Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Why would hearing muffs be tested against continuous and not impulse noise?

+1
−0

Looking at a new pair of earmuffs that a NRR (Noise Reduction Rating) or 34 DB. However the fine print says that said rating is for continous noise and not impulse (like gunfire).

Why would they be tested that way as a big reason people buy earmuffs is to protect their hearing while shooting?

History
Why does this post require moderator attention?
You might want to add some details to your flag.
Why should this post be closed?

0 comment threads

2 answers

+1
−0

Current testing is "is based upon idealized laboratory testing, the NRR can overestimate the protection"

There is some talk about changing the rating system, but in a quick search I don't find anything recent.

Some sources recommend wearing dual protection 'earmuffs and plugs' because the rating on the product, is NOT tested for impulse noises like gun shots.

References

History
Why does this post require moderator attention?
You might want to add some details to your flag.

1 comment thread

General comments (2 comments)
+0
−0

Assuming the ear protector is a linear system, it will attenuate the various frequencies in a pulse the same as it would a steady tone at each frequency.

An impulse is by definition short-lived, and contains a wide spectrum of frequencies. Since the attenuation as a function of frequency varies, there is no easy single number for the attenuation of an impulse. This depends on the frequency content of the impulse.

Even for continuous tones, a single attenuation number is a dumbed-down rating. I haven't looked at standards for hearing protection specs, but that single spec probably implies a particular frequency mix, and the attenuation at different frequencies may be weighed differently. Very likely, different standards agencies have different specs for this too.

It is a lot easier, and results in more reliable numbers, for manufacturers to test sound attenuation devices one frequency at a time. This is probably done with a slow frequency sweep. Surely they have a nice graph internally that shows attenuation as a function of frequency. Simpler specs are then derived from that.

If you had the graph and knew the frequency content of your "impulse", then you could compute some overall attenuation metric for that impulse. However, the next impulse could have a different frequency mix, and therefore a different overall attenuation. Without some definition of a standard impulse (a real mathematical impulse lasts 0 time and contains all frequencies equally), any impulse spec would be meaningless, and not particularly applicable to other impulses anyway.

History
Why does this post require moderator attention?
You might want to add some details to your flag.

0 comment threads

Sign up to answer this question »