Can You Hear Me Now? - - - Um, not so well ...

Today's story isn't about protecting corporate crown jewels so much as protecting yourself. Richard's story last month (When Hotel Alarms Sound - https://isc.sans.edu/diary/When+Hotel+Alarms+Sound/15998) got me thinking about personal physical security - in particular, the reader comment about not being able to hear fire alarms inside many datacenters struck a chord - most datacenters are not built with protection of the folks working there in mind. Even when the Health and Safety folks get involved, they'll check for cables across the floor (trip hazards), a first aid kit, clear exits and that's about it.

If you're like me, you spend a LOT of time in datacenters. Small datacenters to large ones, it seems like I'm in a different machine room every day. Over the long haul (30 years and counting), that adds up to a lot of hours! What I'm starting to notice is that some clients are putting signs up regarding noise levels and hearing protection, and some are even providing disposable earplugs.

A quick measurement shows that most larger datacenters are in the greater than 100db-ish range. In fact, even my lab (I have one rack out of 5 in the room) is in that range. This puts a good part of my work environment into the "red zone" for risk of hearing loss.

While this graph is simplistic (it does not account for frequency for instance), you should be concerned about hearing damage after even a short time in most datacenters (in the range of 100db)

What this means to me is that after 30 years, it's about time I started protecting what little of my hearing I've got left. I've been carrying a set of "real" earplugs - the kind that has a real Noise Reduction Rating (25db in this case) in my laptop bag. And like all the personal "critical infrastructure" I carry, I have a spare in the bag, and another in the trunk of my car.

What's really surprised me is that even in the rooms with the signage and dispensers, often I'm the only one wearing earplugs! I am, however, seeing more folks wearing noise-cancelling headphones, which I understand help in much the same way (I am not a doctor, so don't have an actual opinion on how effective these are - especially if you're playing Led Zeppelin or The Black Keys)

While we need an arsenal of technical gear to work, you'll need your ears both during and after work - for the little space it takes in the laptop bag, carrying hearing protection is a good investment. This article isn't meant as a definitive reference, I'd encourage you to do your own research on hearing and other safety issues.

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Rob VandenBrink
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Rob VandenBrink

489 Posts
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Jul 11th 2013
5 years ago

I completely agree. I have a dozen or so of those same earplugs scattered around my office, cars, bags, and house. I use these a lot, so much so that my kids have started asking to use them when things get noisy (they were a hit on the 4th of July). I also use the earplugs and/or over-the-ear muffs when doing work around the house, such as mowing the lawn or working with other power tools.

Sean

4 Posts

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Jul 11th 2013
5 years ago

I use the old used ones as floating heads on bass popping bugs that I tie to go fly fishing for bass. :-)

Moriah

133 Posts

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Jul 11th 2013
5 years ago

You mention: "not being able to hear fire alarms inside many datacenters". I think this means that EARPLUGS would be far safer than NOISE-CANCELLING (a.k.a. Fire-Alarm-cancelling) headphones. If the fire-alarms are hard enough to hear in a datacenter, why make it *impossible* to hear? Use earplugs instead - stay alive in case there is a fire :)

Moriah
12 Posts

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Jul 11th 2013
5 years ago

couldn't agree more, having started out in ops working in an ex-honeywell mainframe machine room, filled with noisy band/line printers in more-or less constant use, ear defenders were a necessity.
could never hear the fire alarm though whenever we had drills and always got into hot water when suggesting flashing lights instead, mutterings about cost, fire break etc
so my question is, HOW DO YOU HEAR A FIRE ALARM in a noisy datacenter, with or without earplugs?
or are you safer staying put, should the worst happen?

Moriah
12 Posts

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Jul 11th 2013
5 years ago

Excellent post. Physical safety is often an overlooked aspect of being in the IT profession. I've unloaded/unpacked/installed many old-school (90's era) Compaq HP Proliant servers that were easily 75+lbs. Traced cables in Datacenters only to trip over unsecured electrical cords. In addition, the air quality in Datacenters is often very poor. There have been various reports about air quality in Datacenters and the air is usually very high in particulate pollutants from electrical fans, etc and not great to breathe for extended periods. Not to mention EMF radiation and yes, potentially dangerous noise levels.

While not as dangerous as working in construction, the IT profession is also not as safe as being an accountant.

da1212

69 Posts

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Jul 11th 2013
5 years ago

Re: "how do you hear a fire alarm"

I've noticed a lot of public buildings have sirens combined with a red strobe light, presumably because a deaf person may not hear the alarm. Probably you would want at least one to be visible from each server aisle.

Steven C.

171 Posts

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Jul 11th 2013
5 years ago

Noise-cancelling headphone will NOT cancel out the sound of a fire alarm. They are designed for constant volume and pitch noise.

Isif

5 Posts

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Jul 11th 2013
5 years ago

The ones i know of are not designed for "constant volume and pitch", though they do work better at low-frequencies (while fire-alarms are usually more at higher frequencies).

http://en.wikipedia.org/wiki/Noise_cancelling_headphones

Isif
12 Posts

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Jul 11th 2013
5 years ago

This is where something mentioned in the article comes in handy: gunshots. Specifically, what shooters wear during the hobby. A lot of advances in noise-cancelling and noise-reduction have been made as a result of that hobby. There are plenty of earplugs that are noise-reducing and noise-filtering (cutting out sounds that go above a certain threshold while at the same time have passive filtering against noise).

Darron Wyke

19 Posts

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Jul 12th 2013
5 years ago