How do we measure...?

[DrJohnRead]

Can we measure such things as...

 

leading and trailing edges of music and identify harshness vs decay vs airiness and spacious?

 

music playback signal speed and determine if it’s right or accurate or correct?

 

Pre and post signal ringing and then it’s level in relationship with hearing and perceived audio quality?

 

soundstage? And it’s dimensions?

 

Ok these kick off a brainstorm on the Agenda for developing measurement technology and practice.

 

If you some answers that will be great. If you have more questions please feel free and add them.

 

[John Dyson]

On 5/6/2020 at 8:57 PM, DrJohnRead said:

Can we measure such things as...

 

leading and trailing edges of music and identify harshness vs decay vs airiness and spacious?

 

music playback signal speed and determine if it’s right or accurate or correct?

 

Pre and post signal ringing and then it’s level in relationship with hearing and perceived audio quality?

 

soundstage? And it’s dimensions?

 

Ok these kick off a brainstorm on the Agenda for developing measurement technology and practice.

 

If you some answers that will be great. If you have more questions please feel free and add them.

 

Your question shows an example as to why it is tricky to discuss these things.   Specifically, speaking of pre and post ringing...  Most of the time, when speaking of brickwall filters and minimum phase/linear phase filtering, those aren't really ringing, but are Gibbs effect.  True ringing usually from energy storage like with a high Q filter.

 

What is pre and post ringing?  What is Gibbs effect?   Gibbs effect is where a composite waveform like a square wave has part of its frequency components removed, therefore leaving left over residual signal or 'wobbles' in the signals.  That is, the wobbles that you see result from a mix of missing sine waves (frequency components.)   Most often, Gibbs effect describes chopping off the higher frequency components of a square wave or similar, therefore leaving the left over residue 'wobbles'  because of cumulative missing sine-wave components making up that 'square wave'. 

 

Why do the wobbles (residues) seem to move around, look like they are in different places on a minimum phase vs linear phase filter?  It is because the timing of the frequency components (phase) is different for different frequencies.   A linear phase filter will have constant delay vs frequency.  A minimum phase (or not linear-phase) will have different delays for different frequencies, so lower frequencies will be delayed differently (time wise) than higher frequencies.  This will make the residual 'wobbles' look different on different filter types on a time domain display.

 

Why can a linear phase vs. not-linear phase filter sound different?  If the filter is long enough (has enough taps/delay), then the timing for the various frequency components can be very significant.  There might be other effects also -- I am not a hearing expert, but the signals ARE different because the timing is different.

 

John

 

[Audiophile Neuroscience]

On 5/7/2020 at 10:57 AM, DrJohnRead said:

Can we measure such things as...

No

"Not everything that can be counted counts and not everything that counts can be counted."

[Allan F]

12 hours ago, Audiophile Neuroscience said:

"Not everything that can be counted counts and not everything that counts can be counted."

 

Definitely.

[Speedskater]

On 5/8/2020 at 7:10 AM, Audiophile Neuroscience said:

No

"Not everything that can be counted counts and not everything that counts can be counted."

But everything that counts can be heard in ears only listening tests.

[bluesman]

2 hours ago, Speedskater said:

But everything that counts can be heard in ears only listening tests.

But to objecti-fi this, you need to measure the auditory function of those ears, because very few will function identically.  That requires measuring cochlear, retrocochlear and central audition, including but not limited to frequency dependent threshold sensitivity, recruitment, tone decay, discrimination, maximum comfortable loudness, and many other parameters.  There are research tests for everything from phase discrimination to minimum audible frequency differences. We use none of them.  And even if we did, one shot testing is insufficient - we need to quantify intertest variance at both short (ie immediate retest) and long intervals (eg every week).
 

For our purposes, the standard audiological test range of 250-8kHz is grossly inadequate. But good extended range testing equipment is largely limited to academic and subspecialty neuro-otologic practices and facilities. Internet auditory testing calibrated by approximating the loudness of rubbing your fingers together is as crude as wax cylinder recordings.

