Brain injuries from loud bass?

#44
863127 said:
Repeated low-intensity impacts, like pulled sparring punches, can cause brain injury, but that's because of the brain hitting against the skull.

Explosions can also cause brain injury:

(Effects of Low-Level Blast Exposure on the Nervous System: Is There Really a Controversy?)
"...Questions have also emerged as to whether pathophysiologically blast-related TBI is different from the type of non-blast TBI (nbTBI) typical of civilian trauma where injury is caused by inertial and rotational forces along with the effects of blunt impact (37, 38). The most direct physical effects of these forces are bleeding, direct tissue damage, and mechanical shear stress along white matter tracts, which in turn leads to activation of a variety of pathophysiological cascades that are associated with further tissue damage (37, 39). Blast injuries by contrast result from a pressure wave generated at a distance and transmitted though air, which may induce stresses in the brain without significant global motions being imparted. Damage to the nervous system is thought to occur through biophysical mechanisms related to the traveling shock wave’s interaction with the brain (40–42), although it has also been suggested that a blast wave striking the body can induce oscillating pressure waves, which can be transmitted through the systemic circulation to the brain (12, 43)..."

Loud bass frequencies can vibrate things visibly. If I'm listening to music in the car with loud bass, the rearview mirrors vibrate enough to be blurry, without a subwoofer, just on little factory economy car speakers. It's small impacts compared to boxing or explosives, but what about the cumulative effect with enough time? And with a louder bass amp?

Is it not commonly known that bassists are getting brain injuries just because of how weird the bassists already were? Is the SVT making me r-worded or is it not the SVT's fault?
Click to expand...

Interesting thought. I don’t know what the science says, but I’ve had the misfortune of being a little too close to a few very loud bangs in my time (in conflicts far away and a long time ago), and I’d be surprised if standing in front of a 8x10 night after night for years on end got anywhere close to the effect on the brain of a single instance of superheated air expanding in your general direction at 10,000 feet a second! The effect on hearing may be comparable... (around 180dB close up to the big stuff... but then you’re dead anyway... and easily >130dB on the margins) but that incredible compression wave is something else. Like the feeling you get when you drop into the deep end of a swimming pool from the highest diving platform, but multiplied many times over. Trouser-leg flapping PA subwoofers are a light breeze by comparison.
 
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#47
knumbskull said:
That would explain a lot round here.
Click to expand...
Screenshot_20201124-165301_Chrome.jpg
 
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#50
way back when I was young and had roadies, I had a rig with 4- 15's. 2 - 10 cubic ft boxes for 2 speakers which was a little larger than the Sunn 2000 cabinets and precision tuned ports. I was pushing it with a 2400 watt solid state and and a Yamaha PB1 pre. And when I cranked it, if you were within range it would shake your eyeballs, kind of like driving over a washboard. Certain notes would hit you in the chest so hard it made it harder to breathe, too. So if it was shaking my chest and rattling my eyeballs no wonder I have a hard time remembering stuff now..
 
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#52
863127 said:
Attenuation of Sound Waves

"...Absorption is the conversion of the sound energy to other forms of energy. The combined effect of scattering and absorption is called attenuation... The amplitude change of a decaying plane wave can be expressed as:

A = Ao*(e^-az)

In this expression Ao is the unattenuated amplitude of the propagating wave at some location. The amplitude A is the reduced amplitude after the wave has traveled a distance z from that initial location. The quantity is the attenuation coefficient of the wave traveling in the z-direction. The dimensions of are nepers/length, where a neper is a dimensionless quantity. The term e is the exponential (or Napier's constant) which is equal to approximately 2.71828.

The units of the attenuation value in Nepers per meter (Np/m) can be converted to decibels/length by dividing by 0.1151. Decibels is a more common unit when relating the amplitudes of two signals."

