Max volume headphones and safety

[Bliman]

Hi,
A short time ago I was listening with my headphones (beyerdynamic dt250) connected to my computer by the grace design headphone amplifier.
Now the knob of the amplifier doesn't behave so good anymore (Grace says it is the controller I think that is getting old). But to make a long story short. I was listening to music and turned the knob and the volume flew in the 90's. And I got a sound blast. I immediately set the headphones of my ears.
Since then I am worried about my hearing.
Now I read about the safe listening db.
But how do you know easy without a real spl meter the db you are listening?
I downloaded decibel x on my phone and sandwiched my phone microphones between my headphone. But I have no clue if it is accurate. It was around 80 db.
Does anybody have a suggestion how to do it correctly but easy? Or was my method good enough?
Thank you

 

[solderdude]

with the amp severely clipped theoretically you could have received about 127dB SPL.
Not clipped about 124dB.

These are peak values though which means when listening to music average levels be 15 to 20dB lower and when measured in Phon (what an SPL meter does in A-weighting) then it could give readings of around 25dB lower so say 100dB average at full blast (not yet clipping).
Safety regulations say you are allowed to endure 100dB average for 15 minutes (hairdryer close to your head).

When the amp was severely clipping maybe the average levels could have been 115dB average (doubt it would be clipping that much) and even that is considered 'safe' for about 20 seconds which is very long when having that on your head.

To measure SPL in a headphone you would have to seal the microphone all around the cups otherwise the readings will be off considerably.

 

[Bliman]

with the amp severely clipped theoretically you could have received about 127dB SPL.
Not clipped about 124dB.

These are peak values though which means when listening to music average levels be 15 to 20dB lower and when measured in Phon (what an SPL meter does in A-weighting) then it could give readings of around 25dB lower so say 100dB average at full blast (not yet clipping).
Safety regulations say you are allowed to endure 100dB average for 15 minutes (hairdryer close to your head).

When the amp was severely clipping maybe the average levels could have been 115dB average (doubt it would be clipping that much) and even that is considered 'safe' for about 20 seconds which is very long when having that on your head.

To measure SPL in a headphone you would have to seal the microphone all around the cups otherwise the readings will be off considerably.

First thank you for answering.
I can totally sandwich the cups together with the smartphone flat between them and on the side of the microphones. I tried it on the song where I got the blast and I got a reading of 105.2 db max.
Now that I did the test I heard a click in the amplifier around volume 90 (I don't know what that means). Also on the specs of the headphone there states 100 SPL.
I find these charts so misleading https://www.cm.be/gezond-leven/lichaam/oren/decibelschaal

 

[solderdude]

There are indeed some questionable descriptions in there such as 'Opgefokte iPod, fuif'
The question with music is whether it concerns average levels or peak levels.

The question is whether the smartphone measures peak levels or average levels, A or C weighted etc.

The specs of the headphone ar 101dB/mW (measured) = 108dB/V.
The amp can deliver 6V so add 15dB = 123dB

 

[Bliman]

There are indeed some questionable descriptions in there such as 'Opgefokte iPod, fuif'
The question with music is whether it concerns average levels or peak levels.

The question is whether the smartphone measures peak levels or average levels, A or C weighted etc.

The specs of the headphone ar 101dB/mW (measured) = 108dB/V.
The amp can deliver 6V so add 15dB = 123dB

Yikes 123 dB. So would the Headphone stop at 108dB/V?
I just see it on the app now. It gives the reading in Z.
Sorry for being a noob.

 

[solderdude]

The efficiency rating is merely indicating how loud the headphone plays when 1mW is applied (@ 500Hz or 1kHz) which is the dB/mW number.
The dB/V number indicates how loud the headphone plays when 1V is applied.
These are not maximum or minimum numbers ... just a reference that can be used to calculate levels when output powers (in a certain impedance) or output voltages are known.

 

[Bliman]

The efficiency rating is merely indicating how loud the headphone plays when 1mW is applied (@ 500Hz or 1kHz) which is the dB/mW number.
The dB/V number indicates how loud the headphone plays when 1V is applied.
These are not maximum or minimum numbers ... just a reference that can be used to calculate levels when output powers (in a certain impedance) or output voltages are known.

Ah ok thank you.
Is a measure in Z good or has it to be in A? And does 105.2 dB sound realistic to you?

 

[solderdude]

Z-weighting is 'linear', there is no curve and for lower frequencies no clear 'relation' with perceived loudness.

One also needs to know if the measured levels are peak or average. There can be substantial differences between peak and average.

 

[Bliman]

Z-weighting is 'linear', there is no curve and for lower frequencies no clear 'relation' with perceived loudness.

One also needs to know if the measured levels are peak or average. There can be substantial differences between peak and average.

