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Hearing EQ

JoachimStrobel

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(This Post was inspired by https://www.audiosciencereview.com/forum/index.php?threads/hearing-loss-a-hobby-fades-away.7316/)

A couple of weeks ago I embarked on a project that I like to share and ask for comments: Ear or Hearing EQ.
After having toyed with Room EQ, I thought it would be cool to have the DSP-EQ correct for my hearing deficiencies too: I am close to 60 and have a tinnitus.
And while I could of course get my last medical´s audiogram, I thought it would be better to measure my hearing in my room with my equipment and hence merge Room and Ear EQ.
The goal is the definition of a new room-curve, merging Toole´s with my hearing-deficiency.

My setup is a NanoAVR HDA-DL with DIRAC, an Umik-1 and a PC running the Dirac GUI and REW. The NanoAVR´s analog output feeds into an analog pre-amp that feeds 3*2ch amps. I have a 5.1 setup with all identical speakers but use only left and right at this time for measurements.

I have the UMIK pointing down on me, 20 cm above my head (using 90deg calibration) and run the REW Signal generator and the RTA display. I adjust the volume of my preamp to check my hearing threshold using discrete sine-waves from 20-18000hz in induvial steps. I note down the RTA DB Level when I start hearing the tone. Dirac is on but the filters are off, meaning for NANOAVR that the levels are still matched. I do this for the left and right ear separate and averaged, I move my head to catch high frequency beams. I invite my family and friends for this too. I average 3-5 measurments runs for plotting.
1572437579738.png


While I initially believed that my tinnitus is the problem, I discovered that there is more. At first I used the ISO 226-1987&2003 threshold data for comparison to make sure I do not measure nonsense. My low frequency hearing matched the ISO curves quite well. Above 10Khz it was different and probably reflects loudspeaker vs headphones and my age. And then I was surprised seeing my hearing response starting at 2 Khz stretching with a loss of 10 dB to 6 Khz. I measured young people and well-aged ones for comparison.

.
1572437721379.png

I searched the Internet and found literature that shows, that my hearing response seems to be not un-usual for my age group.
I could match my younger peer groups hearing to published 20-30 year´s hearing which gave me confidence that I am not measuring nonsense. I used that “20-30year” curve as a baseline where I like to correct my hearing to, and created a “difference” curve. I gave up measuring in the 2000-200 hz range as my room was too noisy (20-30dB) to really record the threshold there. Above 2 Khz and below 200 hz measurements seemed valid.
1572437862897.png


But I only measure the hearing threshold, not the effective hearing at 60-80 dB where I usually listen to music. I did not want to transfer my “difference” curve from the 20-25 dB threshold to my 80dB music world. I regressed a transfer function based on ISO226-2003 to shift from 20 to 80 dB and modified my "20 dB-difference" curve accordingly to a "80 dB-difference" curve. I looked into the problem, that those ISO curves were measured with young people and that these loudness responses change with age: there is one publication on that and this is for future enhancements…
1572437897612.png


I then subtracted the Toole room curve from my “difference” curve and used the results as new target curve in DIRAC (realizing that a room curve is probably “db”-sensitive too…). DIRAC cannot do magic and could be limited by the NanoAvr´s DSP implementation too. Checking with REW, I realized that I could not get Dirac to do any correction I wanted. The finesse in the 5-8Khz range could not be reproduced. So I overdid the complexity in the design not realising that the actual world is different. I went forth and back between Dirac and Rew to check the possibilities. DIRAC also checks what the speaker seems to be capable of and does not design a filter that seems to fall outside of the Speakers-comfort zone. And after I had modified my NanoAvr to Dirac, I sadly cannot simply go back and try some REW filters.
For the low frequency I am still not settled. I noticed that the perceived loudness difference between 100-60db quite closely matches Toole´s observation for untrained people – that sounded like a rational basis to do it and I use it but this is a bit bass-heavy. To be improved.
1572437941837.png


1572440225318.png


I then tried to create separate target curves for my left and right ear but am still working on that. My right speaker´s tweeter did not like my experiments with 16Khz at 85 dB, so there is now also a tinnitus build into my right speaker and I have to fix that first before fine tuning left and right.

