[jaddie]

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Again, you're confusing audibility and perceived loudness with other reasons for measuring sound.  Recall that phons are based on perceived loudness.  A-weighting is an effort produce a single-number representation of sound that roughly corresponds to human perception in that area.  C-weighting for higher (100?).  Again, this is human perception.

No, I'm not confusing anything, I do understand the difference between audibility, perceived loudness and measurement for safety.  We've sort of been talking around the issue, and I think we actually both do understand and are in agreement on much of this. 
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The OSHA/NIOSH/every-other-organization-concerned-with-hearing-conservation measurements that started this conversation are not concerned with human perception of a sound, but with its ability to cause damage to hair cells.  This is independent of and only somewhat related to human perception.  It is a physical phenomenon, not psycho-acoustical.  It just so happens that A-weighting also works pretty well for predicting damage to our hearing.  It's a different application for the concept, apart from perception.  Whether or not the C-weighting scheme works better for perception at higher levels is irrelevant.
 
There are a handful of papers showing that A-weighting isn't ideal for hearing conservation, including the one you linked to, and I am certainly in the camp that says reducing noise exposure to a single number gives an incomplete picture.  But there are also multiple handfuls of papers showing that A-weighting works reasonably well as a predictor for hearing loss, as long as we choose the correct criterion and exchange rate.

Agreed with all.  
 
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The reason you "MUST" use A-weighting to measure levels that individuals in your venue are exposed to is the vast majority of literature and understanding in hearing conservation is based on A-weighted, broadband levels.  For better or for worse.  It is what we have, even if it's not ideal.
 
It's not possible to reject the use of A-weighting for this task because it leaves you with no point of reference.  You can't just decide to use C-weighting or Z-weighting in place of A, because you can never compare measurements from different weighting schemes.  If your criteria are based in dBA, you must measure dBA or your measurements are meaningless.

I believe I've already said pretty much that in another post.  We use it because its the standard, right or wrong, its the standard.
 
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What does using C-weighting tell you about the sound you're measuring?  It gives you a better understanding of the perceived loudness of the program material, sure, but what do you do with that information?  Serious question.

No, not so much perceived loudness as SPL. It may in some sense be better than the A curve at 100dB SPL, but still not quite right.  
 
 
So, perhaps we might agree on these:
 
A Weighting was designed for low (speech level and below) noise measurements, based on old equal loudness curves that have since been updated.
 
A-weighting is the standard for measurement of high level noise exposure related to safety issues and hearing damage.
 
A-weighting may not be appropriate for use when perceived loudness above 40 phons is required, but again, is a standard and used all the time.  So it must also be used that way.
 
A-weighting would be inappropriate for use during system setup and EQ.
 
A-weighting would be inappropriate for use before an RTA used as a spectral-balance judgement tool at concert levels.
 
How's that? 

 

[RevMen]

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No, not so much perceived loudness as SPL. It may in some sense be better than the A curve at 100dB SPL, but still not quite right.  
 

I'm really not following you here.  Of course you're measuring SPL, that's what the doohickey does.  I'm asking what you do with that information and why A is "invalid" for that purpose.  I'm not trying to get you in a gotcha here, I truly want to understand.
 
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A Weighting was designed for low (speech level and below) noise measurements, based on old equal loudness curves that have since been updated.  

 
I don't think I would say it that way.  I would say A-weighting is modeled after an older version of the 40-phon equal loudness curve, and that it's "designed for" enabling the measurement of a whole sound in a way that (roughly) correlates to human hearing sensitivity.
 
It was a very useful invention at the time because all SLMs were analog (hence the simplified shape of the curve) and frequency bands had to be measured individually, using an expensive filter, which was very inconvenient.  I had to use such a meter in graduate school, it was a real pain in the ass.
 
The A curve isn't married to the 40-phon curve.  It's inspired by it but isn't meant to reproduce it.  That was impossible at the time it was invented (or at least very expensive).  Remember that the equal loudness curves are developed with puretones, while the A and C curves are intended to be applied to whole frequency spans (although filtering puretones with them is still valid).  They're not quite as connected as it seems like you're saying.
 
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A-weighting is the standard for measurement of high level noise exposure related to safety issues and hearing damage.
 

 
Yes.
 
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A-weighting may not be appropriate for use when perceived loudness above 40 phons is required, but again, is a standard and used all the time.  So it must also be used that way.
 

I'm not with you on this.  It completely depends on the application.  For many types of noise sources, the A-weighting curve works very well for predicting perception and annoyance.  See the WHO's "Guidelines for Community Noise" for a review of literally more than a hundred papers and a discussion on whether A-weighting by itself is enough.  They determined that it is.
 
A-weighting is the de facto standard for noise ordinances and other criteria for perceptibility and annoyance, and in most cases it's just fine.  For music noise it's a different story.  Low frequency is more important, because music has strong low frequency content, of course, but also because the low frequency contains rhythmic, repeating patterns, which significantly increase perceptibility.  The usefulness of A-weighting for most sounds and its lack of performance for music are both true at any loudness, not just those around speech or less.
 
When I do an analysis to determine perception or potential annoyance, I never rely on A-weighting alone.  I don't imagine any acoustical engineer that's worth hiring would.  Comparison of 1/3 or 1/1-octave bands to ambient, and sideband comparison is more useful.  At the end of a calculation I can spit out an A-weighted value for comparison to an ordinance or standard, if necessary.
 
So, in short, I agree that it's used frequently, but I disagree with the spirit of saying it "may not be appropriate."  It's appropriate much of the time.
 
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A-weighting would be inappropriate for use during system setup and EQ.
 

 
I would agree that it's not useful in this scenario except for assessing hearing damage potential.
 
 
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A-weighting would be inappropriate for use before an RTA used as a spectral-balance judgement tool at concert levels.
 

 
I wouldn't say "inappropriate," but I would say "not very useful."  It'd be inconvenient, but if you were pretty familiar with the A curve you could still get along.  Sort of like horn players who transpose on the fly.  This is actually the way I usually operate at my current job, which involves assessing industrial noise sources.  I use A-weighting on my 1/3-octave screen to make it easier to pick out frequencies that'll have greater impact on the broadband level, but I have a good enough sense of the weighting curve to be able to "transpose" when I want to know absolute levels in a band.
 
But, yes, we agree in principle here.

 

[Green Golden Retriver]

What are the long term impact of listening to music too loud ?

 

[baskingshark]

What are the long term impact of listening to music too loud ?

Hearing loss, and this is irreversible. Usually higher frequencies are affected first.

My country recommends not to exceed 85 dB for an 8 hour period to protect hearing health.

 

[playmusic]

Hearing loss

First a reduction, then a total loss at some frequencies or in a large frequency range.
Or the reverse: tinitus.
If you are unlucky: hearing loss and tinitus.

Your preferred internet search engine might provide further information ...

 

[Green Golden Retriver]

First a reduction, then a total loss at some frequencies or in a large frequency range.
Or the reverse: tinitus.
If you are unlucky: hearing loss and tinitus.

Your preferred internet search engine might provide further information ...

Ok I’m lowering the volume on my right now on the a90 lol