 

Routine hearing testing is simply not useful except to detect gross hearing abnormalities and otologic disease.  The fact that some of us hear what others don’t is not at all surprising and we are not using the tests that could help explain it objectively. Being told your hearing is “normal” on the basis of routine audiologic evaluation means little or nothing to an audiophile. Gross hearing loss (eg threshold sensitivity below -30 dB anywhere in the 250-8k range) should be evident without testing to most (if not all) experienced audiophiles.  And even this deficiency (which is the most common one identified by audiologists as hearing loss) may not impair functional audition and the ability to hear “everything that counts” if it’s the only abnormality - you’d just have to turn up the volume and adapt to a nonlinear frequency-sensitivity function, eg with EQ.

 

So everything that counts will only be audible to those who can hear it - and that’s much more objective than to most seem to believe. Perhaps a good audiology setup would even be a better use of funds for some than 6 figure speakers......

[Speedskater]

It matters not, how good a listener's hearing is. If a listener can hear a difference in an ears only listening test, then they are free to have a hearing preference.

And in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear. This was demonstrated with MEGP3 type data compression. When normal hearing masking frequencies were diminished by irregular frequency response curves.   

[bluesman]

50 minutes ago, Speedskater said:

It matters not, how good a listener's hearing is. If a listener can hear a difference in an ears only listening test, then they are free to have a hearing preference.

And in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear. This was demonstrated with MEGP3 type data compression. When normal hearing masking frequencies were diminished by irregular frequency response curves.   

So what you meant was that everything that counts to a given listener can be heard through his or her ears.  Your generalization is what prompted my response, because everything that counts to you and is audible to you may not encompass what counts to me and is audible to me.  

[bluesman]

2 hours ago, Speedskater said:

This was demonstrated with MEGP3 type data compression. When normal hearing masking frequencies were diminished by irregular frequency response curves.   

Please provide a reference for this.  As a physician, I’m both data driven and evidence based. But you’ve offered neither to support your statement that “...in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear”. What are the hearing problems? What are the differences? What’s the study design? How big is the study cohort? 

 

As one of my specialty board certifications is Otolaryngology, I’m quite familiar with the literature on this topic as well as the spectrum of clinical observations reported. There are several excellent explanations of MPEG (which is what I assume you mean by MEGP3) out there, starting with this from the University of Washington and several similar treatises on MPEG and the nonlinearity of human hearing. But I’ve never seen a published study of the effects of any kind of hearing loss on compression-dependent differentiation of any specific auditory parameter related to listening to music.

 

Please help me learn about this.

[Audiophile Neuroscience]

9 hours ago, Speedskater said:

But everything that counts can be heard in ears only listening tests.

Totally disagree that "everything that counts can be heard in ears only listening tests." This can only occur if you show evidence that those listening tests are reliable and valid, discount the science of false negatives, presume to know what counts for somebody else, and you have the means to count it.

[Audiophile Neuroscience]

3 hours ago, bluesman said:

Please provide a reference for this.  As a physician, I’m both data driven and evidence based. But you’ve offered neither to support your statement that “...in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear”. What are the hearing problems? What are the differences? What’s the study design? How big is the study cohort? 

....So everything that counts will only be audible to those who can hear it - and that’s much more objective than to most seem to believe. Perhaps a good audiology setup would even be a better use of funds for some than 6 figure speakers......

 

 

Hi Prof Bluesman,

I agree but would simply additionally offer that apart from hearing it, one also needs to be able to perceive it. IOW intact peripheral and central auditory processing doesn't guarantee perception in some cases. We know of the role of training in listening skills but in the medical world the example of looking at an MRI scan, the trained eye 'sees' so much more.

I am also reminded of when i was a medical student and unable to 'hear' (perceive) subtle cardiac murmurs using a stethoscope despite my documented excellent hearing. My "half deaf" cardiologist tutor could describe diastolic "whiffs" of sound with uncanny accuracy as verified with later imaging.By the time I became a registrar (senior house doctor in USA terms?) I too could 'hear' and identify those cardiac murmurs in what was previously just a jumbled blob of sound.

