Hi came across this seemingly eye opening information and thought I would share.
The section on the true effect of noise reduction products (How does NRR change decibels of exposure) is the best explanation & most useful i have seen.
It perhaps explains why I and possibly others here often experience spikes despite wearing ear plugs or ear defenders in noisy environments.
Noise Reduction Rating is the metric applied in the US, if memory serves - there's a reference in the link to OSHA, which I understand to be the US equivalent of the Health and Safety Executive.
In the UK noise exposure is calculated via a Single Number Rating, so NRR doesn't apply here - the essential difference is that the figures are measured slightly differently.
There's an explanation of SNR here - alpinehearingprotection.com...
Thanks Pat that’s helpful - do you think the equation they provided below to determine true decibel reduction still applies to SNR?
“take the NRR number (of product in dB), subtract seven, and then divide by two”
Hi Bournville.
It's helpful in that it's an internationally recognized standard and does as much as can be done to set a base level of protection. It would be my understanding that much of the testing which results in these standards is lab-based and not necessarily environmental - so it can never account for the infinite variation in building types, sound system types, machinery noise levels which people are going to encounter when they use hearing protection.
One comment which appears in variations across the SNR/NRR information that I've read is that the NRR figures are felt to be slightly optimistic in how they explain protection levels - I'm sure that trained engineers and sound people are better placed to speak to that than I am.
I definitely get a spike after being at a concert or festival (I use custom fit high SNR plugs) which I’m sure is still related to the general elevated sound compared to my day to day life. Like it says, if the peak can be 150db and maybe the average is 90-110db over a few hours, that’s a lot higher than my usual even with the plugs. But not attending concerts affected my mental health more than I care to imagine so I’m happy to take the occasional spike.
Thank you ! How are you doing with your ears ? I’m trying to ignore it with music and tv. And I’m waiting on the appointment with the specialist. Had some bad days with fibromyalgia.
Hi doing ok thanks, sorry to hear your having a rough time at the moment.
Thank you. Take care ☺️
Pressure pain tintius 
Sleep help with Tinnitus
Severe tinnitus - need help to deal with it 31yo
Tinnitus ad kettle noise 
