Those of you who believe measurements aren't the whole story, do you have a hypothesis why that is?

[atmasphere]

I think it's naïve to believe that all science has been discovered. We are making new discoveries about science and the human body every day. We just don't hear with the resolution that the measurements show. There are just so many variables that it's really, really hard to know what one person is actually hearing vs another.

Human hearing perceptual rules are surprisingly consistent from one person to another across the entire population, honed by millions of years. That is why its possible to use deciBels to describe sound pressure, why masking made mp3s possible and so on. Its true that we have things to learn about our hearing perception, but its not a good idea to suggest that one person hears differently from another unless their hearing is compromised for purposes of furthering a conversation like this.

 

[atmasphere]

That may be true for a lab use amplifier like the Kronhite models, but I doubt if that level of engineering is applied to consumer audio tube amplifiers.

IME you are 100% correct

 

[lashto]

First, the authors consider 'ultrasounds' to start at 8 kHz. That certainly isn't what we mean here at ASR

Second, they summarize reports that if truly high frequency (17kHz and up -- which even then includes the audible range) sounds are present at quite elevated levels, damage results.

But that's not what you get in home audio, unless you like hearing damage.

You are grasping at straws.

I posted 2 entire fields of medical science for infrasonics and one metastudy for ultrasonics. And you are nitpicking on 1-2 examples which may not be 100% clear/applicable. But I am the one "grasping at straws"

And that nitpicking doesn't seem to be quite right either.
The ultrasound definition depends on country/regulations and the studies mostly split it as:

high audible frequency range (8–20 kHz) and the low-frequency ultrasonic range (20–50 kHz).

Yes you are right, some studies used "quite elevated levels" like 124dB. So waht? It does not mean that a lower level is healthy/enjoyable/desirable. Besides, some studies confirmed the effects as low as 75dB with just a few minutes of exposure:

...exposed 10 workers for 2 min to noise emitted by ultrasonic washers ... level over 75 dB(A) caused annoyance and discomfort.

P.S.
And if you properly read the study and followed some of the references, you may have found another surprise about that "audible range". ASR is quite scrupulous about it being 20Hz-20kHz and anything above 20kHz is considered unheard-of and not credible (see the recent thread about audible filter differences). Apparently that is not right either:

Hearing thresholds for pure tones above 16kHz

Hearing thresholds for pure tones between 16 and 30kHz were measured by an adaptive method. The maximum presentation level at the entrance of the outer ear was

pubs.aip.org

Table 1 is quite interesting:

• 32 young ears tested, 19-25 years old.
• 29 of 32 heard 20 kHz .. some at the very low level of 66dB!
• 16 (50%) heard 24 kHz
• 3 (9%) were even able to hear 28 kHz

... and all that at levels (mostly) below 100dB

Looks like ASR's definition for the audible range also needs an update. To about 30kHz. Or we keep talking about 15kHz max becuase audio is only for old/deaf farts like most of us

 

[atmasphere]

And if you properly read the study and followed some of the references, you may have found another surprise about that "audible range". ASR is quite scrupulous about it being 20Hz-20kHz and anything above 20kHz is considered unheard-of and not credible (see the recent thread about audible filter differences). Apparently that is not right either:

Hearing thresholds for pure tones above 16kHz

Hearing thresholds for pure tones between 16 and 30kHz were measured by an adaptive method. The maximum presentation level at the entrance of the outer ear was

pubs.aip.org

Table 1 is quite interesting:

• 32 young ears tested, 19-25 years old.
• 29 of 32 heard 20 kHz .. some at the very low level of 66dB!
• 16 (50%) heard 24 kHz
• 3 (9%) were even able to hear 28 kHz

... and all that at levels (mostly) below 100dB

Looks like ASR's definition for the audible range also needs an update. To about 30kHz. Or we keep talking about 15kHz max becuase audio is only for old/deaf farts like most of us

When I was going to college and working at Allied Radio Shack's service department, I could hear the ultrasonic motion alarm which I had to turn off as soon as I got into the building. It ran at 25KHz and it was painful. I was 22 at the time.