___

Attenuation Constant » IT'IS Foundation

I entered "Frequency: 100 Hz"

Attenuation constant of
Skull cortical: 0.00545529
Cerebrospinal fluid: 0.00000999
Brain: 0.000042925

Divide those by 0.1151 to use db...
Skull cortical: 0.047396
CSF: 0.00008679
Brain: 0.00037293

___

Back to the equation

A = Ao*(e^-αz)

through 1/4" of skull
A = 120db * (2.71828 ^ -(0.047396 * .25 inches))
A = 118.586 db

then through ~5 mm of CSF
A = 118.5 db * (2.71828 ^ -(0.00008679 x .2"))
A = 118.497 db

then through 3" of brain
A = 118.4 db * (2.71828 ^ -(0.00037293 x 3"))
A = 118.268 db


At 130 db

through 1/4" of skull
A = 130db * (2.71828 ^ -(0.047396 * .25 inches))
A = 128.469 db

then through ~5 mm of CSF
A = 128.5 db * (2.71828 ^ -(0.00008679 x .2"))
A = 128.498 db

then through 3" of brain
A = 128.4 db * (2.71828 ^ -(0.00037293 x 3"))
A = 128.25 db

___


My calculations confirm, as I suspected, that when a bass amp vibrates the walls throughout a house, it does the same to my brains. Our hypothesis that this is making me r-worded will require further research.
Click to expand...

Let's do a reality check on how loud an SVT plays:

Ampeg SVT is rated for 300W, but typically makes about 270W reasonably clean. I believe they make about 350W at about 10% THD

Sensitivity rating for the 810E is 100dB 1w/1m The decibel change from 1W to 300W is about 25dB. So if you feed an 810E 300W, the SPL will be about 125dB. To get 130dB out of an 810E you need 1,000W, which is 200W above the cab's RMS power rating. Another options would be to split ~500W into a pair of 810Es....but an SVT does not make 500W. You need two SVTs and two 810e to produce 130dB.

I don't think most people even run one SVT and 810 into output drive.

One time I performed on one of those small portable stages that folds out from a trailer. We had four Apogee AE12s tight packed in front of the stage, so essentially I was standing a few inches above, and few feet behind they subwoofer array. Each AE12 is rated for 132dB continuous, 138dB peak, and 145dB mechanical limit. I don't know if I experienced any brain damage, but I definitely experienced vertigo and nausea. I asked the audio tech to turn the system down a bit :vomit:. That's the loudest bass I have ever experienced.

I think the one aspect of your premise that way be flawed is the rate of acceleration and deceleration is probably not sufficient. Also the brain and skull will tend to vibrate together to some degree. In contrast, injury occurs when the skull experiences a rapid acceleration or deceleration that results in a collision between the brain and skull. No collision will occur if the brain and skull are vibrating as a single mass. Now if they vibrate out of phase, due to different resonances, you may have a point.


Here is an article that supports your general premise...but an SVT would not be be capable of producing sufficient sound pressure in the frequency range that does damage. Read the part related to 7hz.
COLUMN: Low-frequency sound is silent, but it can kill you
 
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#53
Bruiser Stone said:
I can only attest to my personal experience. Granted the guitarist was dealing a full Marshall stack, everything was downtuned, and it was a small-medium indoor venue. But it felt like the loudest show I’ve ever attended. And I’ve seen Sleep twice.

It was “what did I just do” stupid loud.
Click to expand...

I had a vocal PA decades ago that got booked for a "heavy band" in a tiny little pub about the size of a3 car garage/shed. 2 guitarists with Marshall stacks & think the bass was a bigger Peavey. My PA couldn't come close and the singer was pretty cranky and even the bass struggled. The drummer probably made his living as a removalist or a rigger - he was loud when he was quiet. Anway, about 4 or 5 songs in the owner came down, paid them and told them to leave. Stupid loud indeed. (Had ear plugs under a pair of Muff painted black with Sony stickers. You could get away with that in big dark venues but I got caught out - and wore them anyway.)

Have to say, I spent years driving with my window open and a lot of time on motorbikes under the helmet, and if I do a long highway drive with the windows down now my ears get fatigued which quickly turns to pain. So I do believe pressure has an impact.
 
