NEW DISCOVERIES ABOUT HEARING LOSS ?

[haraldo]

Here is a report from a guy called Larry Robinson that discusses the different guidelines for what is safe SPL levels as guided by some standardization organizations.

It is claimed in this report that there is no such things as age related hearing loss, there are no references so I wonder if this can be true or not?

Here's what's stated:

NEW DISCOVERIES ABOUT HEARING LOSS
Recent research has indicated two new facts about hearing loss:

1. NO SUCH THING AS AGE-RELATED HEARING LOSS
   Age related hearing loss is now thought to not exist. Instead, what was thought to be age-related hearing loss has now been found to be acquired hearing loss from cumulative exposures to the loud sounds of steam trains, firearms, and factories.
   
   
2. HEARING DAMAGE FROM LOW FREQUENCY AND INFRASONIC SOUND
   Extremely low frequency sounds do not follow the tables above, because the weighting curves used for the sound measurements above are based on audibility. But it is now thought that frequencies under 60 Hz, and especially those approaching DC impulse transients, cause hearing damage, even though they are not very audible. This damage begins in the "rock range", starting between 2 KHz and 6 KHz, and expanding in frequency range as exposure continues. So the following precautions should be taken:
   
   • Infrasonic filters rolling off at 30 Hz should be inserted in all subwoofer, house, and monitor feeds.
   • Subharmonic generators (bass enhancers) must not be used.
   • If the sound is felt in a person's chest, it is too loud in the infrasonic region. It is causing hearing damage even though it is not heard to be that loud.
   • Infrasonic filters should be inserted in the instrument outputs of certain instruments. For example, some Yamaha instruments are known to output DC transients.
   • A new weighting curve, Z weighting (dBZ), has been created for SPL meters so this hazard may be measured.
   • Often the damage is done to people farther from the speakers. A 20 Hz wave does not fully form until the sound is 28 feet from the speaker.

 

[TheWarrior]

Glad to know I listen within safe ranges!

I too have heard this before. It makes a lot sense, we subject ourselves to incredible SPL's in every day life.

My nerve is damaged from landing on my head, causing an obstruction in the flow of fluid with in the vestibular canal, presenting frequent vertigo. This can also be caused by a developmental disorder in which a 'therapy' is available to teach you to bend your head in specific ways to alleviate the symptoms. I'll be trying that out soon just to see if any improvement is to be found, but the surgeon who operated on me made it pretty clear that I was going to need to learn to live with it, even at the expense of my hearing.

So I am trying desperately to use my hearing as best as I can to enjoy sweet sounds from quality speakers, and wear heavy ear protection for everything else including vacuuming!

 

[haraldo]

Glad to know I listen within safe ranges!

I too have heard this before. It makes a lot sense, we subject ourselves to incredible SPL's in every day life.

My nerve is damaged from landing on my head, causing an obstruction in the flow of fluid with in the vestibular canal, presenting frequent vertigo. This can also be caused by a developmental disorder in which a 'therapy' is available to teach you to bend your head in specific ways to alleviate the symptoms. I'll be trying that out soon just to see if any improvement is to be found, but the surgeon who operated on me made it pretty clear that I was going to need to learn to live with it, even at the expense of my hearing.

So I am trying desperately to use my hearing as best as I can to enjoy sweet sounds from quality speakers, and wear heavy ear protection for everything else including vacuuming!

Sorry to hear about the nerve damage !!

What suprised me the most about this report is how it's claimed that even not very loud infrasonic soundwaves can give you a hearing loss, or at least it's what's claimed...

 

[Cosmic Char]

Glad to know I listen within safe ranges!

I too have heard this before. It makes a lot sense, we subject ourselves to incredible SPL's in every day life.

My nerve is damaged from landing on my head, causing an obstruction in the flow of fluid with in the vestibular canal, presenting frequent vertigo. This can also be caused by a developmental disorder in which a 'therapy' is available to teach you to bend your head in specific ways to alleviate the symptoms. I'll be trying that out soon just to see if any improvement is to be found, but the surgeon who operated on me made it pretty clear that I was going to need to learn to live with it, even at the expense of my hearing.

So I am trying desperately to use my hearing as best as I can to enjoy sweet sounds from quality speakers, and wear heavy ear protection for everything else including vacuuming!

I agree environmental factors contribute vastly to hearing loss, but there is a metabolic factor as well. Here is a great article discussions the differences in the two disorders. Interesting discussion regarding low frequency damage, as I am sure traditional prophylactics are ineffective, exposing millions of workers to potential damage. I myself, have noticed damage coming from my motorcycle. Damned EPA was right!