 

[krabapple]

I posted 2 entire fields of medical science for infrasonics and one metastudy for ultrasonics. And you are nitpicking on 1-2 examples which may not be 100% clear/applicable. But I am the one "grasping at straws"

And that nitpicking doesn't seem to be quite right either.
The ultrasound definition depends on country/regulations and the studies mostly split it as:

except, it would be absurd to class 20-50Hz sounds as inaudible. Just as it is absurd to call >8kHz inaudible.

These are not the frequencies that psychoacoustics says are inaudible. IOW your authors are not talking about what we are talking about here

Clearly the 'ultrasound' review authors are dealing with standard 'hearing test' ranges, what you get when you see an ear doctor. Not the limits of human hearing. THere is no other plausible reason for calling them 'ultrasounds'.

Yes you are right, some studies used "quite elevated levels" like 124dB. So waht? It does not mean that a lower level is healthy/enjoyable/desirable. Besides, some studies confirmed the effects as low as 75dB with just a few minutes of exposure:

Really? It is very common for things to be unnoticeable, harmless or even beneficial to humans at one level, and be toxic/harmful at a higher level. Even H2O fits the bill.

P.S.
And if you properly read the study and followed some of the references, you may have found another surprise about that "audible range". ASR is quite scrupulous about it being 20Hz-20kHz and anything above 20kHz is considered unheard-of and not credible (see the recent thread about audible filter differences). Apparently that is not right either:

'ASR' is not 'scrupulous' about that, as ASR 'understands' that the standard cited range is 20-22kHz, with uppermost reaches being far more likely to be audible to young ears than adult, and possibly even extending a few Hz beyond 22.

Ashihara's work is hardly unknown to those of us who've been fielding 'ultrasonic hearing' claims for decades, which cohort doesn't include you, apparently. He is actually more famous for debunking claims of ultrasonic hearing. He wasn't concerned with what audiophile claims, he was concerned with possibly harmful effects of very high frequency noise as per health department exposure recommendations.

Please review the Ashihara paper and tell us how its protocol supports audiophile claims of hearing 'ultrasonics'. Or simply acknowledge that results from synthesized single frequency sinusoid (a 'pure tone') blasted at >91dB (the 87dB result was for a 22kHz pure tone..which is not 'ultrasonic' by standard definition) directly at a listener's ear from either a Pioneer 'supertweeter' or a Denon loudspeaker* ~1.5 ft away, with a separate pink noise masking output coming from a speaker in front of him, don't necessarily track to what we hear listening at home. As so often the case, what human can hear under lab conditions doesn't necessarily tell us what an audiophile does hear from his setup.


*Ashihara doesn't detail which results came from which speaker setup

 

[lashto]

except, it would be absurd to class 20-50Hz sounds as inaudible.

I can surely agree with that. My point actually goes way beyond: IMO inaudible is a 'false' threshold because sound is a whole-body experience and inaudible is not the same as effect-less.

As for the rest, I normally enjoy some nitpicking but not in the mood today.
You are highly welcome to find one study/etc that shows the benefic or enjoyable effects of listening to ultrasounds. Particularly the kind which are generated by whatever electronics (and were not in the recording).
Or one study that says it is "safe" to not care about anything above ~15kHz (which appears to be a pretty widespread ASR 'consensus' lately).

In the meantime, everything I found goes pretty strongly in the opposite direction:

Ultrasound is acoustic energy that interacts with human tissues, thus, producing bioeffects that may be hazardous, especially in sensitive organs (i.e., brain, eye, heart, lung, and digestive tract)...

 

[Cbdb2]

I can surely agree with that. My point actually goes way beyond: IMO inaudible is a 'false' threshold because sound is a whole-body experience and inaudible is not the same as effect-less.

