How loud is too loud?

[3db]

Okay today I have been listening to The Dark Knight Rises Ultimate Complete Score (not OST).

And I wanted to see how loud I listen, which I think is pretty loud, but comfortably loud, not painfully loud.

I set for Peak SPL in both dB-A & dB-C.

A-weighting (dBA) filters out the low frequencies and covers ~ 500Hz-10kHz. By comparison, C-weighting (dBC) is almost unweighted so it covers ~ 32Hz-10kHz.

My Peak SPL: 82.5dBA & 97.5dBC.

I deduce that most of the sound level peak is from the BASS (32-500Hz) since the peak dBA is only 82.5dB (500Hz-10kHz).

OSHA Sound Levels are in dBA (Slow Response), not dBC.


Comparison of Duration Per Day in Hours to Allowable Sound Level in dBA (Slow-Response SPL)


Duration per day (hours) vs. Sound level (dBA, slow response):


8 hr 90 dBA
6 hr 92 dBA
4 hr 95 dBA
2 hr 100 dBA
1 hr 105 dBA
1/2 hr 110 dBA
1/4 hr 115 dBA

So does that mean I am way under the 90dBA OSHA Noise standard?

What????

I can't hear you

 

[AcuDefTechGuy]

What????

I can't hear you

OSHA does not recommend > 8 hrs exposure to 90dBA.

My peak SPL is only 82.5dBA (500Hz-10kHz).

But my peak SPL is also 97.5 dBC (mainly from the subwoofers).

I guess OSHA does not care about dBC?

They only care about dBA which covers 500Hz-10kHz?

 

[Gordonj]

If you ride a motorcycle, have a car with loud exhaust (like a Honda mosquito), work in an environment with loud noise, use firearms or anything like these, you should be wearing hearing protection EVERY time.

And least forget about; lawn mowers, weed eaters, chain saws, the car stereo, ear buds, etc..

These can do the same, if not more, damage due to the duration of exposure at volumes....

Gordon

 

[Grador]

Personally I feel that OSHA limits are pretty lenient, I wouldn't go by them for keeping your hearing sharp.

For some further reading on why your A-weight readings may not be all you think they are: A-weighting - Wikipedia, the free encyclopedia

 

[3db]

I've been thinking about these numbers to SPL exposure but the one thing that's missing ( at least I didn't see it ) is at what frequency/frequencies are we more susceptible to hearing damage. I have a hard time believing that being exposed to bass at 90db will offer the same deterioration of hearing compared to frequencies at 1Khz or at 10Kz. Does anyone have any numbers behind the frequency. After all human hearing is most sensitive to midrange and highs than it is to bass.

 

[Steve81]

I have a hard time believing that being exposed to bass at 90db will offer the same deterioration of hearing compared to frequencies at 1Khz or at 10Kz. Does anyone have any numbers behind the frequency. After all human hearing is most sensitive to midrange and highs than it is to bass.

I've seen a lot of conflicting information floating out there regarding this. For example, at the NIH's website on noise induced hearing loss, frequency / weighting isn't mentioned at all.
Noise-Induced Hearing Loss

Here's also one presumably educated opinion on the subject from an ENT over at WebMD:
"How does a subwoofer affect hearing?": Ear, Nose & Throat Community - Support Group

OTOH, this site mentions that lower frequencies are less damaging than higher frequencies, though how much less isn't mentioned:
Noise Induced Hearing Loss | American Hearing Research Foundation
Presumably if you're turning your subs up to night club levels, you're still likely doing significant damage. In either case, I prefer to err to the side of caution as I'd just assume have as good of hearing as is possible in 40 years.

 

[AcuDefTechGuy]

I've been thinking about these numbers to SPL exposure but the one thing that's missing ( at least I didn't see it ) is at what frequency/frequencies are we more susceptible to hearing damage. I have a hard time believing that being exposed to bass at 90db will offer the same deterioration of hearing compared to frequencies at 1Khz or at 10Kz. Does anyone have any numbers behind the frequency. After all human hearing is most sensitive to midrange and highs than it is to bass.

I think that's why OSHA uses the A-weighted scale, which only looks at frequencies from about 500Hz-10kHz and not below 500Hz.

If we use the C-Weighted scale, I think all of us are listening too loudly because it's going to be > 90 dBC w/ the subs.

So basically the A-Weighted scale measures the Speakers only and the C-Weighted scale measures both Speakers + Subs.

Translate this to "THX Reference Levels" and we get a 105 dBA peak & 115 dBC peak.

And I was listening very loudly @ 82.5 dBA peak & 97.5 dBC peak.

 

[Swerd]

I've been thinking about these numbers to SPL exposure but the one thing that's missing (at least I didn't see it ) is at what frequency/frequencies are we more susceptible to hearing damage. I have a hard time believing that being exposed to bass at 90db will offer the same deterioration of hearing compared to frequencies at 1Khz or at 10Kz. Does anyone have any numbers behind the frequency. After all human hearing is most sensitive to midrange and highs than it is to bass.

It may be a mistake to assume that exposure to a particular frequency or range of frequencies results with damage to those hair cells that respond to those frequencies.