The results – are great. Well, one could say lifting the mid-heights and the bass (as my workflow´s byproduct) always sounds nice and pleasant. The question could be asked if what I perceive as ”hearing as I where young” is simply an illusion. Sure. But nevertheless, I think it is fantastic, I do enjoy music played like that (my young peer groups thinks it is too bright) and believe that this sounds as I heard music many years ago. Again, could be an illusion but then it is a nice one.

I do believe that this method has a future: After doing room EQ, why not checking on the hearing of the user too and allow an option for “personal optimization”?Looking at the published data, many people above 45 years old suffer from a frequency response loss above 3Khz, the loss above 10khz is rather trival. So many people would benefit. And there might be even a market for a strong EQ-DSP and liquid cooled tweeters that could handle that..

The next goals is the head transfer function- my surround speakers are only 10-20deg behind my head, so they “shine” right onto my ear-drums. I notice that my hearing correction is too bright there as it was optimized for front left and right. And there is the center too.


Hoping for good comments.....


References:
F Toole: The Measurement and Calibration of Sound Reproducing Systems. J Audio Eng Soc, Vol 63, No 7/8, 2015
AR Valiente, AR Fidalgo, JR Garcia-Berrocal, RR Camacho: Hearing threshold for an ontologically screened population in Spain. International Journal of audiology, April 2015
K Kurakata, T Mizunami, K Matsushita: How much is the individual difference in hearing sensitivity. Acoust. Sci & Tech 34, 1 (2013)
H Moller, MF Sorensen, D Hammershoi, CB Jensen: Head-related transfer functions of human subjects. Journal of the Audio Engineering Society, 43(5), 1995.
https://www.nonoise.org/library/handbook/
 

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pozz

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I really appreciate the work and thought you put into this, so I'm sorry to say that the measurement technique and setup you're using will give you incredibly inaccurate results. You could easily be off by 20dB or more for any given frequency across the spectrum! I'm also not sure if I understood you correctly, but did you really blow the tweeter in one of your speakers?

Your line of thought follows some of the considerations that audiologists use to develop personalized hearing aids, but doesn't take into account the kinds of compensations required to adjust for the microphone, it's position in the room relative to you, your speakers (their frequency response and directivity), and finally your hearing. As you said, the volume at which you play will greatly affect the perceived loudness.

I would suggest reading the whole of this thread and then listening to some of the audiology/psychoacoustics lectures I posted here.

All that said, with some work and refinements you'll be able to put together a much better compensation curve. The main thing is to understand the limits and sensitivity of the techniques you're using, and once you do that it should all fall into place.
 

Berwhale

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@JoachimStrobel - I really appreciate the effort you've put into your measurements and the time you've spent documenting them to share with us. This is the kind of discussion that distinguishes ASR from other popular 'audiophile' forums and why i've enjoyed my relatively brief time here so much.
 
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JoachimStrobel

JoachimStrobel

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I really appreciate the work and thought you put into this, so I'm sorry to say that the measurement technique and setup you're using will give you incredibly inaccurate results. You could easily be off by 20dB or more for any given frequency across the spectrum! I'm also not sure if I understood you correctly, but did you really blow the tweeter in one of your speakers?

Your line of thought follows some of the considerations that audiologists use to develop personalized hearing aids, but doesn't take into account the kinds of compensations required to adjust for the microphone, it's position in the room relative to you, your speakers (their frequency response and directivity), and finally your hearing. As you said, the volume at which you play will greatly affect the perceived loudness.

I would suggest reading the whole of this thread and then listening to some of the audiology/psychoacoustics lectures I posted here.

All that said, with some work and refinements you'll be able to put together a much better compensation curve. The main thing is to understand the limits and sensitivity of the techniques you're using, and once you do that it should all fall into place.

