Info Relating to Reduction Ratings on Earplugs

Just lately, I've noticed many threads popping up discussing the ratings on earplugs/muffs. I haven't had time - in the last few days - to highlight how these ratings are made, and/or how their accuracy is derived. I've discussed this in detail in the past, so thought it would be better to create a thread with some relevant links.

I was going to post some excerpts, but thought it's probably better to just let you piece it together yourselves.


http://c.ymcdn.com/sites/www.hearin...16_Conference/Presentations/Alberto_Behar.ppt

https://www.etymotic.com/media/publications/erl-0108-2007.pdf

https://www.magidglove.com/nrr_snr_defined.aspx

https://www.shponline.co.uk/hearing-protection-a-how-to-guide-for-those-choosing-ear-defenders/

http://www.hse.gov.uk/foi/internalops/oms/2009/03/om200903app2.pdf


NRR (US) ratings are where most the confusion is derived. It's widely known that these numbers are based on an ideal fit under perfect conditions, so adjustments are often recommended to represent mis-use, bad fits, and factors such as removing the plugs during use (often for conversational purposes). All this can potentially devalue the attenuation, so a standard formula was made to make people aware of what their attenuation might actually be.

 

In relation to the links, if no one wants to sift through, the short story is that the SNR (EU) numbers are much better at showing accuracy. They are tested independently and they make average users fit the plugs themselves (known as subject fit). From this they derive a number which is likely the attenuation for 84% of the population. For the other 16% it's likely to be higher, and this is mostly down to usage. In other words, some people insert and use the plugs better than others, and I'd like to think most T sufferers are part of that 16%.