[bluesman]

28 minutes ago, Audiophile Neuroscience said:

 

Hi Prof Bluesman,I agree but would simply additionally offer that apart from hearing it, one also needs to be able to perceive it.

True - but Speedskater’s statement is about hearing audible differences.  You can only hear a difference if you perceive it as a difference, which is why you and I had to learn to listen for murmurs.  We didn’t know what to listen for until we were taught to ignore what we already heard and listen for what we were overlooking.  Once we knew what to listen for, we found it.

 

I assume you used the standard scale for loudness of heart murmurs.  A grade 1 murmur is one only heard by an attending cardiologist. Grade 2s are audible to noncardiac attendings and cardiac fellows. Grade 3s can also be heard by residents, and grade 4 murmurs are audible even to medical students.  For you nonphysicians, that’s an old medical school joke - but it’s strangely relevant to this discussion.  There are many studies comparing sensitivity and specificity of electronic to acoustic stethoscopes, and skilled ears are generally as good with either one despite amplification in the electronic versions. This one found no statistically significant differences for most murmurs for both fellows and attending cardiologists. They knew what they were listening for, so they found it - when it was there.

[fas42]

Us humans have excellent listening skills - a lifetime of constantly processing sounds impinging on our ears, and relating that to what we can see happening, etc, means that we can easily distinguish sounds that are "natural" from those that are "artificial". Which is why if we are in a room where sounds of musical instruments are coming from some non-visible source, it's trivially easy to decide whether it's the real thing, or merely audio playback. Most times, 🙂.

 

If we want to measure how closely sound reproduction matches the genuine article - which seems a reasonable goal, to me - we need to understand what triggers the ear/brain uses to determine a success/failure result. IME it's how well the fine detail is resolved, the 'resolution' of the system that matters - just having "lots of detail" is not the point; that detail must be very clearly reproduced - meaning low distortion - especially when the overall envelope of the waveform is quite vigorous.

[Audiophile Neuroscience]

1 hour ago, bluesman said:

I assume you used the standard scale for loudness of heart murmurs.  A grade 1 murmur is one only heard by an attending cardiologist. Grade 2s are audible to noncardiac attendings and cardiac fellows. Grade 3s can also be heard by residents, and grade 4 murmurs are audible even to medical students.  For you nonphysicians, that’s an old medical school joke - but it’s strangely relevant to this discussion.

 

Yes Indeed, these golden ears attending cardiologists were typically also audiophiles ! 😁

[John Dyson]

16 hours ago, bluesman said:

Please provide a reference for this.  As a physician, I’m both data driven and evidence based. But you’ve offered neither to support your statement that “...in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear”. What are the hearing problems? What are the differences? What’s the study design? How big is the study cohort? 

 

As one of my specialty board certifications is Otolaryngology, I’m quite familiar with the literature on this topic as well as the spectrum of clinical observations reported. There are several excellent explanations of MPEG (which is what I assume you mean by MEGP3) out there, starting with this from the University of Washington and several similar treatises on MPEG and the nonlinearity of human hearing. But I’ve never seen a published study of the effects of any kind of hearing loss on compression-dependent differentiation of any specific auditory parameter related to listening to music.

 

Please help me learn about this.

I have an anecdote (personal experience) about a temporary hearing loss appeared to make it easier to detect certain defects.   My hearing problem was related to a 'bug', and result in some strange hearing oddities.  I didn't fully quantify them (of course, not qualified), but did notice that part of the defect was a severe dip in sensitivity at certain frequencies.

 

Defects in the quality from my audio processing project became very obvious.  Specifically, the reveal was easier detection of lower midrange (like below 1kHz) intermodulation.  The IMD/MD became as clear as day -- yet normally it requires extreme concentration to hear the problem, detecting design changes in the dynamics processing.  (This is at a relatively fine grained layer of quality -- most consumer recordings are full of intermodulation and terrible distortions.)