If I read correctly A weighting better correlates how the ears hear. https://www.cirrusresearch.co.uk/blog/2011/08/what-are-a-c-z-frequency-weightings/. But does that mean that the Z one is useless?
The meter decibel x (app) shows max and average. But I think your peak and average mean something else.
It is frustrating that you can't know what decibels you are listening to. There is so many material for protecting your ears and such and how much decibels to listen to. And that you have to watch out with your headphones, but there doesn't seem an easy way to know at what level you are listening to.

 

[solderdude]

Max = peak so it measures peak and average SPL.
Normal listening levels (average) are around 70dB average. Loud listening is around 80dB average.
Peaks can reach well over 100dB and won't damage your hearing that quickly.

 

[Bliman]

Max = peak so it measures peak and average SPL.
Normal listening levels (average) are around 70dB average. Loud listening is around 80dB average.
Peaks can reach well over 100dB and won't damage your hearing that quickly.

Yeah it measures peaks. And it got peaks of 105 dB when I tested the song at 99 volume level. I shall have to let my ears checked. Because somethings changed. But I don't know if it was from the incident. It was literally just a second or so.

 

[Cortes]

All the headphone amplifiers I've heard I'm sure will kill the hearing moving the knob at half position long enough. I've never understood the need of power in headphone amplifiers.

 

[solderdude]

A short peak of 120dB is not going to damage your ears. Prolonged exposure will.
Energy in music is spread over a wide frequency range anyway with the majority of the energy in the lows and lower mids.
The nominal power rating of the DT250 is 100mW, peak power will only have been 150mW or so which such a driver can handle easily for a few seconds with music.

105dB peaks are quite normal for a still comfortably loud listening level.
You should probably read this

When you listen to music at comfortable levels where you don't feel the urge to dial down you do not need to worry about using headphones.

I do worry about some kids with IEM's or closed headphones that you can hear a meter away.

When you felt pain in your ear and maybe ringing let your hearing be checked.

 

[Bliman]

A short peak of 120dB is not going to damage your ears. Prolonged exposure will.
Energy in music is spread over a wide frequency range anyway with the majority of the energy in the lows and lower mids.
The nominal power rating of the DT250 is 100mW, peak power will only have been 150mW or so which such a driver can handle easily for a few seconds with music.

105dB peaks are quite normal for a still comfortably loud listening level.
You should probably read this

When you listen to music at comfortable levels where you don't feel the urge to dial down you do not need to worry about using headphones.

I do worry about some kids with IEM's or closed headphones that you can hear a meter away.

When you felt pain in your ear and maybe ringing let your hearing be checked.

I feel something on my ears. But it is strange. A sort of hollowness. I want to thank you for trying to explain it to me. I am afraid that I don't have the knowledge to follow. I read your page and I see things like comfortable listening level and such. But I think that this is different for everyone. And is so vague because I can't measure it. I have the meter here lying and the only thing that is making a sound is the humming of the computer. And it gives a reading around 50dB with peaks going to 63dB when I type.
But when I sandwich it between the headphones and set it to the listening level I listen at around 72. It is no quite and the meter gives around 70-75dB when listening to music.

 

[solderdude]

These levels are correct. Set it to A-weighting and the 'quite room' levels should be lower.
Listening around 70-75dB are 'normal' listening levels which one can listen to the whole day long.
In the evening this level is loud enough, during the day it is on the lower side of loud enough.

 

[Sergei]

I feel something on my ears. But it is strange. A sort of hollowness. I want to thank you for trying to explain it to me. I am afraid that I don't have the knowledge to follow. I read your page and I see things like comfortable listening level and such. But I think that this is different for everyone. And is so vague because I can't measure it. I have the meter here lying and the only thing that is making a sound is the humming of the computer. And it gives a reading around 50dB with peaks going to 63dB when I type.
But when I sandwich it between the headphones and set it to the listening level I listen at around 72. It is no quite and the meter gives around 70-75dB when listening to music.

There are multiple mechanisms by which the hearing acuity can be destroyed by excessively loud music. For instance:

(1) Mechanical breakage of "ionic valves" on inner hair cell protruding Stereocilia (hairs). May happen in milliseconds. Yet it mostly recovers in two weeks, and usually completely recovers in two months, due to a nano-repair mechanism.

If you limit your exposure to loud sounds for two weeks, and after that no longer feel the "hollowness" you described, or other unnatural sensations, then that's what most likely happened. Just to be safe in this case, continue limiting your exposure for six more weeks, and then you shall be fine.

