Noise-canceling headphones and hearing protection: what the EPA's NRR label means

Noise-canceling headphones and earmuffs can look alike, but the federal label for hearing protection, the Noise Reduction Rating or NRR, depends on how a product is sold. Under an Environmental Protection Agency rule, 40 CFR Part 211, Subpart B, hearing protective devices made on or after September 27, 1980, must carry the label. The subpart was published on September 28, 1979, and the edition of the federal code revised as of July 1, 2025, still carries it.

The rule defines a hearing protective device as any device or material worn on the head or in the ear canal “that is sold wholly or in part on the basis of its ability to reduce the level of sound entering the ear.” That includes products whose main job is something else but which are “sold partially as providing hearing protection.” The rule text does not mention headphones.

EPA set out how it saw consumer audio products in a 2009 proposal to revise the rule. Products that fit in or over the ears to help with sleep, keep water out while swimming or “enhance the listening quality of music and video dialogue presentations” are “not designed nor intended for the protection of hearing,” it wrote, and so would not be subject to the proposed regulation. But under the proposal, a product sold with “an explicit or implicit claim” that it can protect the user's hearing, or that states its level of sound reduction, would have to be tested and labeled. That explanation came with a proposal EPA has not finalized, so it shows the agency's view in 2009 rather than a rule in force.

What the label must show

Claims beyond the rating need backing too: a maker that wants to make other claims about a device's acoustic effectiveness “must be prepared to demonstrate the validity of such claims,” the rule says. The current text requires the label to be affixed to the device or its carrying case, and to the packaging where needed. Citing changes in selling brought about by the internet, EPA's 2009 proposal would have let some companies that sell only online label electronically, with the label visible to the buyer at the time of sale.

How the number is meant to be used

The information that must come with the device explains the arithmetic: the noise reaching the ear is roughly the A-weighted noise level minus the NRR. Its own example uses a 92 dBA environment, so a protector rated 25 would leave about 67 dBA at the ear (our arithmetic with the rule's formula). For noise dominated by frequencies below 500 Hz, the insert says the C-weighted level should be used instead.

The same insert must warn that improper fit reduces protection, and that the NRR is based on continuous noise and “may not be an accurate indicator” of protection against impulsive noise such as gunfire. The rating already includes an extra 3-decibel reduction to allow for differences in the frequency make-up of workplace noise.

Why lab ratings can run high

In 2009, EPA wrote that the test method the rule relies on, ANSI S3.19-1974, “can result in unrealistically high sound reductions that are generally not attainable in real world use,” which could leave users under-protected. It described how other agencies adjusted for this. OSHA had instructed its inspectors to derate a protector's estimated attenuation by 50%, and NIOSH suggested subtracting 25% of the labeled NRR for earmuffs, 50% for foam earplugs and 70% for other earplugs. EPA noted that both adjustments rest on the agencies' engineering judgment rather than controlled scientific measurement.

Where active noise cancellation fits

By EPA's account, the rule's test method was not built for electronics. In 2009 it said that ANSI S3.19 cannot determine the performance of devices that use active noise reduction, and that manufacturers, NIOSH and the U.S. Air Force had advised it that such devices give their most significant noise reduction at lower frequencies. For active hearing protectors, it proposed a passive rating measured with the electronics switched off, plus an active rating for mainly low-frequency noise, and testing of that kind for any product sold on its active noise reduction.

None of that took effect. The 2025 edition of the federal code still shows Subpart B as published in 1979, with amendments from 1980 and 1982, and our search of the Federal Register on November 12, 2026, found no EPA document using the term after the 2009 proposal. So a pair of noise-canceling headphones without an NRR label has no federal rating to set beside earmuffs or earplugs. How loud headphones themselves play is a separate question, covered by the WHO figures in our headphone volume guide.