 

This is NOT a controlled observation, but just something that I noticed.  I did take advantage of that insight into the recording quality, and staying very aware of the improvement that was easier to make.

 

Another anecdote, this one is about MP3.  Normally, I don't reliably hear mp3 issues at higher rates (256k -> 320k).   Earlier in development, my software had an odd defect that caused lots of fast/little discrete moduations in the audio.  The normal perception of the bug was a seeming improvement in clarity -- but of course, the modulations were a significant defect.   MP3 had troubles transparently handling the distorted material -- it appeared to be a time resolution issue.

 

Unfortunately, for my project, I don't have 'golden ears', and my hearing repeatably changes through the day, and diminishes in acuity vs. fatigue.   After lots of whack a mole games, nowadays, I seldom trust the accuracy/repeatability of my hearing.  I KNOW that it will mislead me much of the time.

 

John

 

[pkane2001]

17 hours ago, bluesman said:

Please provide a reference for this.  As a physician, I’m both data driven and evidence based. But you’ve offered neither to support your statement that “...in some situations, a listener with serious medical hearing problems can hear differences that a listener with good hearing won't hear”. What are the hearing problems? What are the differences? What’s the study design? How big is the study cohort? 

 

As one of my specialty board certifications is Otolaryngology, I’m quite familiar with the literature on this topic as well as the spectrum of clinical observations reported. There are several excellent explanations of MPEG (which is what I assume you mean by MEGP3) out there, starting with this from the University of Washington and several similar treatises on MPEG and the nonlinearity of human hearing. But I’ve never seen a published study of the effects of any kind of hearing loss on compression-dependent differentiation of any specific auditory parameter related to listening to music.

 

Please help me learn about this.

 

Don't have a reference for MPEG3 study like this, but have looked into various auditory impairments in my research into hearing and HRTF (all done for fun, none professionally and no medical certifications).

 

The obvious disease that could have an impact on the 'audiophile' audibility claims is hyperacusis. Although not very common, it results in extreme sensitivity to certain frequencies compared to others (eg, high frequencies) and makes the perception of certain amplitude variations much more pronounced compared to others. I can see how hyperacusis could affect someone's perception of MP3 or similar codecs that are targeting a 'normal' sound perception by shifting the frequency balance into regions where hyperacusis might be much more sensitive and the codec much less accurate or detailed.

 

Would like to hear your professional opinion.

 

 

[bluesman]

1 hour ago, pkane2001 said:

Don't have a reference for MPEG3 study like this.

That’s because there aren’t any, at least any indexed in Medline or any other literature database accessible through my university’s library.  Hyperacusis (which is not a disease - it’s a symptom complex that has no known pathological correlate and no objective, measurable diagnostic criteria) has been the subject of many articles.  But there are no objective studies of the auditory function of those who claim to have the symptoms.  In most of the scholarly works on this, the major contributing factors were felt to be cognitive reactions, actionable or somatic behavior, and emotional factors. This 2003 paper is an excellent discussion despite being 17 years old. Here’s the current ASHA page on it, which is both consistent with and supportive of the lack of objective correlates.

 

Some people who complain that normal environmental sounds are uncomfortably loud have an underlying disorder of which sound sensitivity is one symptom, eg Lyme Disease, multiple sclerosis, and isolated disorders of the seventh cranial nerve like herpes zoster infection.  The only correlates in those without demonstrable disease (which is many if not most) are to fatigue, depression, stress, and anxiety in the many subjective studies in the literature.  
 

I suppose it’s possible that someone with truly heightened sensitivity to specific frequencies could hear anomalies inaudible to those with normal hearing. But without objective data on both that person’s auditory function and the phenomenon of interest, accepting such reports would require enough blinded testing and comparisons of that person’s perception to confirm that the reported perceptions are accurate beyond random chance.

