What covid research can teach us about audio measurements.

erik,

But that is a pretty vague claim.

If for instance someone is measuring a cable, or an AC cable, or a USB cable, and

finding "there is no difference in the signal"...and someone wants to say "Actually, you are missing something" it behooves that person to actually explain what they are missing.  And if possible suggest how to measure instead.

But if it's all vague hand waving, like "maybe there is something people are hearing that you aren't measuring for"...then what does that give anyone to work with?

How does that help discern nonsense claims from plausible claims?

@prof

There was a post here a while ago from a psychologist/researcher who aptly collected what I keep trying to say.

A measurement of THD is a measurement of THD. A measurement of frequency response is a measurement of frequency response. To extend those measurements beyond that is not science, it is pseudo science. To take those measurements and discuss "ideal" or the end of all things that can be heard is not science. It is also not science to repeat measurements and rank equipment based on them. That is quality assurance.

It is also not science to lump average human perceptions and claim this is how 1 individual hears.

There is no scientifically agreed to set of measurements which together describe all the human ear/brain is capable of hearing. All we have is a minor number of measurements which are in popular (well, as popular as audio is) culture.  I doubt those measurements which Stereophile publishes, are even close to all that is used in modern engineering and development.

As for the rest, caveat emptor, but I won’t hide under the umbrella of science when I’m actually ignorant.

Best,

 

Erik

@ebm

 

Single line replies are sad.

 

Our brains do a lot of correction, making sound into what we expect to hear, given our experiences.  Some day we'll see how hard it works via brain scan.  That could be a key measurement in ear fatigue vs relaxation.  

My analogy is another sense - Vision.  I wear a not unsubstantial prescription that includes near sightedness and astigmatism.  With a new prescription or a change in lens material or even just a regrind, first tryout is always disorientation.  Peripheral vision is warped with straight lines noticeably curved.  After a few days everything appears normal again.  That's my brain at work "getting used to it".  Tests say I'm 20/20 corrected (or so).  That's the measurement standard all prescriptions are judged by.  No test measures how hard my brain works to "get used to it" or why everything looks more natural, atmospheric and relaxing when I take off my glasses.  

Like others have said, I do not see the relevance at least to the arguments in audio. Few if any of the scientific community doubt the existence of long Covid, and physiological and psychological testing confirms it exists. Knowing it exists, they went looking for the cause. You will have to provide strong proof of something in audio that contradicts current scientific understanding in order to get them to chase the cause. I am sure we could come up with 5 or 10 things, medical related, that many people are convinced are true, that the medical community is not chasing, or has chased and debunked. Are not most measurements in audio a simple electrical signal, no matter the source?  How much more complicated does it have to get than X = A-B. A = input, B = output. Hardly as complicated as the human body. The other measurements in audio are speakers, and microphones. No one considers those settled science. If they did I would be out of a job. Fortunately I will retire before we have direct brain plug in.

A measurement of THD is a measurement of THD. A measurement of frequency response is a measurement of frequency response. To extend those measurements beyond that is not science, it is pseudo science.

 

I doubt I will make any impact in this discussion as a discussion of measurement takes a level of understanding of several topics that is likely beyond most people participating in this discussion.

Stereophile presents a limited set of measurements.

Audio Science Review presents a more comprehensive set of measurements but are limited in time.

Do engineers and manufacturers do more tests? Some do. Many do not. Many of the tests may not be for sound. For speakers, I expect many small brands don't have the equipment or knowledge for extensive testing, certainly not for speakers.

I wrote a long paragraph but deleted it. I would suggest reading this and coming back:  https://www.ap.com/technical-library/using-multitones-in-audio-test/  I don't think this existed 20 years ago or even 15.  "The characteristics of a multitone waveform (e.g., spectral content, histogram, crest factor, etc.) give it a much closer resemblance to typical audio program material like music or speech, than a single sine wave"

 

The speaker testing we do is much more comprehensive. Electronics are nice, predictable, and repeatable (maybe not that SET amp). Distortion normally scales with level, frequency response does not change with levels (it may with load). Nice. Easy. Speakers are nasty beasts. Distortion can be low then rise rapid, and is different at every frequency. Impedance can change with level, which can lead to changes in frequency response (and crossover). Different drivers have different dispersion. Distortion is not consistent across angle. Voice coils heat up leading to parameter changes and passive crossover shifts.

I would spend far less time worried about whether your electronics are tested adequately and spend a lot more time worrying about whether your speakers are tested properly.

 

 

@thespeakerdude

Few if any of the scientific community doubt the existence of long Covid, and physiological and psychological testing confirms it exists.

 

The symptoms of ’long flu’ were well established before it became rebranded into a money making exercise of the most unprecedented levels.

 

What can the audio industry learn from this?

How about starting by creating doubt and fear in the minds of the potential customers? Admittedly the numbers of audiophiles is somewhat smaller than the planets current human population, but that’s just something else to work on as Pfizer have recently demonstrated by seeing off most of their market rivals.

 

Well, there’s already ’journalists’ already working flat out to create more fear and doubt in the minds of ardent audiophiles. Some of them regularly champion esoteric cables, overkill power supplies, cryogenics, MQA, 180 gram vinyl, cable lifters etc.

 

Whether the audio industry could go further and try to force all the public to upgrade their systems by mandates is rather unlikely at this point.

Upgrade passports are also somewhat difficult to forsee.

Besides, how many upgrades would you need to be allowed free travel?

One, two, three, four or more?

 

I believe that even Joe Biden’s speech writers might struggle to concoct any kind of plausible speech for their resident puppet in chief. Undoubtedly some kind of reference to climate change and the war in Ukraine would be involved.

’Your upgrade helps reduce carbon emissions and to fund our, err I mean Ukraine’s troops’ etc etc

Could the entire global media be marshalled into a concerted publicity drive to stress the need to upgrade is also hard to imagine.

Would the Disney owned Marvel Comics go as far as depicting the likes of Spider-Man and Captain America queueing up for high end auditions?

 

Perhaps what the industry really needs is the likes of Klaus Schwab and the WEF to get behind them.

I don’t think EISA - pause for laughter Expert Imaging and Sound Association - has the same kind of clout that Klaus’s World Economic Forum currently has.

 

Yes, they could bring in the Great Hi-Fi Reset by the year 2030.

You will own Hi-Fi and You will be happy.

 

Hmm, sounds noticeably better than their alleged current plan...