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Hearing Protection Measurements

Jdunk54nl

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#1
Hey All,

I had a brief chat with Amir about testing out some hearing protection on his headphone rig.

He showed us that he can measure IEM's now, so hearing protection should be doable as well. He could measure a set of headphones, put in the hearing protection and re-measure to see the changes.

Some claim to be fairly level attenuation without changing the way we hear.

Example: Etymotic 20xs hearing protection:
https://www.etymotic.com/consumer/hearing-protection/er20xs-uf.html

1619991957918.png



Amir said he has the etymotic's but would be willing to test others as long as they are sent to him. I am willing to send him some to see the results, but not 100% sure what others have tried and had good results with. I don't want to waste money on "hifi" hearing protection that we know isn't good.


Some other's claiming to be hi-fidelity:

Hearos High Fidelity musicians ear plugs.
https://hearos.com/collections/music/products/earplugs-high-fidelity-series-with-free-case

Eargasm:
https://eargasm.com/products/eargasm-high-fidelity-earplugs?variant=31896608833609

Earasers (the only other one besides etymotic that posts graphs and a study done by Virgina Tech: https://www.earasers.net/pages/specifications)
https://www.earasers.net/collections/musicians-hifi-earplugs/products/starter-kit
1619992409879.png
 

Bob-23

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#3

RayDunzl

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Jdunk54nl

Jdunk54nl

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Thread Starter #6
"3M Peltor Optime III"

I like these very much. Good protection. Even though clamping pressure is relatively high, they are quite comfortable due to the very soft cushions.

After having had quite a bad infection of one of my ears, some years ago, I stopped putting anything into my ear-canal.

https://www.amazon.de/3M-Peltor-Optime-Kapselgehörschutz-schwarz-rot/dp/B000VDX18E/ref=pd_sbs_1

Ya, in ear style is what he would be able to really measure and see how it changes the frequency response. Hearing protection like the above is awesome for hearing protection when you need to remove/put on all the time. I use something simliar, with bluetooth, when I am doing things around the house where I don't need to hear things well.

I use in ear all the time on my motorcycle, rzr, etc. Cheap foam plugs make it so I can't use my com system for communication or audio. The etymotics (the only ones I have personally tried because they worked well) actually cut the wind but I can still hear the audio fine. My rzr has a custom tuned stereo and it would suck not to be able to use it and hear it like it is supposed to be, but I also want to protect my ears.

My wife and I also like to go to concerts, but I wear hearing protection there as well. Again cheap foam plugs don't seem to work well and the etymotic are way better, but it would be interesting to know just how much they do change the frequency response.
 

Beershaun

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#8
I've used the Eargasm plugs at concerts and was happy with the experience. E.G. could hear the concert well without my ears ringing afterward.
https://smile.amazon.com/gp/product/B079H3ZV24/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

They claim:
  • Up to a 21 dB drop in Noise Levels (NRR 16 dB)
"Eargasm Earplugs reduce noise levels proportionally while maintaining sound integrity. It is like having your own volume knob for life! You hear everything, but at safe and enjoyable levels. At the heart of each ear plug is an attenuation filter. These filters reduce noise to safe levels while preserving clarity of speech and richness of music. Sounds are reproduced exactly as your ear would hear them but at a reasonable volume."

Some thoughts:
1) First understand the claim the companies are making in terms of dB of attenuation, frequency range of attenuation or other claim about maintaining fidelity. How to convert the claims to measurements against a spec.

2) Find out the target curve we should use to measure against based on hearing damage research? Is there a curve (maybe it looks something like the Fletcher Munson curve) showing the max SPLs across the full frequency band (not just a-weighted) that can be sustained for 2-4hours without damage to our hearing? Per Amir's recent video on SPL I think we would need something designed with music in mind and not OSHA work safety standards since those standards tend to be a much narrower frequency band related to mechanical and background noise.
3) Then run a test tone (like pink noise or something) across that frequency range at some set SPL at xdB (the amount of attenuation claimed by the manufacturer) above the safety standard to see if the plugs attenuate the signal as claimed and across what frequency range and what that attenuation curve looks like. Overlay that on the target safety max curve to see how many decibels of attenuation across what frequency range and if the test "concert" would result in hearing damage or not.
4)Then lastly is there a attenuation preference curve to target to maintain the relative fidelity of music so it's enjoyable to the listener and not colored by the plugs. E.G. like the harman slope for speakers of -0.5db/octave. How closely does the earplug maintain that curve keeping below the safety SPL safety limits.
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #9
I think the ideal curve for earplugs would be literally the original curve (of whatever was measured) only attenuated. As in 0 change to that curve just lower dB's. That would be the whole point of these hi-fidelity ear plugs, or at least what they claim.

I don't really care about how much they attenuate (this is good to know) but I want something that attenuates x number of dB's based on their claim, but leaves the frequency response the same (or as close to it) as original.
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #10
Take this headphone that was just measured:
1620060536008.png



If you were to place some in ear hearing protection in between this headphone and your ears, ideally those green and red curves would just drop by ~20dB's and no other change. Similar to just turning the headphone volume down by 20db's. The curve should remain the same (I hope).

