Earmuffs

Posted on March 29, 2020

I've heard too much talk about active noise-cancelling headphones. The Wirecutter currently says you probably want the Bose 700, I think you should look at the Bose QC35 II, Sony WH-1000XM3, or Sony WH-H900N... but let's talk about earmuffs in a non-occupational safety and health (OS&H) context instead.

Well, I really just mean earmuffs for survival in the stereotypical evil open-plan office.

These are interesting for various reasons -- potentially cheaper than active noise-cancelling (ANC) headphones, ineffectiveness of ANC on ambient speech, avoiding potential discomfort in the sense of the "ear suck" effect from using noise-cancelling headphones, avoiding potential discomfort/damage from active noise-cancelling...

Ear protection types

There are really two big categories of ear protections: passives, which are what we usually think of as earplugs and earmuffs, and actives, which have passive protections plus some electronics to pick up and safely replay ambient sounds (potentially cutting off loud sounds or compressing them to safe levels).

There are some interesting hybrids that sit between passive and active though:

• some passives earmuffs offer audio from AM/FM radio, 3.5mm input, or Bluetooth, so are basically a cross of regular closed headphones and earmuffs (passive earplugs with audio would essentially be in-ear monitors?)
• some earmuffs have boom mics for Bluetooth radios/phones, or even built-in walkie talkie radios. These typically need to have really good noise-cancellation on the mic to make you intelligible, otherwise there's no point to the mic at all.
• the SureFire Sonic Defenders are passive earplugs that have filters to let normal sound levels through but claim to dampen louder sounds more, and so are definitely passive... but do a little passive action?

Ear protection comes in both earmuff and earplug styles, corresponding to headphones and in-ears, but both have some theoretical upper limits on effectiveness due to sound conduction through bone and soft tissue. The remaining noise levels might need to be masked with some low level of white/brown noise, instead of further isolation

(That raises an interesting idea though -- would it take "less" sound to mask remaining ambient sounds by combining passives with some bone conduction earphones, compared to using passives with regular speakers?)

What makes good ear protection?

There's lots of stuff done around OS&H type of noise exposure, but the problems specific to open-plan offices are a bit different. Instead of loud but continuous machinery hums, even louder impulse noises from gunfire, or wailing babies on planes, we're more likely to be distracted by human speech.

Human speech has consonants above 500 Hz, but more in the 2 kHz to 4 kHz range; most of the range from 1 kHz to 4 kHz is supposed to be important for intelligibility (at least according to this article by DPA Microphones, who do make excellent mics). Therefore, assuming your office soundscape doesn't have any low-frequency hum problems, we might want to value attenuation in that mid-range more than overall performance across the audible spectrum.

Why earmuffs though? Just personal preference, and you may want to look for earplugs instead. I usually don't find earplugs or in-ears comfortable for long periods, though Comply foam tips help a lot -- but given that I've been using wireless headphones recently (since the available wireless in-ears have not exactly been very fantastic), I'm looking primarily at earmuffs, with an eye towards how some white/brown noise can be added in if pure isolation really isn't enough.

(I wrote the above about 3 months ago. I've since succumbed and gotten myself a pair of second-generation Airpods and they actually work pretty well as earbuds. But completely useless at noise isolation on the underground MRT, since they are not the in-ear AirPods Pro.)

Earmuff models

There are lots of models out there, here's a sampling of what's in a reasonable (< SGD 200?) price range.

Passive earmuffs

First the US datasheets are displayed (ANSI S3. 19), then the UK datasheets (EN 352-1). M is the mid-frequency range (500-2k Hz) value that comes with the SNR. For the latter, 500/1k/2k Hz values are the Mean Attenuation in dB.

From the X4 to the X5, there's a significant bump in attenuation around 500 Hz. Comparing the X5 and the Optime 105, the X5 seems to have an edge at 500/1k Hz.

For the Peltor X series, there's the WS-CUSH accessory that goes onto one earmuff and lets you take Bluetooth phone calls. Datasheets don't state which Bluetooth version or profile it supports.