 

[TheWarrior]

Sorry to hear about the nerve damage !!

What suprised me the most about this report is how it's claimed that even not very loud infrasonic soundwaves can give you a hearing loss, or at least it's what's claimed...

I guess it is similar to high SPL's, where as low frequencies that are heavily amplified effectively 'wear' on the ear over time. So whether you measure that hearing loss with a persons age, or time spent as a roadie working on concert set up, for example, ultimately reduces a person hearing sensitivity leading to hearing loss.

 

[TheWarrior]

I agree environmental factors contribute vastly to hearing loss, but there is a metabolic factor as well. Here is a great article discussions the differences in the two disorders. Interesting discussion regarding low frequency damage, as I am sure traditional prophylactics are ineffective, exposing millions of workers to potential damage. I myself, have noticed damage coming from my motorcycle. Damned EPA was right!

That is a fascinating article, and I only went to page 5! Thank you for sharing!

However I do, now, believe in the adage 'loud pipes save lives' and wonder had I been riding my buddies old ST4S (the original with the 996 motor) and an open air box, I might have not wrecked. As apparently, a giant motorcycle with 3 head lights is still invisible if no one looks for it! RIP mein Gelände Strasse!

Keep the rubber side down!

 

[AcuDefTechGuy]

Moderation in volume level @ all frequencies is good.

THX Reference level @ 105dB for each speaker & 115dB for each Subwoofer is bad.

 

[Speedskater]

When someone goes to that much reference work on a web page, the should include links to a ton of science and medical reference papers.

 

[haraldo]

Came across this:
http://www.baudline.com/erik/bass/facts_about_bass.html

In the early seventies the French military built a prototype sonic deathray called "Le Monstre." It was a phased array (row) of resonant tubes powered by a jet engine. Just like radio and medical sonograms, the phased array could be steered. The resonant tubes were 78 feet in length for an extremely directional 7Hz output. This horrific device could kill a man more than a mile away!

A 7Hz tone of sufficient amplitude can crack the walls of a masonry building and can affect a phenomenon known as brain entertainment whereby normal brainwave frequencies are reclocked and vital processes are catastrophically disrupted. Individuals, thus 'down converted,' usually die within seconds, though not before experiencing excruciating pain as internal organs are literally churned by tsunamis of air. Terrifying indeed."
- Dan Sweeny, WSR v6 n1 issue 32

Not stated anywhere what this 7Hz SPL level should be though... but there are even references to scientists being killed in experiments of investigating the Ionospheric 7Hz Schumann resonance...

It's stated here: The atmospheric cavity Schumann Resonance spectrum has been measured via electronic detection instruments. This Schumann Resonance, which occurs within the Earth and its surrounding energy field, has immediate impact upon planetary life-forms.

It's claimed that in some lab was experimenting with ultra-low frequency electromagnetic transmissions and the Schumann resonance of the Earth's ionosphere (about 7Hz), when
some vibrations in the machine produced the corresponding 7Hz sound waves
which set up a resonance in his diaphragm muscle and he died of internal
damage accordingly.

I could not find any good references to this though... I don't find it so strange that there could be some specific resonance frequencies in our bodies that we should not play around with. And think about it, our bodies are designed to cope with the environment as it was before we had subwoofers, and in these environments there were no strong 7Hz soundwaves ever, at least it's what I think... IMHO

Other than this last statement, none of these are my opinions, just some more or less well founded things I easily found on this...

 

[shadyJ]

You should try to be more skeptical of all of this stuff. First of all, that 'new discoveries' page does not cite anything. The latest science of the kind of damage that bass can do to your ears that I know about is from this study, which does not say the same thing as your link. High levels of Low frequencies can cause temporary threshold shifts which leave the ear vulnerable to higher frequencies which can turn those temporary threshold shifts into permanent threshold shifts (hearing damage). It hasn't been demonstrated, as far as I know, that low frequencies or especially infrasonic frequencies can cause permanent threshold shifts. The subject needs more research, but the existing body of research does not reflect what your link is saying, as far as I know (I am not an audiologist). It looks to me like the pet theories of someone who is a bit on the outside.

As far as your "Le Monstre" story goes, that has been debunked. If you want to know about what has been done to weaponize sound, here is a short article, and here is a more comprehensive longer article which summerizes the efforts in this area. There is no Le Monstre, sorry to say, that is debunked in the first article.

Don't trust articles that do not cite actual science.