Thanks for your comments, and yes, I was made aware about the limitation of my experiment very early already.

https://www.avnirvana.com/threads/sine-wave-level-check-for-hearing-test.5516/#post-44158

So, I did actually spent most time not with measuring but looking for published results to benchmark my measurements and manually digitizing them for comparison. As this is what every experimental data scientist needs to do – check own data versus other proven data.

And so I started with all the loudness curves, Fletcher-Munson, Stevens, Iso226-1987&2003. Below 400Hz all values fall nicely between the 0 and 20 db curves for all my measurements, telling me that this part is OK. The region between 0.5-4 Khz is difficult as the room´s noise level is above the hearing threshold for those frequencies. While the ear can still hear one specific frequency once trained for it, it is still an error prone measurement.
1572611096415.png

A 2khz Signal buried in Harmonics and noise

Real troublesome is the comparison above 4 Khz where large deviation between ISO-226 and my data exists. This has a lot to do with high frequency being close to focused beans once the emerge from my speaker and the angle that which they hit my eardrums makes a difference to the omnidirectional microphone response. And it was very insightful to see, that my young group did these high frequency measurements with speed and ease and were very reproducible while I struggled a lot depending how I skewed my head – saying that something in my ear is a bit broken as it is much more angle dependent than for a young ear.

But then one needs to look at all these loudness curves and recognizes, that they all differ from each other in that region, so this is where the experimental setup is important. I then look at available publication without paywall where hearing characteristics for different age groups are measured – I came across a Spanish and Japanese one. In particular the Spanish data fits perfectly to my young and old age group. I show the 20-30y curve, but the 55+y curve matches mine also very nicely. And then I basically used these type curves as bases. So from the many measurements I did for myself, I edited them as much as allowable to match the 55y type curve, and computed the difference to the 20-30y curve. And I believe that this is the strength of my method – I do not concentrate so much on individual measurements but try to align them with type curves. And then work from there. Hence more published data would be better (and I would seriously suggest that Stereophile companies acquire those as their typical age group will need such correction in most cases…). Therefore I am a bit stuck for my Tinnitus corrections as I do not have a type curve for that and have to 100% trust my data – which is troublesome.
1572611374129.png

Measurments over three days for one Person, left and right ear, showing the variations. The black curve is close the the 55+y curve from Spain and the 59y from Japan

But the biggest issue of course is the loudness adjustment. Very true, all this data is so far only valid for the hearing threshold, but not within the actual 80-60dB listening range.
For the moment I use the Iso226 curves to “translate” from 20 to 80 dB. This is flawed as we know that these loudness curves differ a lot, and because one publication point to the fact that these loudness curve are very age dependent too.

I did not really blew my tweeter. But I noticed that during the end of my experiments, where I did try to catch this 16Khz signal on the right ear that I sometimes heard and then not, that the frequency response of the right tweeter changed from the left one. And Dirac noticed that too and hence would block extensive gains for that frequency. I since then change the tweeter and all is good.

And to summarize, the goal is not to design a hearing aid. I hear well for my age group as seen through many medical exams. . And medical tests are also designed to avoid people claiming a hearing problem when there is None. But I have a dent in my hearing that makes my hearing different to my younger hearing and possibly to the audio engineer´s (even though Toole made some comments on that in his book). So my goal is to bring my convolved loudspeaker-room system to that level. And I try to do this by validating type curves that I select by comparison to my measurements. And having fun.
 

MRC01

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If we can't discover the fountain of youth, at least we can re-discover the sound of youth. With this EQ, if you go listen to a local concert of un-amplified acoustic music, it will sound different than it does when played back on your stereo.

Also, consider whether as our ears gradually lose acuity in high frequencies, our brain compensates in perception; think of it as a "brain-software" subconscious perceptual EQ boosting the treble. Decades ago, before the gradual hearing loss, your brain/perception wasn't doing that because it didn't have to. So if you restore the same FR curve, it may actually be perceptually brighter than it used to sound.
 

pozz

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Thanks for your comments, and yes, I was made aware about the limitation of my experiment very early already.

https://www.avnirvana.com/threads/sine-wave-level-check-for-hearing-test.5516/#post-44158

So, I did actually spent most time not with measuring but looking for published results to benchmark my measurements and manually digitizing them for comparison. As this is what every experimental data scientist needs to do – check own data versus other proven data.