Passive earmuffs with wired audio

Passive earmuffs with Bluetooth audio

These seem few and far between.

Elvex ComConnect runs over USD 100 even on eBay.

There are some very nice-looking 3M Peltor headsets but they run over USD 400 or even double that.

Active earmuffs with amplification

These are meant to pass through voices around you, so they really are counter-productive in an open-plan office.

Random observations from the internet

• Taobao sellers are often describing earmuffs as good for sleeping and studying! The item page visuals even target students.
• Redditors (possibly mostly American?) are discussing using earmuffs for gunfire, and lawn-mowing. As someone who's never had a lawn, that was unexpected.

Review

I decided to max it out and go with the ginormous 3M Peltor X5A, to see what the limits of passive earmuffs are on human speech. I snagged a pair for USD 30.97 on Amazon US, sold by Amazon, and it shipped through ezbuy's Oregon warehouse with no issues. Camelcamelcamel reports that this item goes on sale maybe once a year for below USD 25.

In Singapore, they're going for about SGD 65 from MassTec, and SGD 73.25 (incl GST) from RS Online at qty 1. The 3M Optime 105 goes for much cheaper in Singapore, with prices going down to SGD 38 from some online vendors. If you are constrained to purchasing local, you should consider the Optime 105 instead, especially if you're an office dweller that doesn't care about the headband not being dielectric.

The X5A really has obvious effects once you put it on. If I leave it on for some time, I can hear the low fan whine from the overhead aircon fan unit afterwards. The headband out of the box is rather tight (for good reason), so you'll notice that initially too -- I left it clamped to the width of the box for some time since that's smaller than my head width, and that helped.

How well does it work for human speech?

"Indoor voices" within 2 metres are reduced to a low mostly unintelligible murmur. By indoor voice, I don't mean library whispers, just... what's hopefully regular office speech volumes, of people speaking within a few metres. This is great! It really helps to reduce distraction from discussions in the neighbouring cubicles, when people are using their regular indoor voices.

"Outdoor voices" within 5-10 metres are diminished but still distracting. By outdoor voice, I mean a projected voice, when you're speaking across a room or across a few cubicle rows. It's distracting because the speech is still semi-intelligible. I have not tried inserting earplugs underneath the earmuffs for a few extra dB of noise attenuation, but I suspect this is just beyond the limits of a purely passive approach.

I tried putting my AirPods on under the earmuffs and playing some low level white/pink noise, which pretty much deals with the outdoor voices, but in that case lighter/smaller earmuffs might suffice. The blocker for me is that in one ear, the layout somehow just makes the earmuff interior push uncomfortably against the AirPod, so it's not really a choice.

For now, earmuffs by themselves are still a useful option when I just want some silence without having to drown it out with music. Some particular types of work just don't seem to work well with music at all. I don't use the earmuffs all that often now, but we'll see how that goes once the number of people in the office goes 2x or 3x, and the number of easily accessible meeting rooms tends towards zero.

Final thoughts

I really wish this open-plan office thing with increasing density would go away. Realistically, it seems like the only way away is an all-remote team, and having your own permanent home-office setup -- a part-remote, part-office team is not a great compromise, and I'm not sure whether an x days a week WFH arrangement is a lot better than that.

References

• LiveCollectiva.com's Review of 3M Peltor Earmuffs: Quest for Silence in Singapore (archive.today link) covers the 3M Peltor President, X5A
• RememberEverything's My Top 6 Noise Blocking Earmuffs Review (archive.today link) covers the 3M Peltor X5A, X4A, Optime 105, Optime 98, Optime 95 and Howard Leight Leightning L3
• NoisyWorld.org has several articles:
  • The 5 Best Noise Reduction Earmuffs Review
  • My 5 Favorite Bluetooth Hearing Protection Earmuffs
  • 3M Worktunes Connect Bluetooth Earmuffs Review
  • Howard Leight Sync Stereo Review