 

[TheWarrior]

You should try to be more skeptical of all of this stuff. First of all, that 'new discoveries' page does not cite anything. The latest science of the kind of damage that bass can do to your ears that I know about is from this study, which does not say the same thing as your link. High levels of Low frequencies can cause temporary threshold shifts which leave the ear vulnerable to higher frequencies which can turn those temporary threshold shifts into permanent threshold shifts (hearing damage). It hasn't been demonstrated, as far as I know, that low frequencies or especially infrasonic frequencies can cause permanent threshold shifts. The subject needs more research, but the existing body of research does not reflect what your link is saying, as far as I know (I am not an audiologist). It looks to me like the pet theories of someone who is a bit on the outside.

As far as your "Le Monstre" story goes, that has been debunked. If you want to know about what has been done to weaponize sound, here is a short article, and here is a more comprehensive longer article which summerizes the efforts in this area. There is no Le Monstre, sorry to say, that is debunked in the first article.

Don't trust articles that do not cite actual science.

But they do cite actual tables from their respective agencies, on recommended exposures. I totally agree that this is 'not new', as of 2016, but does convey the basic idea that ADTG put so succinctly!

 

[Steve81]

And think about it, our bodies are designed to cope with the environment as it was before we had subwoofers, and in these environments there were no strong 7Hz soundwaves ever, at least it's what I think... IMHO

FWIW, there are several natural and manmade sources of infrasound beyond loudspeakers that can achieve high levels:
https://en.wikipedia.org/wiki/Infrasound#Sources
After all, plenty of the infrasound on our discs got there by being recorded, ala the cannon-fire from Telarc's 1812 Overture, which extends into the single digits.

 

[haraldo]

FWIW, there are several natural and manmade sources of infrasound beyond loudspeakers that can achieve high levels:
https://en.wikipedia.org/wiki/Infrasound#Sources
After all, plenty of the infrasound on our discs got there by being recorded, ala the cannon-fire from Telarc's 1812 Overture, which extends into the single digits.

Man made sources are of recent origin, it has really no relevance I believe... Our organisms have evolved over billions of years according to conditions that were, providing us the best chances to survive; When there were no guns... or devices of any kind, only the sun and mother earth.

Maybe this 7hz thing is rubbish, but what is bugging me is that there seem to be quite a few independent sources stating the same

You should try to be more skeptical of all of this stuff. First of all, that 'new discoveries' page does not cite anything. The latest science of the kind of damage that bass can do to your ears that I know about is from this study, which does not say the same thing as your link. High levels of Low frequencies can cause temporary threshold shifts which leave the ear vulnerable to higher frequencies which can turn those temporary threshold shifts into permanent threshold shifts (hearing damage). It hasn't been demonstrated, as far as I know, that low frequencies or especially infrasonic frequencies can cause permanent threshold shifts. The subject needs more research, but the existing body of research does not reflect what your link is saying, as far as I know (I am not an audiologist). It looks to me like the pet theories of someone who is a bit on the outside.

As far as your "Le Monstre" story goes, that has been debunked. If you want to know about what has been done to weaponize sound, here is a short article, and here is a more comprehensive longer article which summerizes the efforts in this area. There is no Le Monstre, sorry to say, that is debunked in the first article.

Don't trust articles that do not cite actual science.

From another point of view

You should try to be more skeptical of all of this stuff. First of all, that 'new discoveries' page does not cite anything. The latest science of the kind of damage that bass can do to your ears that I know about is from this study, which does not say the same thing as your link. High levels of Low frequencies can cause temporary threshold shifts which leave the ear vulnerable to higher frequencies which can turn those temporary threshold shifts into permanent threshold shifts (hearing damage). It hasn't been demonstrated, as far as I know, that low frequencies or especially infrasonic frequencies can cause permanent threshold shifts. The subject needs more research, but the existing body of research does not reflect what your link is saying, as far as I know (I am not an audiologist). It looks to me like the pet theories of someone who is a bit on the outside.

As far as your "Le Monstre" story goes, that has been debunked. If you want to know about what has been done to weaponize sound, here is a short article, and here is a more comprehensive longer article which summerizes the efforts in this area. There is no Le Monstre, sorry to say, that is debunked in the first article.

Don't trust articles that do not cite actual science.

I am not taking any side, one way or another...

You don't need to be a scientist to realize that we ALL suffer from hearing loss, believed to be age related... and I believe we don't even properly know the reason for this, or am I wrong on that one...

 

[Cosmic Char]

I am studied in this area. I agree there is no "normal" age related hearing loss. I find the low frequency question interesting, and there does need to be more research on the topic. As with most areas of medicine and science. If we continue to expand our lifespans, this will be a more pressing problem, as most of our lives have increasing sound exposure, especially in urban settings. I see a ton of veterans who have significant trouble hearing, especially combat vets.
There has been some linkage of repeated shock wave events from IEDs that cause neural disruption/nodule development in the brain. I do not know if this is due to low frequency, shearing stress, or acceleration/deceleration injury. It is quite fascinating, however.