(2) Systematic long overload of the synaptic interface between the inner hair cells and auditory nerve fibers. This one causes so called Hidden Hearing Loss. This condition has been largely unrecognized till about a decade ago. Its recognition led to more restrictive limits on loud sounds exposure. Solderdude gave an excellent advice compatible with this more recent framework: disregard the formerly considered safe limit of 85 dB SPL, and use 75 dB instead.

(3) Pathological changes in the inner hair cells themselves, typically brought about by systematic long overload at SPL of 95+ dB, typical of dance clubs and audiophile showrooms. Exposure to frequencies around 100 Hz at SPL of around 100 dB creates a sensation of bodily motion in humans, because such sound excites Vestibular System. A thrill generated by a loud car or motorcycle engine is due to the same mechanism. Avoid those, as you would avoid hard drugs. It is just not worth it!

 

[Bliman]

These levels are correct. Set it to A-weighting and the 'quite room' levels should be lower.
Listening around 70-75dB are 'normal' listening levels which one can listen to the whole day long.
In the evening this level is loud enough, during the day it is on the lower side of loud enough.

I have bought the app. And now I can set it to A weighted and it is around 3 dB less then Z weighted.
When I measure it in A and set it at my usual level which is not really soft. And it gives me a reading of around 73dB.
And I could listen to around avg 68.4dB all day with a max around 76dB. But I will say it does sound much more direct on headphones so I don't know if I could listen to it all day.
While when I talk about 30 cm from my phone and it goes to 75dB and it doesn't sound as hard as my headphone music.
The only thing that is difficult to know if what my phone is hearing when I sandwich it is the same as what my ears are hearing it.
Do you think my method is a solid enough method?

 

[Bliman]

There are multiple mechanisms by which the hearing acuity can be destroyed by excessively loud music. For instance:

(1) Mechanical breakage of "ionic valves" on inner hair cell protruding Stereocilia (hairs). May happen in milliseconds. Yet it mostly recovers in two weeks, and usually completely recovers in two months, due to a nano-repair mechanism.

If you limit your exposure to loud sounds for two weeks, and after that no longer feel the "hollowness" you described, or other unnatural sensations, then that's what most likely happened. Just to be safe in this case, continue limiting your exposure for six more weeks, and then you shall be fine.

(2) Systematic long overload of the synaptic interface between the inner hair cells and auditory nerve fibers. This one causes so called Hidden Hearing Loss. This condition has been largely unrecognized till about a decade ago. Its recognition led to more restrictive limits on loud sounds exposure. Solderdude gave an excellent advice compatible with this more recent framework: disregard the formerly considered safe limit of 85 dB SPL, and use 75 dB instead.

(3) Pathological changes in the inner hair cells themselves, typically brought about by systematic long overload at SPL of 95+ dB, typical of dance clubs and audiophile showrooms. Exposure to frequencies around 100 Hz at SPL of around 100 dB creates a sensation of bodily motion in humans, because such sound excites Vestibular System. A thrill generated by a loud car or motorcycle engine is due to the same mechanism. Avoid those, as you would avoid hard drugs. It is just not worth it!

Thank you for the advice.

 

[solderdude]

I have bought the app. And now I can set it to A weighted and it is around 3 dB less then Z weighted.
When I measure it in A and set it at my usual level which is not really soft. And it gives me a reading of around 73dB.
And I could listen to around avg 68.4dB all day with a max around 76dB. But I will say it does sound much more direct on headphones so I don't know if I could listen to it all day.
While when I talk about 30 cm from my phone and it goes to 75dB and it doesn't sound as hard as my headphone music.
The only thing that is difficult to know if what my phone is hearing when I sandwich it is the same as what my ears are hearing it.
Do you think my method is a solid enough method?

You need not worry about a few dB's difference in methods.

When you play your phone at normal levels and measure at 30 cm it is a LOT less louder than your voice at 30cm.
Measure your voice at 2cm distance and see how high the SPL meter rises ... just for fun.

Just play music at for you comfortable levels. Get your amp fixed or replaced so it doesn't go loud suddenly (sounds like a defect in the ground contact of the volume control)

 

[Bliman]

You need not worry about a few dB's difference in methods.

When you play your phone at normal levels and measure at 30 cm it is a LOT less louder than your voice at 30cm.
Measure your voice at 2cm distance and see how high the SPL meter rises ... just for fun.

Just play music at for you comfortable levels. Get your amp fixed or replaced so it doesn't go loud suddenly (sounds like a defect in the ground contact of the volume control)

Grace says that it is the encoder (whatever that means) is worn. Luckily I have a remote that I can change the volum with. And with that it doesn't happen.
Just to be clear I was just talking about talking in the microphone of the smartphone at a distance of around 30cm. That gave a reading around 75dB.
While the music through the headphone at this level is fairly loud (and louder than my talking) when sandwiched between my headphone.