I'm not at all familiar with what is known about this, but one thing seems to be clear. Damage to hearing begins with losses in the cells that respond to high frequencies. It seems to be caused by being exposed to loud sounds, but not necessarily loud high frequencies.

Loss of hearing can also be caused by other causes unrelated to loud sounds, such as long exposure to certain drugs.

 

[cpp]

Its too loud if after you completed your listening, your ears ring.. Congratulations you have finally entered into the world of inner ear damage. My hearing diminished from playing in a local rock band in the 60, 70's in G-ville Fla.



Frequency , what frequency

 

[AcuDefTechGuy]

Maybe I should keep it < 90 dBC (instead of 97.5 dBC), which is probably < 80 dBA.

 

[Steve81]

Maybe I should keep it < 90 dBC (instead of 97.5 dBC), which is probably < 80 dBA.

Depends. Duration is of course the other half of the puzzle, and you mentioned that 97.5dB was the peak reading. If that's just a short term peak and average levels are much lower, there's probably not much to worry about.

 

[3db]

It may be a mistake to assume that exposure to a particular frequency or range of frequencies results with damage to those hair cells that respond to those frequencies.

I'm not at all familiar with what is known about this, but one thing seems to be clear. Damage to hearing begins with losses in the cells that respond to high frequencies. It seems to be caused by being exposed to loud sounds, but not necessarily loud high frequencies.

Loss of hearing can also be caused by other causes unrelated to loud sounds, such as long exposure to certain drugs.

I agree with you to air on the side of caution. However, I'm as curious as hell to find out if there is frequency based dependency on this .

 

[AcuDefTechGuy]

Depends. Duration is of course the other half of the puzzle, and you mentioned that 97.5dB was the peak reading. If that's just a short term peak and average levels are much lower, there's probably not much to worry about.

True. It ranges from 40-97.5 dBC, but average probably 80 dBC.

 

[Pyrrho]

OSHA does not recommend > 8 hrs exposure to 90dBA.

My peak SPL is only 82.5dBA (500Hz-10kHz).

But my peak SPL is also 97.5 dBC (mainly from the subwoofers).

I guess OSHA does not care about dBC?

They only care about dBA which covers 500Hz-10kHz?

They are far less concerned with other frequencies, because:

Hz (HERTZ) The unit measurement for audio frequencies. The frequency range for
human hearing lies between 20 Hz and approximately 20,000 Hz. The
sensitivity of the human ear drops off sharply below about 500 Hz and
above 4,000 Hz.​

http://www.cdc.gov/niosh/docs/96-110/pdfs/96-110.pdf

You might want to read that whole document, as well as:

http://www.cdc.gov/niosh/docs/98-126/pdfs/98-126.pdf
(especially chapter 4)

However, I don't think either will directly answer all of your questions.


Also, keep in mind that OSHA does not promise that you will not have hearing loss from noise at levels lower than their guidelines. They tell you that exceeding them will do damage, but that is not the same at all as saying that exactly following the guidelines is perfectly safe. In their own words (with emphasis added):

The National Institute for Occupational Safety and Health (NIOSH) has recommended that all worker exposures to noise should be controlled below a level equivalent to 85 dBA for eight hours to minimize occupational noise induced hearing loss.​

​

Safety and Health Topics | Occupational Noise Exposure

Notice, they do not claim that following their guidelines is adequate to prevent noise induced hearing loss, only that following the guidelines will "minimize" the damage, or in other words, do less damage than exceeding their recommended limits.

 

[gmichael]

What.......?

 

[AcuDefTechGuy]

The National Institute for Occupational Safety and Health (NIOSH) has recommended that all worker exposures to noise should be controlled below a level equivalent to 85 dBA for eight hours to minimize occupational noise induced hearing loss.

< 85 dBA seems more like it than 90 dBA.

My Max/Peak level was only 82.5 dBA, so 90 dBA would be crazy loud.

You guys should do the same experiment and see what you get as your Peak dBA & dBC.

 

[cpp]

< 85 dBA seems more like it than 90 dBA.

My Max/Peak level was only 82.5 dBA, so 90 dBA would be crazy loud.

You guys should do the same experiment and see what you get as your Peak dBA & dBC.

I say to everyone, turn it up loud and tell me in 10 or 20 years what its like. You only get a few chances to save your hearing and then that's it.


ADTG Now I know why you like measurements it's because your losing your hearing ,

 

[AcuDefTechGuy]

I say to everyone, turn it up loud and tell me in 10 or 20 years what its like. You only get a few chances to save your hearing and then that's it.


ADTG Now I know why you like measurements it's because your losing your hearing ,

So you think 82.5 dBA Peak is too loud?

What is your actual peak SPL when you listen?

And for the record, I like measurements and numbers because I have an "engineering mind"!

 

[Steve81]

And for the record, I like measurements and numbers because I have an "engineering mind"!

I like infomercials and reading claims from snake oil vendors. What does that say about my mind?

 

[AcuDefTechGuy]

I like infomercials and reading claims from snake oil vendors. What does that say about my mind?

Something else...