Re: Ear Plugs

[Barry Schaede <barrys@xxxxxxxxxxxxxxxxxxxxxxx>]

c

On Tue, 28 Feb 1995, Mike Curtis wrote:

> > Can anyone recommend a brand of comfortable ear plugs that attenuate evenly?
> 
> I don't know the brand off hand, but the little foam rubber plugs that 
> you wad up and hold in your ears until they expand are the best I've 
> seen.  They're disposable, but you can use them quite a while before 
> tossing them.
These throw away foam ear plugs do not attenuate evenly.  They are biased 
towards industrial noise .  I'll cite statistics from two different 
brands of off the shelf non custom type throw away earplugs.  One is foam 
and the other is of a soft plastic material and has a neck strap so that 
they can be worn around your neck when temporarily not in use.  I've used 
both of these types for playing music and I was unsatisfied with the 
results due to the attenuation that occurs at different frequencies.
  
Soft Foam Earplugs
125Hz/33.1dB  250Hz/36.3dB  500Hz/36.8dB  1000Hz/38.4dB  2000Hz/38.7dB  
3150Hz/44.1dB  4000Hz/45.9dB  6300Hz/45.4dB  8000Hz/46dB Total NRR 33dB

Soft Silicone type
125Hz/37.3dB  250Hz/38.7dB  500Hz/41.1dB  1000Hz/37.5dB  2000Hz/33.5dB  
3150Hz/39.7dB  4000Hz/40.6dB  6300Hz/46.1dB  8000Hz/47.0dB    NRR 27dB

As you can see the attenuation in these two types of earplugs is far from 
even.  Thes ratings are typical of foam earplugs in general.  the NRR is 
the noise reduction rating and it represents the total average noise 
reduction using an A weighted scale. If the earplug is rated for 27dB NRR 
and you are in a 100 dB noise environment your exposure would be 73dB.  
US Department of Labour regulations list the following noise levels with 
the maximum exposure before hearing damage occurs time intervals.

90dB  8 hrs. per day
92dB  6
95dB  4 
97dB  3
100dB 2
102dB 1.5
105dB 1
110dB.5
115dB.25 or less  
Loud rock music weighs in at 110dB average on an A weighted scale.  We're 
talking permanent hearing damage in a half an hour or less.  Hearing 
damage due to noise exposure is cumulative and irreversible.  You can see 
that from these figures you wouldn't need much of a cut in dB to save 
your ears while playing music.  I only use 15dB earplugs most of the time 
I play.  Mine are custom and expensive.  Their attenuation is flat across 
the audible range and the filters are changeable.  The filters come in 15 
and 25 dB cut.  My earplugs are made by a company called Etymolic 
Research and are available through the people that sell hearing aids.  
Hearing aids BTW start at about 24 times the cost of custom earplugs.  
Harv Andruss mentioned an alternative to full custom earplugs that was 
cheaper than this type.  They are supposed to be evenly attenuated and 
are available from a musicians catalogue that I don't recall the name 
of.  Craig Smoot also wears earplugs when he plays and might have an 
alternative reccommendation of type and brand.  I really do like the flat 
response earplugs I have and reccommnd them for the simple reason that 
when I used throwaway earplugs I didn't wear them often enough because of 
the fact that they were muffly and annoyed me.  I'm sure the foam plugs 
work fine for Mike but the original question was about flat response not 
notched plugs.  Sorry for the lengthy post.  FJM what?