And so I started with all the loudness curves, Fletcher-Munson, Stevens, Iso226-1987&2003. Below 400Hz all values fall nicely between the 0 and 20 db curves for all my measurements, telling me that this part is OK. The region between 0.5-4 Khz is difficult as the room´s noise level is above the hearing threshold for those frequencies. While the ear can still hear one specific frequency once trained for it, it is still an error prone measurement.
View attachment 37527
A 2khz Signal buried in Harmonics and noise

Real troublesome is the comparison above 4 Khz where large deviation between ISO-226 and my data exists. This has a lot to do with high frequency being close to focused beans once the emerge from my speaker and the angle that which they hit my eardrums makes a difference to the omnidirectional microphone response. And it was very insightful to see, that my young group did these high frequency measurements with speed and ease and were very reproducible while I struggled a lot depending how I skewed my head – saying that something in my ear is a bit broken as it is much more angle dependent than for a young ear.

But then one needs to look at all these loudness curves and recognizes, that they all differ from each other in that region, so this is where the experimental setup is important. I then look at available publication without paywall where hearing characteristics for different age groups are measured – I came across a Spanish and Japanese one. In particular the Spanish data fits perfectly to my young and old age group. I show the 20-30y curve, but the 55+y curve matches mine also very nicely. And then I basically used these type curves as bases. So from the many measurements I did for myself, I edited them as much as allowable to match the 55y type curve, and computed the difference to the 20-30y curve. And I believe that this is the strength of my method – I do not concentrate so much on individual measurements but try to align them with type curves. And then work from there. Hence more published data would be better (and I would seriously suggest that Stereophile companies acquire those as their typical age group will need such correction in most cases…). Therefore I am a bit stuck for my Tinnitus corrections as I do not have a type curve for that and have to 100% trust my data – which is troublesome.
View attachment 37528
Measurments over three days for one Person, left and right ear, showing the variations. The black curve is close the the 55+y curve from Spain and the 59y from Japan

But the biggest issue of course is the loudness adjustment. Very true, all this data is so far only valid for the hearing threshold, but not within the actual 80-60dB listening range.
For the moment I use the Iso226 curves to “translate” from 20 to 80 dB. This is flawed as we know that these loudness curves differ a lot, and because one publication point to the fact that these loudness curve are very age dependent too.

I did not really blew my tweeter. But I noticed that during the end of my experiments, where I did try to catch this 16Khz signal on the right ear that I sometimes heard and then not, that the frequency response of the right tweeter changed from the left one. And Dirac noticed that too and hence would block extensive gains for that frequency. I since then change the tweeter and all is good.

And to summarize, the goal is not to design a hearing aid. I hear well for my age group as seen through many medical exams. . And medical tests are also designed to avoid people claiming a hearing problem when there is None. But I have a dent in my hearing that makes my hearing different to my younger hearing and possibly to the audio engineer´s (even though Toole made some comments on that in his book). So my goal is to bring my convolved loudspeaker-room system to that level. And I try to do this by validating type curves that I select by comparison to my measurements. And having fun.
Of course, this is very interesting and is done in the name of fun:)

You can try to create your personal loudness curves this way: reposition your loudspeakers such that you don't have to turn your head to hear high frequencies. Set playback for a specific SPL. Take measurements across the audible spectrum with your microphone set at your ear level facing the speakers at the precise spot your head was located. Note them and repeat for different SPL levels, as high and as low as possible. (I'd emphasize that microphone positioning should be exact and always done at the same spot as your ears each time. Even a 2cm error makes a large difference in the results.)

With hearing loss, you'll find that you will be unable to create curves for lower SPL at some point. You can compare with younger/older people to see where this point lies instead of testing for thresholds, which would be more difficult.

