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General reference information, not medical advice. It does not replace guidance from an audiologist, an occupational health professional or a range safety officer.
Short answer
Gunfire peaks run from about 144 dB SPL (.22 rifle) to 172 dB SPL (.357 revolver), against a 140 dB peak limit set by NIOSH and OSHA. NIOSH recommends double protection (an earplug plus an earmuff) every time a weapon is fired. Electronic protectors add awareness of quiet sounds; in NIOSH testing their peak reduction matched the same devices switched off.
Why gunfire is different from steady noise
Most hearing protection guidance is written for steady noise measured over a shift. Gunfire is an impulse: a very loud peak lasting a fraction of a second. NIOSH recommends that exposure to peak impulsive noise not exceed 140 dB SPL, and OSHA’s limit for impulsive or impact noise is also 140 dB peak, independent of the duration of the impulse (29 CFR 1910.95, Table G-16; OSHA interpretation of 13 August 2018, which quotes OSHA’s earlier position). OSHA sets no limit on the number of impulse exposures. NIOSH measured peaks of 159 to 169 dB for weapons used on an indoor police range, and reverberation in indoor ranges is an additional factor.
The practical consequence is that the figure that matters is how many decibels a device removes from the peak. A label rating built for steady noise, such as the NRR, is not that figure. See how the noise reduction rating works and NRR compared with SNR for the steady-noise ratings.
Passive and electronic (level-dependent) protectors
A passive protector reduces sound by blocking it. An electronic, or level-dependent, protector has a microphone and amplifier that pass quiet sounds such as speech at a comfortable level and limit loud sounds. The related terms people search for describe the same two form factors:
- Electronic earmuffs: a muff with built-in microphones. NIOSH tested level-dependent muffs at unity gain, maximum gain and switched off, and found peak reduction was mostly unaffected by the volume setting because the amplifiers reacted fast enough to give the same protection as when off.
- Electronic earplugs: level-dependent circuits built into pre-molded or custom plugs. NIOSH’s 2007 article states there were no effectiveness data on these at the time, and none on an active level-dependent earplug worn with a passive earmuff.
- Ear plugs for shooting: passive or electronic plugs. Foam plugs are the type NIOSH names for double protection.
The electronics change what the wearer can hear in quiet conditions. They are not a source of extra impulse protection. For the general categories of protector see types of hearing protection.
Earplugs and earmuffs: measured peak reduction
| Protector | Measured peak reduction | Source |
|---|---|---|
| Earplugs | 10 to 30 dB (10 to 28 dB in the 2004 mannequin study) | NIOSH 2007; NIOSH 2004 |
| Standard earmuffs | 20 to 38 dB (25 to 33 dB in the 2004 mannequin study) | NIOSH 2007; NIOSH 2004 |
| Earmuff plus deeply inserted foam earplug | Up to about 50 dB | NIOSH 2007 |
In the 2004 study, which used small-arms fire and an acoustical mannequin, earplugs showed a peak-reduction slope of about 0.2 dB per dB of input and earmuffs about 0.5 dB per dB, so the amount removed depends on how loud the impulse is.
A worked example from NIOSH
For a 12-gauge shotgun, a David Clark Model 27 earmuff reduced the peak from 161 dB to 130 dB SPL, a 31 dB reduction. Adding a deeply inserted foam earplug added about 21 dB. NIOSH’s own formula, N = 10^((140 – peak dB)/10), is described by NIOSH as a conservative estimate that ignores impulse duration and frequency content, and it notes that the audiology, occupational safety and military communities have not reached a consensus on impulse noise and hearing loss risk. The example illustrates why single protection can be marginal for loud firearms; it is not an exposure allowance for any individual.
Double protection
NIOSH recommends that hunters and shooters use double protection every time a weapon is fired, and names a deeply inserted foam earplug with a well-seated earmuff as the combination to use. It notes that care must be taken that the muff stays sealed against the head when safety glasses are worn. OSHA’s interpretation likewise says that where weapons firing exceeds 140 dB, single hearing protection may not be adequate. NIOSH also observes that two passive protectors can compromise communication, and that an electronic level-dependent muff with a foam plug can compensate in some cases.
Where it matters for labs, clinics and supply decisions
Staff in this audience meet the topic when a facility has or neighbors a range, or when hearing protection is specified under an occupational program (see the OSHA PPE standard). The sourced points for a supplier or safety conversation are documentary:
- Is peak-reduction data for impulse noise available for the device, rather than only a steady-noise rating?
- Was the data produced under a stated test method (for example mannequin testing with small-arms fire, as in the NIOSH work)?
- For an electronic device, does the data cover the device with electronics on and off?
Common misunderstandings
- “The NRR tells me everything.” It is a steady-noise rating; the sourced measure for gunfire is peak reduction.
- “Electronic means more protection.” In NIOSH testing, peak reduction was mostly the same with the electronics off or on.
- “One device is enough for any gun.” Peaks reach 172 dB SPL, and NIOSH recommends double protection every time a weapon is fired.
- “Below the limit means safe.” NIOSH notes that peak level is not the sole factor; duration, number of impulses and indoor reverberation also matter.
FAQ
Are ear plugs for shooting enough on their own?
NIOSH measured plug peak reduction of 10 to 30 dB, which is less than many firearm peaks above the 140 dB limit require, and recommends earplugs combined with earmuffs every time a weapon is fired.
Do electronic earmuffs protect better than ordinary earmuffs?
NIOSH found their peak reduction was about the same as with the electronics off. The electronics affect hearing quiet sounds, not the protection against the peak.
What about electronic earplugs?
NIOSH’s 2007 article reports no effectiveness data for level-dependent earplugs at that time. Device-specific impulse test data is the document to look for.
What is the impulse noise limit?
140 dB peak SPL under both NIOSH’s recommendation and OSHA’s rule (29 CFR 1910.95, Table G-16), with no OSHA limit on the number of exposures.
Sources
- NIOSH (Byrne, Franks, Murphy), “Firearms and Hearing Protection,” Hearing Review 14(3), March 2007: https://stacks.cdc.gov/view/cdc/185948 (checked 2026-10-30).
- NIOSH (W. Murphy), “Evaluation of Level-Dependent Hearing Protection Devices for Use with Impulsive Noises,” NHCA Spectrum 21 suppl. 1, 2004: https://stacks.cdc.gov/view/cdc/191027 (checked 2026-10-30).
- OSHA, standard interpretation on the Hearing Conservation Program, 13 August 2018: https://www.osha.gov/laws-regs/standardinterpretations/2018-08-13 (checked 2026-10-30); 29 CFR 1910.95, Table G-16: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.95.