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#54
863127 said:
Repeated low-intensity impacts, like pulled sparring punches, can cause brain injury, but that's because of the brain hitting against the skull.

Explosions can also cause brain injury:

(Effects of Low-Level Blast Exposure on the Nervous System: Is There Really a Controversy?)
"...Questions have also emerged as to whether pathophysiologically blast-related TBI is different from the type of non-blast TBI (nbTBI) typical of civilian trauma where injury is caused by inertial and rotational forces along with the effects of blunt impact (37, 38). The most direct physical effects of these forces are bleeding, direct tissue damage, and mechanical shear stress along white matter tracts, which in turn leads to activation of a variety of pathophysiological cascades that are associated with further tissue damage (37, 39). Blast injuries by contrast result from a pressure wave generated at a distance and transmitted though air, which may induce stresses in the brain without significant global motions being imparted. Damage to the nervous system is thought to occur through biophysical mechanisms related to the traveling shock wave’s interaction with the brain (40–42), although it has also been suggested that a blast wave striking the body can induce oscillating pressure waves, which can be transmitted through the systemic circulation to the brain (12, 43)..."

Loud bass frequencies can vibrate things visibly. If I'm listening to music in the car with loud bass, the rearview mirrors vibrate enough to be blurry, without a subwoofer, just on little factory economy car speakers. It's small impacts compared to boxing or explosives, but what about the cumulative effect with enough time? And with a louder bass amp?

Is it not commonly known that bassists are getting brain injuries just because of how weird the bassists already were? Is the SVT making me r-worded or is it not the SVT's fault?
Click to expand...
That explains a few things
 
#55
I have never experienced any issues with this over the years - but we don't really play that loud.

I experienced a pretty big concussion earlier this year (metal handle on a press hit my head after it broke under tension - left a dent that is still there many months later). Thankfully the MRI showed that there was no bleeding or anything - but now I am in that system and due for another MRI next year... lol

It was honestly the worst experience of my life - and I am still dealing with some issues from it (migraine headaches if I over stress myself, lose sleep or eat sugar). When it happened - I can't even describe how weird everything felt and looked.

I was unable to play music for the first 3 months - and when I did start rehearsing again, I was unable to put up with cacophony in between songs anymore (not as bad now as it was a few months ago - it would completely disable my thought process when I first started, and our jams were initially no longer than 15minutes to a 1/2 hour).

The funny thing is - ever since it happened, I have become more optimistic (and apparently funnier to those I know) and more socially outgoing... which is pretty cool, I guess :p
 
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#56
MuttThud said:
Interesting thought. I don’t know what the science says, but I’ve had the misfortune of being a little too close to a few very loud bangs in my time (in conflicts far away and a long time ago), and I’d be surprised if standing in front of a 8x10 night after night for years on end got anywhere close to the effect on the brain of a single instance of superheated air expanding in your general direction at 10,000 feet a second! The effect on hearing may be comparable... (around 180dB close up to the big stuff... but then you’re dead anyway... and easily >130dB on the margins) but that incredible compression wave is something else. Like the feeling you get when you drop into the deep end of a swimming pool from the highest diving platform, but multiplied many times over. Trouser-leg flapping PA subwoofers are a light breeze by comparison.
Click to expand...

Happy Thanksgiving to you and yours sir.
 
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#59
Wasnex said:
Let's do a reality check on how loud an SVT plays:

Ampeg SVT is rated for 300W, but typically makes about 270W reasonably clean. I believe they make about 350W at about 10% THD

Sensitivity rating for the 810E is 100dB 1w/1m The decibel change from 1W to 300W is about 25dB. So if you feed an 810E 300W, the SPL will be about 125dB. To get 130dB out of an 810E you need 1,000W, which is 200W above the cab's RMS power rating. Another options would be to split ~500W into a pair of 810Es....but an SVT does not make 500W. You need two SVTs and two 810e to produce 130dB.

I don't think most people even run one SVT and 810 into output drive.