If you already had an audiologist measure your hearing, you can compare the results up to 8kHz very accurately, but converting from dB HL (hearing level), which is set at the hearing threshold, and dB SPL.

This paper may be useful for interpretation of the results: Categorical loudness scaling and equal-loudness contours in listeners with normal hearing and hearing loss
 

Theriverlethe

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If we can't discover the fountain of youth, at least we can re-discover the sound of youth. With this EQ, if you go listen to a local concert of un-amplified acoustic music, it will sound different than it does when played back on your stereo.

Also, consider whether as our ears gradually lose acuity in high frequencies, our brain compensates in perception; think of it as a "brain-software" subconscious perceptual EQ boosting the treble. Decades ago, before the gradual hearing loss, your brain/perception wasn't doing that because it didn't have to. So if you restore the same FR curve, it may actually be perceptually brighter than it used to sound.

I totally I agree with this, from my own experience. I have mild hearing loss around 6kHz, but still find sibilance annoying at moderate or loud volume levels. I also still enjoy a Harman type curve with a high frequency roll-off. My suspicion is that the brain “EQ boosts” to compensate for lost hearing, once those frequencies cross the absolute threshold of perceptibility.
 
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JoachimStrobel

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If we can't discover the fountain of youth, at least we can re-discover the sound of youth. With this EQ, if you go listen to a local concert of un-amplified acoustic music, it will sound different than it does when played back on your stereo.

Also, consider whether as our ears gradually lose acuity in high frequencies, our brain compensates in perception; think of it as a "brain-software" subconscious perceptual EQ boosting the treble. Decades ago, before the gradual hearing loss, your brain/perception wasn't doing that because it didn't have to. So if you restore the same FR curve, it may actually be perceptually brighter than it used to sound.

Three options there:
Yes, the brain compensates and all is fine. People with expensive audio equipment like that option.
No, it does not compensate, or only badly. No good.
It compensates for some time but after a couple of years needs to be reminded how it did sound....

Listening to real music is a challenge. Now I know that I miss something. However, seeing the instruments seems to give the brain an extra intensive for its reconstruction business, so it is not as bad as without visuell feedback.
 

pozz

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So a parametric EQ boost is not what's happening. The image below shows graphs for hearing loss of 0dB, 20dB, 40dB and 60dB HL.

JASMAN-000137-001899_1-g008.jpg

With age, the effects are most noticeable at the threshold of hearing for the quietest sounds and with declining sensitivity to high frequencies (both of which are part of typical audiometric tests). But the changes are more fundamental, and have to do with perception of loudness overall (and this kind of testing is done only in research settings).

What's experienced is level-dependent sensitivity changes. As you get older the filter characteristics of the ear change and broaden. Because of this, more frequencies will fall into the same critical band and so certain ranges will feel louder than before. Once mapped, it will appear as if the equal-loudness curves have been compressed. The SPL-to-phon ratio is what's being affected.

Briefly, if you play bandpassed noise which stays within a single critical band you will experience a specific loudness level. You can broaden or narrow the bandwidth of the noise and compensate the amplitude per frequency such the overall power level and consequently the perception of loudness will remain the same. However, once the noise bandwidth is broadened beyond the critical band, even after compensating for amplitude, you will experience a subjective increase in loudness.

So with playback current hardware applies the same level of gain to each frequency without level compensation. Given the compression of loudness curves, it means that the dynamic changes in music are much too broad. This means that older folks may prefer more compressed music given that the level changes will stay within a more narrow band on average. This may also explain the preference for tube electronics (not because of added distortion, which can affect loudness perception as well, particularly for the highs) but because tubes dynamically compress signals.

@JoachimStrobel is entirely right when he says that the industry should move toward creating equipment that is able to compensate for subjective loudness at different volume levels, much of which will include modifying existing parts to make sure they are rugged enough to handle individual perceptual requirements.