As for the rest, I normally enjoy some nitpicking but not in the mood today.
You are highly welcome to find one study/etc that shows the benefic or enjoyable effects of listening to ultrasounds. Particularly the kind which are generated by whatever electronics (and were not in the recording).
Or one study that says it is "safe" to not care about anything above ~15kHz (which appears to be a pretty widespread ASR 'consensus' lately).

In the meantime, everything I found goes pretty strongly in the opposite direction:

Strawman! That study is about ultrasound machines used in medical diagnostics and has nothing to do with hearing or hifi.

 

[lashto]

Strawman! That study is about ultrasound machines used in medical diagnostics and has nothing to do with hearing or hifi.

interesting.
Judging by the title, the authors seem to think that it's about the "biological effects of acoustic energy". I would say that hearing, hifi and music are also about "acoustic energy" .. about 99.99%.
And it's just a review/resume of ~150 studies. Not sure which one of those 150 did seem 'wrong' to you .. but I guess some of them may be upsetting for some people.

 

[Cbdb2]

Its a study on using high spl >2Mhz ultrasound in medical imaging, which has NOTHING to do with hifi.

 

[egellings]

interesting.
Judging by the title, the authors seem to think that it's about the "biological effects of acoustic energy". I would say that hearing, hifi and music are also about "acoustic energy" .. about 99.99%.
And it's just a review/resume of ~150 studies. Not sure which one of those 150 did seem 'wrong' to you .. but I guess some of them may be upsetting for some people.

The acoustic energy could be of a nonmusical, unpleasant nature with enough intensity to affect the body upon which it impinges.

 

[krabapple]

I can surely agree with that. My point actually goes way beyond: IMO inaudible is a 'false' threshold because sound is a whole-body experience and inaudible is not the same as effect-less.

No, SOME sounds CAN be a "whole body experience". It really depends on frequency and level.

I can surely agree with that. My point actually goes way beyond: IMO inaudible is a 'false' threshold because sound is a whole-body experience and inaudible is not the same as effect-less.

As for the rest, I normally enjoy some nitpicking but not in the mood today.
You are highly welcome to find one study/etc that shows the benefic or enjoyable effects of listening to ultrasounds. Particularly the kind which are generated by whatever electronics (and were not in the recording).

How about ones that show no effect at all....when listened to at typical home audio levels. That would be your studies.

Again, your data is about 'ultrasounds' at high levels. And again, no one said something that is routinely harmless can't be made harmful.

You are chasing things that are phantasms in home audio.

 

[lashto]

No, SOME sounds CAN be a "whole body experience". It really depends on frequency and level.

sorry, do not agree.
Any sound (=vibration) is a whole-body experience. It goes through your whole body and has effects on every single cell and atom (ok, listening to HPs is somewhat less than whole body).
The only question is if any of those effects are worth discussing. IMO, yes. All of them. And it's not just a me-oppinion, there are hundreds/thousands of related studies.

How about ones that show no effect at all....when listened to at typical home audio levels. That would be your studies.

In order to "show no effect at all" you have to study it first. And in spite of the thousands of studies, there is still a giant lot left to do. Particularly for the "no effect at all" aspect which is the hardest (borderline impossible) to prove.

About the effects in the hifi domain, someone else had a nice bottom line: any (extra) sound generated by the playback electronics is "sound I did not pay for". Off with it, please.

Again, your data is about 'ultrasounds' at high levels. And again, no one said something that is routinely harmless can't be made harmful.

no matter how many "again" you post, the linked data/studies are about both ultrasound and infrasound. About anything outside 20Hz-20kHz. And in many cases inside too. About high/uncommon levels. And about levels as low as 75dB. And even levels waaay lower than that .. like the level of natural vibration in living cells and organs.

P.S. and the same goes for @Cbdb2's post above who I guess is trying to be particularly 'funny' with that "it's a study about 2MHz" when I actually linked several hundreds of studies that cover a 0Hz to xGHz spectrum .. and have a particular focus on lower infrasonics and lower ultrasonics.

