their hands is the only problem.

The cutting and coring work has its own discipline for the cuts themselves, and the dust those cuts make is controlled under the silica rules. Both the concrete cutting and coring guide and the silica dust control guide cover that side. For noise, the move is the same hierarchy every time: pick the quieter tool, stage the loud equipment away from people, and protect the ears that are still in range.

Impulse and impact noise

Impulse noise is the sudden bang, separate from the steady roar of a running tool, and it has its own ceiling. A powder-actuated fastener firing, a nail gun, a piece of steel dropped on a deck, a hammer on metal: these are short, violent peaks that can damage hearing in a single event, not over a shift.

OSHA sets a peak limit for impulsive or impact noise, commonly cited near 140 dB peak sound pressure level, and that ceiling applies regardless of how short the impulse is or how few of them occur. There is no trading a louder peak for fewer shots. A single peak over the limit is over the limit. The impulse also still counts toward the continuous dose when it is part of the day's noise.

The danger with impulse noise is that the ear has no time to react and the worker often is not wearing protection for a task they think of as quiet between bangs. A powder-actuated tool feels like a single quick job, so the plugs come out, and the peak does the damage. Treat the impulse tasks as protected tasks, and confirm the peak limit against OSHA and the AHJ.

The noise reaches the worker next to the tool

Noise does not stop at the operator. The worker holding the saw is the obvious exposure, but the laborer standing five feet away, the finisher on the next bay, and the spotter behind the breaker are all in the loud field too, and they usually have no protection on because the tool is not in their hands.

This is the exposure that gets missed, because the program tends to think tool by tool and worker by worker instead of zone by zone. A loud tool creates a loud area, and everyone in that area is taking a dose whether they touch the tool or not. The dosimeter on the operator does not measure the bystander, who may be over the action level and completely off the program's radar.

Zone the loud work. Mark the area around a breaker or a saw as a hearing protection zone, keep non-essential people out of it, and make sure anyone who has to be in it is wearing protection. Distance is the cheapest control there is, so the simplest fix is often to move the people who do not need to be close, away from the tool that does not need them there.

Buy quiet and keep it quiet

The cheapest noise control is the one you make at the purchase order. Buying or renting quieter equipment, the buy-quiet approach, cuts the dose for everyone near the tool for the life of the tool, with no daily effort from the crew. When two tools do the same job and one is rated quieter, the quieter one pays back on every shift it runs, especially on equipment that runs all day like compressors and generators.

Maintenance is the other half, and it is the half that slips. A worn blade, a missing or damaged muffler, a loose guard, or a bearing going out all add noise to a tool that left the factory quieter than it is now. Equipment gets louder as it wears, so the same generator that was tolerable new can creep over the line a year later with a tired muffler. Keeping equipment maintained keeps the noise where the manufacturer set it.

Specify the noise rating when you buy, the way you would specify capacity or power. It is a line item that protects hearing without a single plug, and it protects the bystanders the plugs miss. Compare ratings against the manufacturer data and confirm any procurement requirement against the project specification and the AHJ.

What to document

The program lives or dies on its records, because an inspector and a future claim both ask the same question: prove it. Noise monitoring results, audiograms, training, and the protectors provided all need a paper trail, kept for the periods OSHA sets. A program with no records is, for practical purposes, a program that did not happen.

Capture the monitoring data and who was measured, each worker's baseline and annual audiograms with the reviewer's findings, any standard threshold shift and the action taken, the training dates and content, and the hearing protection issued with its NRR. Field software such as the FieldOS tools can hold the monitoring logs, the training records, and the protector assignments in one place so the record is built as the work happens instead of reconstructed later. Confirm the retention periods and the required contents against OSHA and the AHJ.

Common mistakes

• Never monitoring the noise, so nobody knows the dose and the program runs blind.
• Reaching for earplugs first instead of quieter tools, distance, and enclosure that protect everyone nearby.
• Loose or shallow earplugs that look in but seal nothing, so the worker has comfort and no protection.
• No baseline or annual audiogram, so the loss is never caught until the worker complains and the cells are gone.
• Taking the NRR on the label at face value without the OSHA derate, and crediting protection the ear never gets.
• Running no written program above the action level, so the pieces are loose and nothing is defensible.
• Protecting the operator and ignoring the bystanders standing in the same loud zone with no plugs in.
• Pulling protection for impulse tasks like powder-actuated tools because they feel quiet between shots.

Field checklist

Standards and references

The general industry noise rule is OSHA 1910.95, occupational noise exposure, which carries the hearing conservation program, the action level, the audiometric testing, and the standard threshold shift definition. The construction rule is OSHA 1926.52, occupational noise exposure, with its permissible exposure table and the requirement to use feasible controls before personal protective equipment. The two align on the 90 dBA PEL and the 5 dB exchange rate while differing in some program specifics, and construction has long had thinner detail than general industry, so the practical move on a construction job is to build the program to the fuller 1910.95 framework.

NIOSH is the research voice and it leans stricter than OSHA: a recommended exposure limit of 85 dBA and a 3 dB exchange rate, which treats equal energy as equal risk. NIOSH guidance is not the enforced OSHA number, but it is where the science points and it is worth following where you can. The audiogram review belongs to a qualified professional, an audiologist, otolaryngologist, or other physician or technician operating under one, who reads the tests and confirms a shift.

Every number in this guide, the 85 action level, the 90 PEL, the 5 dB exchange, the allowed times, the NRR derate, the STS threshold, the impulse ceiling, and the section numbers, is the OSHA framework as commonly applied, and the details move with the rule and the edition. Confirm the figures and the program requirements that apply to your job against OSHA and the AHJ before you write them on a plan.

Units, terms, and conversions

Noise carries a small vocabulary that shows up across the meter, the protector package, and the standard, and the same idea reads differently depending on where you see it.

Sound level is given in A-weighted decibels, dBA, which weights the measurement toward how the ear hears. Peak impulse noise is given in dB peak sound pressure level. The dose is expressed either as a percentage, where 100 percent is a full allowed exposure, or as an 8-hour time-weighted average in dBA. The decibel scale is logarithmic, so a 3 dB change is a doubling or halving of sound energy. Hearing protector attenuation is the NRR in decibels, which must be derated before it is credited.

dBA

A-weighted decibels, sound level weighted to how the human ear responds to frequency

TWA

Time-weighted average, the noise exposure averaged over an 8-hour shift

Action level

The exposure near 85 dBA over 8 hours that triggers the hearing conservation program

PEL

Permissible exposure limit, near 90 dBA over 8 hours, the OSHA enforced ceiling for the average

Exchange rate

The dB increase that halves the allowed time: 5 dB for OSHA, 3 dB for NIOSH

NRR

Noise reduction rating, the labeled attenuation of a hearing protector, derated before use

STS

Standard threshold shift, a 10 dB average worsening at 2000, 3000, and 4000 Hz from baseline

Dosimeter

A worker-worn meter that integrates noise over the shift into a personal dose and TWA

Related tools

Calculators and readiness checks for this work

Compare your options

FAQ

People also ask

• How do you cut concrete?
• How do you control silica dust when cutting concrete?
• What is a concrete admixture?
• What is the difference between a mechanical and an adhesive anchor?
• What is the difference between integral color and stain?