If there is any change to the green and red curve, then that is how the hearing protection is changing how we hear and "coloring" the sound. No coloring would be ideal, just like anything in audio, we want to hear the original as best as possible without the items we are using having influence (other than attenuation in this case)
 

Wolf

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#11
I've used a lot of earplugs in my time working in factories, and actually using them correctly. Proper usage of (foam; rolling) them and insertion into the canal is paramount.
Some observations-
- channel caps do not work. Mack's pillow soft.
- 'tree' style are for sudden loudness, and not for consistent loud noise.
- tapered plugs were somewhat difficult to get a good seal in my 'larger' ear-holes.
- cylindrical expanding foam plugs seemed to seal the best. EAR/Decidamp.
- different foams are superior to others.

What worked really well for me ended up being the Quiet Time brand from Wallie World. If I want really good protection, Quiet Time under the Peltor muffs really do the job.

And one more thing- the damping in the Peltor muffs being an open-cell-foam can be improved. I've added Ultratouch to my Peltor muffs under the foam, and cut down their cavity resonance quite impressively.
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #12
I think some are missing the point of this thread.

This isn't really about how well these products will help protect your hearing, this is more of the hi fidelity in ear plugs and how they impact the frequency response we would ultimately hear. For concerts or other audio times when you want to lower the level but do not have control of it.

A couple products suggested aren't claiming to be "hi fidelity" ear plugs. They are claiming to be good hearing protection but most of these sacrifice frequency response. They also aren't IN EAR CANAL type of hearing protection.


I have some really good hearing protection for shooting and using gas powered yard tools. However, that isn't the subject here.

The subject here to investigate is: How does the "hi fidelity" or "Musicians" hearing protection actually do on ONLY attenuating sound and not changing the frequency response?
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #14
My apologies. I misunderstood your intentions.
No worries, you aren't the only one, I will blame myself for not being clear enough in the OP. Usually that is the issue when multiple people are answering the "wrong" question. It isn't them, it is me.
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #15
The subject here to investigate is: How does the "hi fidelity" or "Musicians" hearing protection actually do on ONLY attenuating sound and not changing the frequency response?

The manufacturers claim to be making their in ear canal hearing protection very similar to the human ear canal and therefore to have minimal impact on frequency response and only attenuate the sound to lower volumes.
 

Helicopter

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#16
I can relate to @Wolf with factories, rolling 33NRR foam, and the 30NRR Peltor muffs on top. Last time I went to a concert I didn't even know about hifi plugs and wore 33NRR foam. I would never wear muffs to a concert. Next time I go to a (potentially loud) concert, I will be packing some hifi plugs.

Seems it might be best to EQ some good closed phones for sweep tests into the GRAS with the plugs in. You might want to do some calibration sweeps to get the EQ right for measurement. Probably closed planars would be about perfect.

I would be curious how the 33NRR foam stacks up to the hifi options. I would be willing to drop ship some reasonably priced hifi plugs to Amir if we found some consensus on what looks most promising.
 

dougi

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#17
I think some of the non hifi tri-tip hearing protection ones (such as 3M E-A-R Ultrafit) would be a good comparison against the Etys. I get my daughter to use the latter when practising flute but I am very keen to look at all hifi options.
 

Helicopter

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#18
Ety ER20 seems like an obvious choice for testing. 3m has some concert foam plugs that look interesting. 3m tri flange also look good. Hearos also has a bunch of hifi stuff.

@amirm if you are interested in any or all of these, I can drop ship them. They are all pretty cheap, so no pressure on testing... plus there are no concerts here anyway.

Howard Leight put specs on the box for some foam plugs and it looks like attenuation there is basically correlated with frequency. Some lower NRR foam would probably be pretty good, but 33NRR is too much attenuation for a concert IME.
 

dougi

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#19
Ety ER20 seems like an obvious choice for testing. 3m has some concert foam plugs that look interesting. 3m tri flange also look good. Hearos also has a bunch of hifi stuff.

@amirm if you are interested in any or all of these, I can drop ship them. They are all pretty cheap, so no pressure on testing... plus there are no concerts here anyway.

Howard Leight put specs on the box for some foam plugs and it looks like attenuation there is basically correlated with frequency. Some lower NRR foam would probably be pretty good, but 33NRR is too much attenuation for a concert IME.
With the situation in Australia I've been lucky enough to go to two sit down concerts in the last month. Largely solo acoustic or blues guitar so no hearing protection really needed. Props for volunteering the drop ship @Helicopter
 
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Jdunk54nl

Jdunk54nl

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Thread Starter #20
Well it definitely seems to be some interest in this.

I was going to drop ship him some of the more expensive ones I listed originally:

The Earasers:
https://smile.amazon.com/Earasers-HEM001-Musicians-Plugs-Medium/dp/B00E2D9HAA?ref_=ast_sto_dp

The Eargasm:
https://smile.amazon.com/Eargasm-Mu...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Hearos (not expensive)
https://smile.amazon.com/Comfortabl...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==


@amirm What size is the ear on your measurement device?

1620140322845.png
 
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