As you might imagine, dozens of earplugs are available online. Hundreds. Most are very similar. We built on a selection of top-reviewed contenders from an earlier version of this guide, and then expanded that list to include other well-reviewed plugs on Amazon. We also consulted other websites to get potential names, but very few seemed to have actual reviews of the earplugs beyond “I bought these and they worked,” which is not helpful (because, again, it’s just one person’s ears). Sleep Like The Dead bases its analysis on aggregated customer reviews so is slightly more useful, but that site has narrowed the scope of what it covers down to only five models as of this writing.
After buying all the contenders, we went about testing. This process proved to be harder than we expected, since the existing criteria for testing earplugs are very limited in scope. The American National Standards Institute has established standards for measuring the noise attenuation that hearing-protection devices provide. Researchers make these measurements using tiny microphones inserted into actual humans’ ears. The earplugs then receive a Noise Reduction Rating (NRR) in decibels. The higher the number, the greater the noise attenuation. The greater the attenuation, the quieter the experience you’ll have. The NRR, however, is a technical rating rather than a reflection of what you’ll actually experience; it doesn’t directly tell you the amount of noise attenuation you’ll have. To get a better idea of the real-world noise reduction, you need to subtract 7 from the NRR and then divide by 2. Thus, for example, an earplug with an NRR of 31 decibels actually attenuates noise by 12 dB. This figure doesn’t tell you as much as you might think, though.
Although the ANSI standards are useful—and employed by most manufacturers of hearing-protection devices—they provide only a simple, single-number rating. A single number tells you only how much an earplug or other protection device reduces noise on average, not what part of the sonic spectrum it reduces. For example, airplane-cabin noise occupies a different part of the sonic spectrum than, say, a baby crying. Because no earplug reduces all frequencies equally (that’s impossible), the NRR rating doesn’t provide as comprehensive an analysis of earplug performance as people might like.
So we were curious whether some earplugs might do a better (or worse) job with certain sounds. Would an earplug with a good average NRR but an emphasis on attenuation of bass frequencies be a bad choice for someone wanting to block the sound of conversation? Would an earplug with a lower NRR perhaps be better for our purposes than one with a higher NRR because it attenuates better in the snoring frequencies?
Simulating all sorts of sounds and measuring them with a large number of human subjects wasn’t practical for us, especially because we knew that refining the measurement technique would require many hours of experimentation. Fortunately, just as we were starting work on this article, a newly developed test fixture became available: the G.R.A.S. Sound & Vibration KB5000 anthropometric pinna, attached to the G.R.A.S. 43AG ear and cheek simulator, which has long been a standard for testing earphones and headphones.
Unlike previous pinna simulators, the KB5000 has a realistic ear canal shape; previous simulated pinnae ended in round holes. Thus, the tests we conducted with the KB5000 gave a result closer to what a person with an average-size ear would experience with the earplugs we tried. Using a test fixture instead of live human subjects made it possible for us to experiment with different test signals and conditions until we got consistent and meaningful results.
We connected the 43AG (which is essentially a specialized, high-precision microphone) to an Audiomatica Clio 10 FW audio analyzer and to an M-Audio MobilePre USB interface used with TrueRTA spectrum analyzer software. Then we measured the noise-reduction capabilities of 25 different earplugs.
To measure the effects of the earplugs, we first ran frequency-response measurements. We played unsynchronized pink noise signals (which contain the sound of the entire audio spectrum, from the deepest bass to the highest treble) through four speakers and a subwoofer mounted in the test lab, and used TrueRTA to see how evenly each earplug reduced noise across the whole sonic spectrum. This way, we could see if an earplug was attenuating more bass than treble, or vice versa.
Then we used our own specially created tests to gauge the effectiveness of the earplugs at attenuating various sounds. These sounds included a baby crying (1,000 to 10,000 Hz), a dog barking (250 to 1,300 Hz), a person snoring (50 to 7,000 Hz), traffic noise (70 to 10,000 Hz), airplane-cabin noise (50 to 1,200 Hz), a live rock concert, and an inconsiderate neighbor playing rock music loudly in an adjacent apartment. We used actual samples of the real sounds, edited to allow repeatable, consistent measurements. For example, the crying-baby test signal was a constant (and unbelievably annoying) whine rather than a series of intermittent, unpredictable bursts. We played these test signals at realistic levels and measured the average sound level (or Leq) over 20 seconds to get the attenuation level.
For each of these measurements, we inserted and reinserted the earplugs into the KB5000 pinna simulator at least five times to make sure the fit was good and the earplugs were getting the best possible seal, and thus the best possible performance. Note that the KB5000 represents an average ear, but not necessarily your ear, of course, so your results may vary. We intended these tests to serve as a general guideline only. With few exceptions, the results of our specific sound tests mostly fell in line with those of our initial pink noise blocking test.
After all that was done, four Wirecutter staffers tested the top three performers (the ones that reduced the most noise): Mack’s Slim Fit Soft Foam, Flents Quiet Time, and Howard Leight Laser Lite. In addition, we included the 3M E-A-Rsoft OCS1135, which was rather average in blocking pink noise but was in the top five for blocking plane noises—the 3M earplugs also fit me (a notable rarity). Lastly, we tested a pair of silicone earplugs that some Wirecutter commenters told us they liked.