 

[Steve81]

Man made sources are of recent origin, it has really no relevance I believe...

Man-made sources of infrasound are not necessarily relevant to our current state of evolution, but humanity's regular exposure to it for generations would tend to indicate that the levels we experience in a home theater aren't liable to kill us either.

Of course if you're interested in a more natural example, look no further than a large waterfall like Niagara Falls, which produces truly immense amounts of sound all the way down to 1Hz and below. Interestingly enough, there's also an attraction there at the Table Rock Welcome Center called Niagara's Fury. To recreate the power of the falls, they utilize no less than 6 rotary woofers.
http://www.rotarywoofer.com/niagara fury index.html

 

[haraldo]

Man-made sources of infrasound are not necessarily relevant to our current state of evolution, but humanity's regular exposure to it for generations would tend to indicate that the levels we experience in a home theater aren't liable to kill us either.

Of course if you're interested in a more natural example, look no further than a large waterfall like Niagara Falls, which produces truly immense amounts of sound all the way down to 1Hz and below. Interestingly enough, there's also an attraction there at the Table Rock Welcome Center called Niagara's Fury. To recreate the power of the falls, they utilize no less than 6 rotary woofers.
http://www.rotarywoofer.com/niagara fury index.html

Maybe this experiment should have killed a lot of people but it didn't.... there's lots of SPL around 7Hz here!

Well, I never heard of anyone getting into trouble caused by the soundwaves from a waterfall... The thing though is that it's claimed that there is a very precise resonancy frequency that can trigger problems, and although you definitely have strong infrasonic soundwaves coming from a waterfall, it may not be the exact 7.xxx that is required.

Could it be that you actually need a pure sinewave at the exact 7.xxx frequency to really properly trigger such a resonance in qurstion?

I'm just guessing now...

Will look for more references!

 

[Cosmic Char]

I wonder how many workers have hearing damage that work at the falls? With this natural source, it would be very difficult to separate out the audible range of hearing damage from the low frequency damage. That could only be done in a lab, I would imagine.

 

[HDOM]

So the following precautions should be taken:

1. • Infrasonic filters rolling off at 30 Hz should be inserted in all subwoofer, house, and monitor feeds.
   • Subharmonic generators (bass enhancers) must not be used.
   • If the sound is felt in a person's chest, it is too loud in the infrasonic region. It is causing hearing damage even though it is not heard to be that loud.
   • Infrasonic filters should be inserted in the instrument outputs of certain instruments. For example, some Yamaha instruments are known to output DC transients.
   • A new weighting curve, Z weighting (dBZ), has been created for SPL meters so this hazard may be measured.
   • Often the damage is done to people farther from the speakers. A 20 Hz wave does not fully form until the sound is 28 feet from the speaker.

i dont have subwoofer and never will so there i am free, also i dont have bass enhancers, i use 2 ways litle monitors and nver feel any felt any feeeling in my chest also is not a luxury audio so it never gets down to 20 or 30 Hz it gets down to minimum 51 Hz, another reason why i like more these speakers than the new ones made for 24 bit music and my room is maximun 4 meter long so i am never far from the speaker and never listen to much load, and never listen to music like hard rock or that kind of modern stuff that sound to harsh in my ears

 

[Steve81]

I'm just guessing now...

Will look for more references!

This article might be of interest to you:
http://www.audioholics.com/room-acoustics/bass-the-physical-sensation-of-sound

2-10 Hz
An experiment with 25 subjects reported a subjective “feeling of body sway” when exposed to 2-10 Hz tones above 130 dB, with the effect most pronounced at 7 Hz. Vertical Nystagmus (involuntary movement of the eye) was also reported. Another test that exposed subjects to 5-10 Hz tones at 150 dB reported nostril vibration. One tester subjected ten normal hearing and ten deaf participants to a 6 Hz tone at 115 dB for 20 minutes and found changes in EEG patterns (described as ‘diminished wakefulness) in the hearing participants accompanied by changes in pulse and blood pressure. However these effects were not found in the deaf subjects. Other tests in the 5-10 Hz range found decreased respiration, depressed blood flow in the brain, and changes in pulse and blood pressure. Subjective complaints of testing in this frequency band included body vibrations, pressure in the ear, and an inability to concentrate.

 

[Cosmic Char]

Cool article. Too bad the N was so low... No statistical analysis would be worthwhile of the data.