What this all translates to is that you'll need greater overall boost at low levels to achieve the same relative loudness across the spectrum and experience relatively normal hearing at louder levels, although the distance between what constitutes "low" and "normal" has shrunk.
 

Theriverlethe

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So a parametric EQ boost is not what's happening. The image below shows graphs for hearing loss of 0dB, 20dB, 40dB and 60dB HL.

View attachment 37760
With age, the effects are most noticeable at the threshold of hearing for the quietest sounds and with declining sensitivity to high frequencies (both of which are part of typical audiometric tests). But the changes are more fundamental, and have to do with perception of loudness overall (and this kind of testing is done only in research settings).

What's experienced is level-dependent sensitivity changes. As you get older the filter characteristics of the ear change and broaden. Because of this, more frequencies will fall into the same critical band and so certain ranges will feel louder than before. Once mapped, it will appear as if the equal-loudness curves have been compressed. The SPL-to-phon ratio is what's being affected.

Briefly, if you play bandpassed noise which stays within a single critical band you will experience a specific loudness level. You can broaden or narrow the bandwidth of the noise and compensate the amplitude per frequency such the overall power level and consequently the perception of loudness will remain the same. However, once the noise bandwidth is broadened beyond the critical band, even after compensating for amplitude, you will experience a subjective increase in loudness.

So with playback current hardware applies the same level of gain to each frequency without level compensation. Given the compression of loudness curves, it means that the dynamic changes in music are much too broad. This means that older folks may prefer more compressed music given that the level changes will stay within a more narrow band on average. This may also explain the preference for tube electronics (not because of added distortion, which can affect loudness perception as well, particularly for the highs) but because tubes dynamically compress signals.

@JoachimStrobel is entirely right when he says that the industry should move toward creating equipment that is able to compensate for subjective loudness at different volume levels, much of which will include modifying existing parts to make sure they are rugged enough to handle individual perceptual requirements.

What this all translates to is that you'll need greater overall boost at low levels to achieve the same relative loudness across the spectrum and experience relatively normal hearing at louder levels, although the distance between what constitutes "low" and "normal" has shrunk.

Very interesting post. Doesn’t a lot of current hardware already have DRC? What about noise, rather than age-related hearing loss? My “friend” can hear 2kHz at 0dB, but has a 40-50dB threshold at 6kHz.
 

pozz

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Very interesting post. Doesn’t a lot of current hardware already have DRC? What about noise, rather than age-related hearing loss? My “friend” can hear 2kHz at 0dB, but has a 40-50dB threshold at 6kHz.
Thanks.

Are those dB SPL or dB HL? And are they his audiometric results?

Age-related hearing loss will show up in bone conduction tests (using an oscillator pressed on the mastoid area of the skull, which bypasses the outer and middle ear), and will have a similar slope as tests made using acoustic/air conduction (through headphones). Heightened thresholds due to noise-induced hearing damage tend to be centered around 4kHz, and will show up on the audiogram with air conduction but not bone conduction.

As far as I know DRC works according to a predefined curve. There's no feedback loop which samples acoustic performance continually adjusts levels for loudness. @mitchco will know for sure.
 
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Theriverlethe

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Thanks.

Are those dB SPL or dB HL? Are these his audiometric results?

Age-related hearing loss will show up in bone conduction tests (using an oscillator pressed on the mastoid area of the skull, which bypasses the outer and middle ear), and will have a similar slope as tests made using acoustic/air conduction (through headphones). Heightened thresholds due to noise-induced hearing damage tend to be centered around 4kHz, and will show up on the audiogram with air conduction but not bone conduction.

As far as I know DRC works according to a predefined curve. There's no feedback loop which samples acoustic performance continually adjusts levels for loudness. @mitchco will know for sure.
Audyssey Dynamic Volume changes the curve based on the volume setting, but I doubt it does any real-time analysis of the input signal.