 

The other problem with your concept is that those target frequencies may be generated not by the equipment or software and may not be in the source.  Auditory pathology is well known to cause frequency perception aberrations, and those alleged codec flaws may be artifactual distortions caused by cochlear or retrocochlear dysfunction. One example of this is diplacusis, in which a pure tone of known frequency is perceived correctly by one ear but as a different frequency by the other.

[pkane2001]

27 minutes ago, bluesman said:

That’s because there aren’t any, at least any indexed in Medline or any other literature database accessible through my university’s library.  Hyperacusis (which is not a disease - it’s a symptom complex that has no known pathological correlate and no objective, measurable diagnostic criteria) has been the subject of many articles.  But there are no objective studies of the auditory function of those who claim to have the symptoms.  In most of the scholarly works on this, the major contributing factors were felt to be cognitive reactions, actionable or somatic behavior, and emotional factors. This 2003 paper is an excellent discussion despite being 17 years old. Here’s the current ASHA page on it, which is both consistent with and supportive of the lack of objective correlates.

 

Some people who complain that normal environmental sounds are uncomfortably loud have an underlying disorder of which sound sensitivity is one symptom, eg Lyme Disease, multiple sclerosis, and isolated disorders of the seventh cranial nerve like herpes zoster infection.  The only correlates in those without demonstrable disease (which is many if not most) are to fatigue, depression, stress, and anxiety in the many subjective studies in the literature.  
 

I suppose it’s possible that someone with truly heightened sensitivity to specific frequencies could hear anomalies inaudible to those with normal hearing. But without objective data on both that person’s auditory function and the phenomenon of interest, accepting such reports would require enough blinded testing and comparisons of that person’s perception to confirm that the reported perceptions are accurate beyond random chance.

 

The other problem with your concept is that those target frequencies may be generated not by the equipment or software and may not be in the source.  Auditory pathology is well known to cause frequency perception aberrations, and those alleged codec flaws may be artifactual distortions caused by cochlear or retrocochlear dysfunction. One example of this is diplacusis, in which a pure tone of known frequency is perceived correctly by one ear but as a different frequency by the other.

 

Thank you. I have no preconceived notions about whether this is real or not. The fact that auditory pathology can result in exaggerated sensitivity to higher frequencies might explain how this might work.  As a starting conjecture, this seems plausible to me, but I have no way to study this having no access to people with Hyperacusis.

[DrJohnRead]

Thank you for such replies to my topic here. I’m astonished at the level of experience brought to this matter. Truly enlightening.

 

Part of the reasons for my raising this topic is that (I feel) we are hardly moving the needle on objective study of hearing and measurements in Hi-Fi. 
 

Of course I’m chasing an area here of applied research that lacks key drivers say health, profit or other key sources of support. It’s a hobby industry only, despite the industry global reach it’s a relatively low level of capitalization. Even as a luxury segment it can’t compete with diamonds watches or boats.

 

Yet students at institutions like Berkeley College of Music in CA could stand studying and some moving into research in this field. I know there are some who do.

 

Here’s some research on the phenomenon of cueing. Perhaps this may have inflow onto the tuning of focus towards cardiac signals mentioned earlier.

 

Specifically, in marketing there is a well used audio cuing process to awaken attention. Typically advertising uses this for tv and radio advertisements to wake people’s brains up from idle to receive the information provided.

 

i suggest this is related to an overall sensitivity to change in auditory signals. I suggest this ability has survival value. Of course, like every ability, there are individual and class or group differences such as cardiologists who can discriminate certain audio signals from background noise.

 

In sum, it appears we have not scoped the key constructs, their definitions or created measures for a large part of critical Hi-Fi performance. And as a result we spend lots of time arguing over topics for which we don’t have epistemological control or language for. 
 

Amusingly we routinely put down attempts to raise such topics by those committed to the present rather than build a progressive agenda for expanding our knowledge in areas currently poorly researched measured defined and so on.
 

Thank you again to everyone who has contributed here so far.

 

I live in hope. The attached refers.