 

[solderdude]

What arrives at the ears and what the brain makes of that is always very different from the actual recorded waveform.
We can accurately describe and measure the electrical wave form right up to the electro-acoustic conversion.
After that it becomes a crap-shoot that can sound like anything between total crap and heavenly depending on way too many factors.

 

[lashto]

You are chasing things that are phantasms in home audio.

Am I really?

All good DAC/amp/etc builders are going to great lengths to filter/minimize the amount of those "sounds I did not pay for". Are they "chasing phantasms" too?
Since it is usually hard/impractical to completely eliminte those "extras", they do stop at some level and tell us "listen to this, it is fine". And we are supposed to just believe that. Well, I do not.

Don't care if you are a manufacturer of DACs or amps or power supplies or cables or ...
You should actually measure/investigate those things. Or at least do some reading/research. And give us more of "the whole story", not just "don't worry, it's safe". Messages like that and the "stop looking at it" attitude only make me worry more.

Am I right? Don't know.
But I will surely worry less if I see signs of adressing these aspects (more) seriously. Just do more to get rid of those "sounds I did not pay for", please. Keep trying to get rid of them fully. Or even better, build/invent devices that do not produce any. It's the only way to be sure

P.S.
this may seem offtopic for some but IMO it is full on. I haven't seen full-body-experience measurements anywhere in audio and that is a full chapter missing from "the whole story".

 

[solderdude]

Even if one would build an ideal playback system... the recordings still aren't, transducers still aren't, acoustics still aren't, ears still aren't and then the brain also interprets whatever arrives in a certain way.
Good enough (electrically) is good enough and usually is much better than acoustic events.

 

[lashto]

Even if one would build an ideal playback system... the recordings still aren't, transducers still aren't, acoustics still aren't, ears still aren't and then the brain also interprets whatever arrives in a certain way.
Good enough (electrically) is good enough and usually is much better than acoustic events.

I can easily understand that it is all very complex, very hard and very expensive (to improve, investigate...)

However, I am not on board with the "good enough" attitude. I want more, I want better, I want to see scientists/manufacturers/etc with an yes-we-can attitude. People who do not only investigate/fix issues that we are aware of, but also some that we are not (and hopefully do not charge an arm and a leg for it.)

More generally ... sending messages like "it's good enough"/"it's perfect"/"no worries"/etc to manufacturers is against my interests as a consumer/buyer. All you get from that attitude are higher prices for "the same sh*t in a different box".

 

[Jim Taylor]

I can easily understand that it is all very complex, very hard and very expensive (to improve, investigate...)

However, I am not on board with the "good enough" attitude. I want more, I want better, I want to see scientists/manufacturers/etc with an yes-we-can attitude. People who do not only investigate/fix issues that we are aware of, but also some that we are not (and hopefully do not charge an arm and a leg for it.)

More generally ... sending messages like "it's good enough"/"it's perfect"/"no worries"/etc to manufacturers is against my interests as a consumer/buyer. All you get from that attitude are higher prices for "the same sh*t in a different box".

I believe that this stage of the game is simply jousting at windmills, so to speak.

Scientists learn - sometime slowly - about the deleterious effects of various phenomena. But to do so, they build on the collective information of different disciplines in proportion to their applicability. Radiometry has little to do with acoustics, and acoustics has little to do with nuclear physics. (Not nothing at all, but little.)

To state that this is wrong, and that there is some connection between what we had previously supposed to be disjoint, there has to be some clue, some incident, that forms a hitherto-unknown link between the two.
That link will then be investigated. Sometimes the new link will lead to a fruitful new field of endeavor, and sometimes it won't. If it doesn't, there is no good to come of proclaiming that there are boogeymen in the shadows (again, so to speak).

