Sound Masking vs Earplugs

These are usually presented as two answers to one question. They are two tools that work on opposite ends of the spectrum, which is why the right answer is so often both.

They Are Not Competing — They Work at Opposite Ends

Almost every comparison of these two treats them as rival products and picks a winner. That framing hides the only thing that actually decides the question, which is that they do not operate on the same part of the spectrum.

Earplugs remove energy, and they remove far more of it high up than low down. That is not a flaw in a particular product. It is what happens when you put a small compliant object in an ear canal: high frequencies, being short-wavelength, are stopped easily, while long-wavelength low-frequency energy passes through the plug and through the flesh around it.

Masking adds energy, and it can be aimed anywhere you like. Because you choose the sound, you can put its energy exactly where the intrusion is. This is the property neither of the other two has.

Active noise cancellation is the mirror image of earplugs. It works best at low frequencies and falls away higher up, which is why it transforms an aircraft cabin and does little against a conversation at the next table.

Line those up and the practical rule falls out immediately. Household noise that keeps people awake — traffic, machinery, bass through a floor, snoring — is overwhelmingly low-frequency, because that is what buildings fail to stop. Earplugs are weakest precisely there. That is the whole comparison in one sentence, and everything below is detail.

What Earplugs Actually Take Out

The single number printed on a packet is not the useful figure, and knowing why is worth more than any product recommendation.

Attenuation is a curve, not a number. Typical passive earplugs remove considerably less in the low bands than at the top: industry figures put the low frequencies, roughly 125 to 500 Hz, in the region of 15 to 25 dB, against up to about 40 dB at 2 to 4 kHz (Hearing Review). A rating collapses that whole curve into one figure, which is convenient for comparing packets and useless for predicting whether a plug will help against a specific sound.

Ratings are laboratory numbers. They come from careful fitting under test conditions. Real people insert plugs quickly, in the dark, without rolling them down properly, and then lie on them. Real-world attenuation is routinely lower than the printed figure, and the gap is largest for exactly the foam plugs that print the highest numbers, because they depend most on being inserted correctly.

And there is a ceiling no earplug can pass. Sound reaches the inner ear through the bones and tissues of the head as well as through the ear canal, so sealing the canal cannot seal everything. Measurements of that bone-conduction limit put it in the region of 40 to 60 dB across the range from 125 Hz to 8 kHz (Berger, Kieper & Gauger, 2003). Past that point a better earplug stops making any difference at all, and the only remaining options are reducing the sound at its source or masking what gets through.

None of this makes earplugs a bad product. Against high-frequency intrusions — a television, voices, an alarm in an adjacent room — they are excellent and nothing else is as convenient. It makes them the wrong first choice for the sounds most people are actually trying to sleep through.

The Differences That Decide It in Practice

Wearing them for eight hours. This is where earplugs lose most often, and it has nothing to do with acoustics. Side sleepers press the plug against the pillow, which drives it deeper or works it loose over a few hours. Many people wake with sore or tender ear canals. A plug that is perfect for twenty minutes on a plane can be intolerable by four in the morning, and the technique with the best specification is worthless if you take it out at two.

Two people in a bed. Earplugs are a personal device and only help the person wearing them. Masking fills a room, so it works for both people at once — and it also has to be acceptable to both, which is a negotiation worth having while you are both awake.

Hearing what you need to hear. Earplugs reduce everything, including a smoke alarm, a child, or a phone ringing. Masking works on contrast rather than attenuation, so a sound well above the background still gets through; at a correctly set level, an alarm is not affected. If you are the person in the household who has to hear things at night, that difference matters more than any dB figure.

Ear health over months. Nightly use of in-ear devices does not suit everyone, and irritation, and occasionally impacted wax, are common enough reasons people stop. If you get pain, discharge, or a change in hearing, that is a clinician's question rather than a matter of changing brand.

Cost and effort. Foam plugs are consumable and cheap. Moulded ones are neither. Masking, if you already own a phone and any speaker, is free, and the running cost is a little electricity.

What each one cannot do. Earplugs cannot be aimed at a frequency region and cannot pass the bone-conduction ceiling. Masking cannot reduce your exposure — it adds sound to the room rather than removing it — and it handles sudden, unpredictable sounds badly. Both facts are load-bearing, and the masking page covers the second one properly.