 

 

[fas42]

36 minutes ago, DrJohnRead said:

In sum, it appears we have not scoped the key constructs, their definitions or created measures for a large part of critical Hi-Fi performance. And as a result we spend lots of time arguing over topics for which we don’t have epistemological control or language for. 
 

Amusingly we routinely put down attempts to raise such topics by those committed to the present rather than build a progressive agenda for expanding our knowledge in areas currently poorly researched measured defined and so on.
 

 

In part this is because there is a need to believe that an audio replay chain "adds" to what's on the recording; that, somehow, there is some magical behaviour that means the more expensive and ambitious the playback rig is, the better a recording can be made to sound. The whole industry is built around this concept; and part of this belief system is that there is a natural divide between "good" and "bad" recordings - the more "accomplished" the components are, the more obvious is the separation between these two quality levels.

 

Everything in my experience says this is wrong thinking - what's on the recording is the determining factor, and the only criteria that matter are measures that determine how far what one subjectively perceives differs from what a "perfect" playback would deliver. How I work with that in my own audio adventures is to be critical of any audible anomalies which are clearly characteristics of the playback chain - and work to remove them ... the result of doing that is a particular recording "always sounds the same" - which of course is how it should be, if the replay chain is doing its job well enough.

 

This means, for example, that a CD I bought 30 years ago, and played on a competent rig I had back then, has the same presentation, evokes the same sense of the musical event captured, on my current, cheap, active speakers - in spite of the technology used in the two instances being very, very different ... this is applying the principle that the mind very strongly reacts, and responds to aspects of an audible event that distinguish it from any previous exposure - these are the variables that need to brought under control, if one wants to have some certainty that the hifi performance is up to the mark.

[Teresa]

20 hours ago, fas42 said:

In part this is because there is a need to believe that an audio replay chain "adds" to what's on the recording...

 

No one believes this. Audio equipment can only subtract from what is on the recording. The only thing audio equipment can add is distortion.

 

20 hours ago, fas42 said:

...there is some magical behavior that means the more expensive and ambitious the playback rig is, the better a recording can be made to sound.

 

Or correctly stated the more accurate an audio system is more of the recording will be revealed, good or bad.

 

20 hours ago, fas42 said:

The whole industry is built around this concept; and part of this belief system is that there is a natural divide between "good" and "bad" recordings - the more "accomplished" the components are, the more obvious is the separation between these two quality levels.

 

This is true. Generally great sounding recordings are made in excellent recording spaces by recording engineers who's goal is to capture the music as accurately as possible. Poor recordings are not.

[Audiophile Neuroscience]

On 5/11/2020 at 10:18 PM, pkane2001 said:

The obvious disease that could have an impact on the 'audiophile' audibility claims is hyperacusis. Although not very common, it results in extreme sensitivity to certain frequencies compared to others (eg, high frequencies) and makes the perception of certain amplitude variations much more pronounced compared to others. I can see how hyperacusis could affect someone's perception of MP3 or similar codecs that are targeting a 'normal' sound perception by shifting the frequency balance into regions where hyperacusis might be much more sensitive and the codec much less accurate or detailed.

 

Would like to hear your professional opinion.

 

 

 

 

On 5/12/2020 at 12:13 AM, bluesman said:

 Hyperacusis (which is not a disease - it’s a symptom complex that has no known pathological correlate and no objective, measurable diagnostic criteria) has been the subject of many articles.  But there are no objective studies of the auditory function of those who claim to have the symptoms.  In most of the scholarly works on this, the major contributing factors were felt to be cognitive reactions, actionable or somatic behavior, and emotional factors. This 2003 paper is an excellent discussion despite being 17 years old. Here’s the current ASHA page on it, which is both consistent with and supportive of the lack of objective correlates.

 

Some people who complain that normal environmental sounds are uncomfortably loud have an underlying disorder of which sound sensitivity is one symptom, eg Lyme Disease, multiple sclerosis, and isolated disorders of the seventh cranial nerve like herpes zoster infection.  The only correlates in those without demonstrable disease (which is many if not most) are to fatigue, depression, stress, and anxiety in the many subjective studies in the literature.  
 