The "good enough" attitude is not really a statement that no effort is being put into furthering the state of the art .. if it were, we would have no -120 dB DAC performance levels. Someone has to be pushing the boundaries of present-day performance to get those figures. I think we can be assured that there is effort in side-effects, also. Issues of RFI/EMI have been found to exist, and have been addressed in electronic designs. There have been investigations into acoustic phenomena on the human body by the military, and if I know the military , any least little effect noticed would be followed up with massive investigations.

There's nothing like military paranoia to fuel scientific investigations.

So progress is being made. Some pathways yield results, and some do not. But as long as you can see some new gear on the market, some new applications, some new software, you can be assured that people are tirelessly at work behind the scenes to chase better performance ... and awareness.

(The military isn't the only factor in pushing SOTA boundaries; a competitive market fuels scientific investigations, too. )

As for any of those entities giving you "the whole story" ... the "whole story" must first exist other than in our minds. Science does not address some anomalous dread. It addresses, step by step, the clues that lead to new knowledge. If there are clues, then there is investigation. If there are no clues, then there is generally no investigation.

If you have clues, they need to be presented, and then there will be efforts taken. After all, you said ...

And it's not just a me-oppinion, there are hundreds/thousands of related studies.

Please provide links to those studies. Lacking that, efforts are, as I said in the beginning of this post, just jousting at windmills.

Jim

 

[solderdude]

However, I am not on board with the "good enough" attitude. I want more, I want better, I want to see scientists/manufacturers/etc with an yes-we-can attitude. People who do not only investigate/fix issues that we are aware of, but also some that we are not (and hopefully do not charge an arm and a leg for it.)

Those improvements would have to occur in the transducers, not the electronics. The bottleneck does not have to be the electronics but choose the wrong gear and one can easily reach limits.

You must have set 'limits' for yourself what electronics have to comply to. What do you believe are minimum requirements ?
Can you disclose what properties you want improved upon and why ?
What issues are 'we' not aware of and if that is the case how can we become aware (why isn't it enclosed in a wave-form) ?

 

[lashto]

I believe that this stage of the game is simply jousting at windmills, so to speak.

That would be a good definition for science . And one of the aspects I like most

Please provide links to those studies. Lacking that, efforts are, as I said in the beginning of this post, just jousting at windmills.

did that in several messages above. But I can understand that everyone wants the proverbial 3-words-summary .. and summarizing the links would be helpful for me too (was thinking about a new thread).

... list ongoing ...
Vibroacoustic Therapy (VAT): new field of medical science (infrasound). Hundreds of studies, probably best to follow the wiki links and/or google (instead of using whatever links I may pick.)
Whole Body Vibration (WBV): same as above, even lower freqs.
A Review on Biological Effects of Ultrasounds: meta-study/analysis, cites and biblio-links ~150 studies (some more and some less applicable to hifi/audio.)
Effects of Ultrasonic Noise on the Human Body: same as above, ~50 linked studies.
Audibility limits are not exactly 20-20:

• infrasound Hearing at Low and Infrasonic Frequencies. Below 10Hz at (reasonable) 100dB levels.
• ultrasound Hearing thresholds for pure tones above 16kHz. Up to 28 kHz at (reasonable) 100dB levels.
• The range seems to get larger with every new study/measurement. Better studies? Better equipment? Could it be that our ears/brains are evolving?!...

 

[lashto]

Those improvements would have to occur in the transducers, not the electronics. The bottleneck does not have to be the electronics but choose the wrong gear and one can easily reach limits.

You must have set 'limits' for yourself what electronics have to comply to. What do you believe are minimum requirements ?
Can you disclose what properties you want improved upon and why ?
What issues are 'we' not aware of and if that is the case how can we become aware (why isn't it enclosed in a wave-form) ?

setting goals and limits is of course very helpful. Never thought about making a clear list, was too busy "jousting" . Mainly cause I got annoyed by all sorts of "dacs/amps are perfect" and "audio is done" posts. There was even a recent thread like "audio was done last century". Yeah sure!

And yes, transducers look like the biggest, most obvious fish...