Which One, For What

Traffic, machinery, bass from a floor or ceiling, a boiler — masking, with brown noise. All low-frequency, all in the region where earplugs do least, and all continuous enough to mask well. This is the largest category in ordinary homes.

Snoring — both, and expect to need both. Snoring is low-frequency and arrives from a metre away with no wall in its path, which is a bad combination for earplugs and a demanding one for masking. The plugs take out the harmonics, brown noise covers the rasp. The dedicated page covers the setup, and opens with the clinical caveat that belongs on that subject.

Voices, a television, a housemate on a call — earplugs are genuinely good here. Speech sits mainly between about 300 Hz and 3.4 kHz, where attenuation is strong. If you would rather not wear anything, white or green noise covers the same band.

Sudden events — a door, a dog, a car alarm — earplugs, if anything. Masking is poor against sudden sound, because covering the peak means running the masker far louder than the rest of the night needs. Attenuation applies to everything equally and does not have that problem.

Travel — earplugs or cancelling headphones. Neither needs a power socket you may not have, and you are not going to run a speaker in a hotel room shared with someone else.

Tinnitus — neither of the above, and earplugs may make it worse. Removing external sound can make an internal sound more prominent. That subject has its own page, with a franker account of the evidence than this category usually gives.

Why the Combination Beats Either One

It is not a compromise. The two techniques fail in different places, and the places do not overlap.

Earplugs strip out the high frequencies efficiently, which means the masking sound no longer has to cover them — and covering high frequencies is what forces people to run white noise loud. Brown noise then handles the low frequencies that walked straight past the plugs. What you end up with is a lower masking level than masking alone would need, and better low-frequency performance than earplugs alone can reach.

There is a real trade to make consciously. Together they leave you less able to hear an alarm or a child than masking alone would. If that matters in your household, use masking by itself and accept a slightly higher volume. If it does not, the combination is the strongest thing available short of building work.

Set it up in that order. Put the earplugs in first, then set the masking level with them in. Setting the level without them and then adding them leaves you with masking that is louder than it needs to be, all night.

If You Only Read One Paragraph

Earplugs remove far more high-frequency sound than low — roughly 15 to 25 dB in the low bands against up to about 40 dB at 2 to 4 kHz — and no earplug can pass the 40 to 60 dB ceiling imposed by sound reaching the inner ear through bone. Household noise that keeps people awake is overwhelmingly low-frequency, because that is what buildings fail to stop, so earplugs are weakest exactly where the problem is. Masking adds sound instead of removing it and can be aimed at any frequency region, which makes brown noise the better answer for traffic, machinery and snoring; earplugs remain the better answer for speech and for sudden events. Using both beats either, because the failures do not overlap — put the plugs in first, then set the masking level.

Frequently Asked Questions

Related pages

• Sound Masking — Masking does not block sound. It raises the floor so the sound stops standing out — and the colour has to match the intrusion.
• Block Neighbour Noise — Bass and footfall need brown noise. Voices through a wall need white or green. Most advice gives one answer to both.
• Block Out Snoring — Snoring is the hardest sound to mask: low, uneven, and a metre from your head with no wall in the way. What actually helps.
• Block Traffic Noise — Your walls already stripped the top off the traffic outside. That is why brown noise covers it indoors and white noise does not.
• Brown Noise — The deepest colour, measured at −5.98 dB per octave — best for traffic rumble and long overnight sessions.
• Brown Noise App — Which brown noise app to install, whether it is really free, and the five things an installed app does that a browser tab is not allowed to.
• Brown Noise for Tinnitus — Masking versus habituation, why the pitch of your tinnitus decides the colour, and where sound therapy actually sits in the 2014 clinical guideline.
• Brown vs White Noise — The widest gap on the site — 5.98 dB per octave, about 38 dB apart by 8 kHz — and what each colour can and cannot cover as a result.
• White Noise — The flat reference colour, measured at 0.00 dB per octave — the best of the five at making speech unintelligible.
• Green Noise — The mid-frequency colour — a pink base with a broad 500 Hz emphasis, and the only one of the five with no standard definition.
• Brown Noise Machine — Two very different products are sold as a brown noise machine, and one of them cannot make brown noise. What to check before buying.