 

I think we need to be a little careful here as people with the symptom hyperacusis are likely a heterogeneous group.

 

Loudness intolerance may occur in Migraine and is usually referred to as phonophobia and the related light intensity intolerance as photophobia. More broadly Loudness intolerance or hyperacusis is associated with many conditions and sometimes idiopathic. In either case the mechanism may be unclear .

 

My understanding is that hyperacusis occurs across the frequency range although there are examples of frequency specific conditions like autism

 

The most controversial are people reporting painful intolerance to otherwise non painfully loud stimuli.This is getting more into my area. Allodynia is pain due to a stimulus that does not normally provoke pain. It is a well recognized neurological phenomenon  and there has been much research into peripheral and central sensitization mechanisms

 

The simplest form of plasticity in nervous systems is that repeated stimulation may lead to habituation (decreased response) or sensitization (increased response)  Prolonged or strong activity may  lead to increased neuronal responsiveness or central sensitization Neuroplasticity and subsequent CNS sensitization include altered function of chemical, electrophysiological, and pharmacological systems and exaggerated perception of stimuli as well as perception of innocuous stimuli as painful (allodynia)

 

Audiometric Characteristics of Hyperacusis Patients (2015) found "that LDLs are decreased across the full range of audiometric frequencies, regardless of the pattern or degree of hearing loss, indicates that hyperacusis might be due to a generalized increase in auditory gain". This would be consistent with allodynia research......."A recent neuroimaging study has reported increases in sound-evoked neuronal responses in the auditory midbrain, thalamus, and cortex of subjects with hyperacusis. Such increases in sound-evoked neuronal activation might reflect increased neuronal response gain, which has been proposed as a putative mechanism for hyperacusis"

 

The whole story remains not totally clear and as with most things perceptual, psychogenic influences are also present.

 

 

[pkane2001]

3 hours ago, Audiophile Neuroscience said:

 

 

 

I think we need to be a little careful here as people with the symptom hyperacusis are likely a heterogeneous group.

 

Loudness intolerance may occur in Migraine and is usually referred to as phonophobia and the related light intensity intolerance as photophobia. More broadly Loudness intolerance or hyperacusis is associated with many conditions and sometimes idiopathic. In either case the mechanism may be unclear .

 

My understanding is that hyperacusis occurs across the frequency range although there are examples of frequency specific conditions like autism

 

The most controversial are people reporting painful intolerance to otherwise non painfully loud stimuli.This is getting more into my area. Allodynia is pain due to a stimulus that does not normally provoke pain. It is a well recognized neurological phenomenon  and there has been much research into peripheral and central sensitization mechanisms

 

The simplest form of plasticity in nervous systems is that repeated stimulation may lead to habituation (decreased response) or sensitization (increased response)  Prolonged or strong activity may  lead to increased neuronal responsiveness or central sensitization Neuroplasticity and subsequent CNS sensitization include altered function of chemical, electrophysiological, and pharmacological systems and exaggerated perception of stimuli as well as perception of innocuous stimuli as painful (allodynia)

 

Audiometric Characteristics of Hyperacusis Patients (2015) found "that LDLs are decreased across the full range of audiometric frequencies, regardless of the pattern or degree of hearing loss, indicates that hyperacusis might be due to a generalized increase in auditory gain". This would be consistent with allodynia research......."A recent neuroimaging study has reported increases in sound-evoked neuronal responses in the auditory midbrain, thalamus, and cortex of subjects with hyperacusis. Such increases in sound-evoked neuronal activation might reflect increased neuronal response gain, which has been proposed as a putative mechanism for hyperacusis"

 

The whole story remains not totally clear and as with most things perceptual, psychogenic influences are also present.

