[SAGE] System Administrator Tool chest..

Tue Feb 14 16:18:14 PST 2006

vraptor at employees.org wrote:

>
>
> On Tue, 7 Feb 2006, Richard Chycoski wrote:
>
>> I have a pair of custom molded 'Noise Brakers'. They have a little 
>> valve in them that lets the pressure equalise and makes it possible 
>> to hold a conversation (although not as transparent as noise reducing 
>> headphones, you're right that the latter are useless in a DC).
>>
>> They're not quite as effective as full ear muffs, but they are very 
>> good. They're also translucent and relatively unobtrusive - e.g., if 
>> you want to sleep through a meeting... (:-)
>>
>> Also - remember to relax as much as possible when they're taking the 
>> mold, which involves pouring a compound called 'Audilin' (I think) 
>> into your ear. I had to have one ear redone because of fit, mostly 
>> because I had clenched my jaw too much when the mold was made. It's 
>> not at all painful, just strange to have cold wet molding compound in 
>> your ear...
>
>
> You can get the low-end version of these made for about $50 at any gun 
> show.  They are made of a catalyst/silicon mixture and set up in about
> 10-15 minutes (and you're supposed to wiggle your jaw and swallow 
> while the silicon is setting, Richard ;-).

If you do that with the molding compound they used for the NoiseBrakers, 
you got poorly fitting earplugs. When I went in for the re-mold, they 
told me to relax the muscles in my jaw and around my ears, and the 
second mold was excellent! It may have been that I had clenched my jaw 
too much the first time, and perhaps jaw movement (as opposed to fairly 
continuous clenching :-) would have worked too.

This may work differently with different molding compounds - they used 
'Audilin' for my molds, then sent them to Oregon to build the final 
plugs that contained the valves. I still have them, and they still work 
quite well - 30 years later - although the fit is no longer quite as 
perfect as when I first used them. Apparently ears do grow a little as 
we get older. (:-)

>
> They are quite good if you get them without strings for putting under
> your motorcycle helmet.  You can also go with more high-end versions.
> Some are very similar to the active noise-cancelling ear muffs, only
> an in-ear version.  They can also be built to act as "monitors" for
> radios and other communication systems, or with just your normal 3.5mm
> stereo plug with headphones.
>
> Of late, I've been using silicon-flanged in-ear headphones with my
> iPod (Apple, Sony, Shure, various brands--I have Sony's and Apple's)
> pretty much all the time.  I ride public transit out here on the right
> coast, and these help keep me from going bonkers from the noise/
> people (hazards of being an introvert).  They also are quite useful in
> the datacenter, since companies seem ignore the OSHA requirements for
> ear protection in enviro's above 80-85db.  I guess they get away with
> it because we are (usually) only in there for short periods of time.

Try measuring the noise with 'A' and 'C' weightings - they did this in 
our DC many years ago and although the 'A' weighted noise level was 
within acceptable limits (at the time), the 'C' weighting (basically, 
full spectrum) was through the roof! The problem was that the noise 
components of the disk drives (pre-Winchester technology with *LOTS* of 
hissing air) were mostly at the high end of the spectrum, which 'A' 
weighting ignores. Unfortunately, ear damage doesn't necessarily follow 
an 'A'-weighted (middle of the spectrum) scale. Our managment was kind 
enough to supply the hearing protection even though they weren't 
absolutely required to by the 'letter of the law'.

Radio Shack sells a relatively inexpensive analog sound level meter with 
both 'A' and 'C' weighting, if you want to check out your environment 
(or align your home theatre :-).

>
> I can point people to a number of hearing protection resources if
> there's interest, or email me privately.  I used to make the low-
> end custom molded earplugs on the side.
>
> =Nadine=

- Richard