One time I performed on one of those small portable stages that folds out from a trailer. We had four Apogee AE12s tight packed in front of the stage, so essentially I was standing a few inches above, and few feet behind they subwoofer array. Each AE12 is rated for 132dB continuous, 138dB peak, and 145dB mechanical limit. I don't know if I experienced any brain damage, but I definitely experienced vertigo and nausea. I asked the audio tech to turn the system down a bit :vomit:. That's the loudest bass I have ever experienced.

I think the one aspect of your premise that way be flawed is the rate of acceleration and deceleration is probably not sufficient. Also the brain and skull will tend to vibrate together to some degree. In contrast, injury occurs when the skull experiences a rapid acceleration or deceleration that results in a collision between the brain and skull. No collision will occur if the brain and skull are vibrating as a single mass. Now if they vibrate out of phase, due to different resonances, you may have a point.


Here is an article that supports your general premise...but an SVT would not be be capable of producing sufficient sound pressure in the frequency range that does damage. Read the part related to 7hz.
COLUMN: Low-frequency sound is silent, but it can kill you
Click to expand...

From the article:
"...the low frequency of a tuba is 29 hz and of a bass 27 hz. Below 20 hz, it’s called “infrasound.” Those sounds are imperceptible to the human ear, but the body hears it, although one may not be aware of the bombardment.

These sounds might occur from the whir of motors, water pumps, construction-site noise, an equipment room near your residence, or close-by traffic.

Daria Vaisman, a research editor at the New York Press, told of an incident with Walt Disney and his team of cartoonists. After they slowed down a 60-cycle tone in a short cartoon to 12 hz, they became sick for days afterward...

The most dangerous frequency is at the median alpha-rhythm frequencies of the brain: 7 hz. This is also the resonant frequency of the body’s organs. At high volumes, infrasound can directly affect the human central nervous system, causing disorientation, anxiety, panic, bowel spasms, nausea, vomiting and eventually organ rupture or even death from prolonged exposure.

The first documented attempt to reproduce the infrasound effects was by Vladimir Gavreau in 1957. He became interested in infrasound when asked to cure a case of “sick building syndrome.”

The staff at a research plant in Marseilles, France, were mysteriously falling ill. Chemical or pathogen poisoning was suspected, but Gavreau eventually traced the origin of the illnesses to air conditioning units’ rotating fans that were generating low-frequency sound waves.

Gavreau began to experiment with low-frequency acoustics with the intention of creating a viable audio weapon for the French military. Several prototype designs were produced, christened “canon sonique,” consisting of piston-driven tubes and smaller compressed air horns and whistles.

Gavreau and his team tested the instruments on themselves at the Marseilles plant, with unexpected results. One of the team members died instantly, 'his internal organs mashed into an amorphous jelly by the vibrations.'

Fortunately, they could turn it off quickly. Even so, others in nearby laboratories were sick for hours. Everything was vibrating: stomach, heart, lungs..."​

"We should have known not to let him work on the canon; we should have known this would happen to him. When Pierre became dangerously willing to sacrifice himself for the experiments, we would try to tell him, try to remind him to be careful; we would tease him like a boy -- 'Pierre le petit creampuff!', we would say. But he had always sternly insisted, 'No. I am a jelly donut.' He was our jelly donut."

azureblue said:
way back when I was young and had roadies, I had a rig with 4- 15's. 2 - 10 cubic ft boxes for 2 speakers which was a little larger than the Sunn 2000 cabinets and precision tuned ports. I was pushing it with a 2400 watt solid state and and a Yamaha PB1 pre. And when I cranked it, if you were within range it would shake your eyeballs, kind of like driving over a washboard. Certain notes would hit you in the chest so hard it made it harder to breathe, too. So if it was shaking my chest and rattling my eyeballs no wonder I have a hard time remembering stuff now..
Click to expand...

:laugh: :thumbsup:
From that same article:
"Sounds around 19 hz match the resonant frequency of the human eyeball, with reports of apparitions as detailed by the Coventry Telegraph newspaper."
 
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