Hmmm, his chart says dB HTL. 6kHz threshold is about 40dB and 4kHz is around 30dB HTL. He should probably have a more professional screening than is provided by his employer.
 

pozz

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Interesting. Still, the DRC would have to be able to calibrated according to your individual loudness perception (which is uncorrelated to electric/digital signal level). It becomes kind of like EQing headphones at that point.

H(T)L is probably hearing (threshold) level. 0dB HL is different for each frequency, and is set according to the lowest curve of the well-known equal loudness curves, which are in dB SPL. 40dB HL is considered moderate hearing loss. If the audiometric curve is shaped like this the hearing loss is noise-induced:

afp20130101p41-f3.gif

Edit: I plucked that chart from Google but didn't notice at first that bone conduction (<, [ ) is similar to air conduction (X, O). This means that hearing loss is sensorineural, which happens with exposure to sudden extremely loud sounds. This particular audiogram was that of a patient who served in the infantry: https://www.aafp.org/afp/2013/0101/p41.html

I should have said that long term noise-induced hearing loss will show a clearer mismatch between air and bone conduction with that sort of shape.
 
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Theriverlethe

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Interesting. Still, the DRC would have to be able to calibrated according to your individual loudness perception (which is uncorrelated to electric/digital signal level). It becomes kind of like EQing headphones at that point.

H(T)L is probably hearing (threshold) level. 0dB HL is different for each frequency, and is set according to the lowest curve of the well-known equal loudness curves, which are in dB SPL. 40dB HL is considered moderate hearing loss. If the audiometric curve is shaped like this the hearing loss is noise-induced:

View attachment 37775

Similar shape, but not as extreme, and the center frequency is 6kHz instead of 3kHz. The “summary” says mild high pitch hearing loss, so it’s unclear to me if HL and HTL are the same thing. There’s also a gray shaded are showing “norms,” presumably based on age.
 

RayDunzl

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As far as I know DRC works according to a predefined curve. There's no feedback loop which samples acoustic performance continually adjusts levels for loudness.


Mine takes my curve preference, and creates a static filter.

The FR is the same for volume changes at the signal level.

I have a Dynamic EQ available in a DEQ2496, but didn't find it useful. Could try again.



I set the DRC up using 80dB tone (pretty loud), and typically play music that registers (LEQ) a few dB below to a few dB above that average level, yielding 95 to 105dB peak.

1572810976191.png
1572811592152.png



That, by way of "it just turns out that way", puts me in the "flat" zone of Fletcher Munson (blue), though I seem to be lacking per ISO (red).

I tried imitating the ISO curve and didn't like what I heard with music.

It may be because the bass (player's level) is already adjusted to be heard within the recording by the creators - just my impression.

I don't find the bass lacking at lower levels, and besides, wouldn't that would be a natural consequence of listening at a lower level?

I don't attempt to make any adjustment for my hearing loss, as it is fruitless. My deficiency is more like brickwall than rolloff.

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Sounds natural to me, nobody complains, so, there you have it.
 
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pozz

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Similar shape, but not as extreme, and the center frequency is 6kHz instead of 3kHz. The “summary” says mild high pitch hearing loss, so it’s unclear to me if HL and HTL are the same thing. There’s also a gray shaded are showing “norms,” presumably based on age.
Those tests only go up to 8kHz, and they're really meant for speech. He might have trouble with hearing consonants.
 

pozz

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@RayDunzl It's not surprising re: your preference. The ISO curves are averages after all. And then when you're measuring in-room it's not comparable to measuring at your eardrum. It makes sense to use mostly low-Q adjustments anyway, unless we're talking bass correction.
 

Theriverlethe

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Those tests only go up to 8kHz, and they're really meant for speech. He might have trouble with hearing consonants.

The “mild hearing loss” assessment is probably based on the 30dB number at 4kHz. I’m not sure they even include 6kHz in that kind of assessment.
 

pozz

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The “mild hearing loss” assessment is probably based on the 30dB number at 4kHz. I’m not sure they even include 6kHz in that kind of assessment.
Wow. Well, they have to be done in semi-anechoic conditions anyway, otherwise the results can be really misleading.
 
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