 

 

 

Interesting. The descriptions I found were related to increased sensitivity to specific (usually higher) frequencies. But it makes sense that hyperacusis might be more of a neuropathic type response. Some interesting studies show that it is more common with musicians, those exposed to loud sounds (I assume as is all hearing damage). Drummers apparently more susceptible than others. This shows why that might be:

 

 

I'm glad I only play a solo piano

 

[pkane2001]

On 5/11/2020 at 6:49 PM, DrJohnRead said:

Thank you for such replies to my topic here. I’m astonished at the level of experience brought to this matter. Truly enlightening.

 

Part of the reasons for my raising this topic is that (I feel) we are hardly moving the needle on objective study of hearing and measurements in Hi-Fi. 
 

Of course I’m chasing an area here of applied research that lacks key drivers say health, profit or other key sources of support. It’s a hobby industry only, despite the industry global reach it’s a relatively low level of capitalization. Even as a luxury segment it can’t compete with diamonds watches or boats.

 

Yet students at institutions like Berkeley College of Music in CA could stand studying and some moving into research in this field. I know there are some who do.

 

Here’s some research on the phenomenon of cueing. Perhaps this may have inflow onto the tuning of focus towards cardiac signals mentioned earlier.

 

Specifically, in marketing there is a well used audio cuing process to awaken attention. Typically advertising uses this for tv and radio advertisements to wake people’s brains up from idle to receive the information provided.

 

i suggest this is related to an overall sensitivity to change in auditory signals. I suggest this ability has survival value. Of course, like every ability, there are individual and class or group differences such as cardiologists who can discriminate certain audio signals from background noise.

 

In sum, it appears we have not scoped the key constructs, their definitions or created measures for a large part of critical Hi-Fi performance. And as a result we spend lots of time arguing over topics for which we don’t have epistemological control or language for. 
 

Amusingly we routinely put down attempts to raise such topics by those committed to the present rather than build a progressive agenda for expanding our knowledge in areas currently poorly researched measured defined and so on.
 

Thank you again to everyone who has contributed here so far.

 

I live in hope. The attached refers.

 

 

 

The topic of how we hear what we hear is a really complex one. There's the hearing apparatus itself - the ear. As any transducer, it has limitations on what it can and cannot detect, and this ability is not infinite, as well as not linear. The studies of hearing thresholds is complicated by the fact that this transducer is attached to a brain, that does a whole lot more non-linear processing of the incoming, detected signal, mixing it with information coming from both, short- and long-term memory, overlaying it with the current mental state, applying inherited and learned heuristic processing to extract relevant information from it, generalizing, and classifying it, and ultimately resulting in some form of recognition and conscious detection. What we hear is the result of this complex processing, and not what actually enters the ear.

 

While the transducer part (the ear) varies between individuals, the processing is even more dependent on individual brain structures, constructs, and memories. We all hear differently and the information we extract from the sound is different as well. It's possible to study multiple individuals and to then derive averages and distributions from such groups. But, in general, as @SoundAndMotion would say, it all depends

 

 

[Audiophile Neuroscience]

17 hours ago, pkane2001 said:

 

Interesting. The descriptions I found were related to increased sensitivity to specific (usually higher) frequencies.

 

I think it becomes difficult to interpret sometimes and make causal connections. IIRC about 2/3 of hyperacusis sufferers have some HF loss but eg in older populations the latter is not uncommon

"With an increase in high-frequency hearing loss, LDLs are also slightly increased in the hearing loss region, albeit to a much smaller degree than the HTs. Moreover, especially the LDL values at 6 kHz were almost identical for the three different degrees of hearing loss, showing that in this case, hearing loss can be ruled out as a determining factor for hyperacusis."

 

 

17 hours ago, pkane2001 said:

But it makes sense that hyperacusis might be more of a neuropathic type response.

 

That seems to be the working hypothesis and makes sense to me

 

17 hours ago, pkane2001 said:

Some interesting studies show that it is more common with musicians, those exposed to loud sounds

 

Loudness exposure is cited "as a major cause of hyperacusis" but it would appear independent of hearing loss damage.It may be brought on by repeated loud exposure or a single very loud noise.