Volume Matching JND

[John Kenny]

Okay, you have Don's input on the matter. I have done my own tests that might not make it to .2 db, they do make it to .25 db.

There is this:
https://archive.org/stream/pdfy-ZGJ4B3_VGwVs9CCt/Can-You-Trust-Your-Ears_djvu.txt

One of the items is a test with 31 people half of two 30 second bits of music are level matched, and half aren't. The unmatched ones are 1 db louder. No one picked up on a loudness difference with music. 75% described a quality difference.

As I read further into this article it began to light up more more warning lights due to it's unscientific & incorrect statements, then I came across this "In the experiment de-scribed above, the subjects said that they "preferred" one of two identical sound clips more than 75 percent of the time, even when there was a "No Preference" box to check on the score sheet." Hmmmm, if you want to present evidence for a preference & don't believe in anecdotal reports, then don't present an anecdotal report.

So is it .1 db or is it 1 db? It is somewhere in that range. Since there are now a few instances relayed to you how people hear a difference, ascribe it to quality and don't perceive the difference is loudness the case is on solid ground that at some point below where listeners hear a loudness difference they do hear a quality difference. Maybe you don't have certainty it is just above .1 db, but it is at or below 1 db. It indicates matching by ear to perceived volume equality leaves a gap of some size where you still hear quality differences even if none are there. So that should make one wary of level matching by ear. As you at that point have to do some kind of measuring even if only with a multi-meter you might as well do it to .1 db. If someone only does it to a .25 db it might be worth looking into. I wouldn't give much credibility to more than that myself as some tests of JND with complex signals show a threshold of only .5 db. So that question is pretty well answered for you.

The JND for music is not quite as firmly established. The general trend in audio testing is listening tests with appropriate artificial signals is more discerning than with music. If you are striving for much rigor you wouldn't use the loosest criteria. So if the JND for music is 3 db, I wouldn't accept listening tests about much using matching no better.

OK, thanks

 

[Blumlein 88]

As I read further into this article it began to light up more more warning lights due to it's unscientific & incorrect statements, then I came across this "In the experiment de-scribed above, the subjects said that they "preferred" one of two identical sound clips more than 75 percent of the time, even when there was a "No Preference" box to check on the score sheet." Hmmmm, if you want to present evidence for a preference & don't believe in anecdotal reports, then don't present an anecdotal report.

OK, thanks

OK I am done with you JK. As usual your posts are not in good faith. You are not here to learn share educate or explore audio science.

I also am done with the forum. If Amir learns how to clean it up. I might come back one day.

As my greatest contribution to the forum seems to have been my avatar, anyone who wishes can use it for themselves.

 

[John Kenny]

OK I am done with you JK. As usual your posts are not in good faith. You are not here to learn share educate or explore audio science.

I also am done with the forum. If Amir learns how to clean it up. I might come back one day.

As my greatest contribution to the forum seems to have been my avatar, anyone who wishes can use it for themselves.

Actually, I apologise, I miss-read the text - I read it as "even though there were no preference box to check on the score sheet"
It's too late here for reading & posting - I should not stay up so late.
I did find his analogies prior to that text were not convincing though - jumping in the water & it's cold - getting out of the water & it's cold - there are good scientific reasons for that - also his story about putting two swatches of paint side by side as an analogy for A/B testing is unconvincing & way off what's being done in an auditory A/B test - audio is a signal over time (paint swatches are not) - finding the audio clip to compare to use the visual analogy is like trying to find a frame in a video which has a difference in a colour to the same frame in an alternate version of the video

 

[AJ Soundfield]

I was hoping to get you to discuss science or audio

"SAM", still waiting for you to explain how these audio tests support audiophile beliefs, rather than debunk them.
They will never understand, but I will.

 

[amirm]

OK I am done with you JK. As usual your posts are not in good faith. You are not here to learn share educate or explore audio science.

I also am done with the forum. If Amir learns how to clean it up. I might come back one day.

As my greatest contribution to the forum seems to have been my avatar, anyone who wishes can use it for themselves.

I guess I am at a loss as to why you are taking it out on the forum because of what JK is saying. The place I created where we can have fun and talk about audio technology remains. Why not just post in the music section? Or just read the technical posts? We love to continue to have you here. The nice avatar of yours puts a smile on my face every time I see it as do your posts. Just ignore the people who raise your blood pressure. Engaging those folks just adds to what bothers you. Interact with Thomas, Bob, me, etc. and you shouldn't have issues.

 

[Bill Bainbridge]

@John Kenny: In a somewhat well-documented (and scientifically studied) response to your topic query as posted links from blumlein88 and others imply: It depends. The exact nature of the signals obviously has great influence on the perception of differences- frequency range, SPL or other audio power metrics, harmonic content, envelope (a huge influence that has only been rigorously studied recently). If the object of your original question was to make a level-setting precision range that would be less likely to interfere with test results, I would suggest as small a difference as possible, why not 0.1 dB?
That the scientifically-derived goalposts (regarding JND and other metrics) have changed over the years is actually not surprising, as each study has had to quantify as small an observation as can be experimentally verified within a range of variables that are themselves vast, relatively invisible, and difficult to isolate. Our real (internal) experience of audio is in no way diminished by the real (external) measurement of physical properties of the stimuli that initiate those experiences. Indeed, as the practical results of those measurements we can enjoy the increased enhancement that technological devices offer to our collective and personal internal experiences.
If you agree with the statement above about the variability of JND, then there should <never> be an end to the scientific inquiry regarding it and its dependent variables, therefore: IT DEPENDS.

@blumlein88: Please do not retract your participation due to perceived antipathy from any member here, as such withdrawal would diminish the validity of the many extremely valuable posts and research you have graced this forum with to date. Yes, it can seem to be a severe psychological struggle sometimes to persevere with data presentation against the opinions those whose truths are already catalyzed, but if you agree (as I, and I believe you do) that there should never be an end to scientific inquiry, then perceived contention is in fact a necessary coefficient in this process. Repeated assertion validation is a key component of The Scientific Method!
Regarding the last paper you linked to, which caused JK to react with incredulity, I can see that it was an early, casually established article, with many variables/resources left unmentioned. I wouldn't go so far as to say it was entirely anecdotal, unscientific, or incorrect- those findings are unwarranted for an article intended for lay readership such as this, but it does interest me enough to look for validation sources for some of its bolder assertions, and further to view its findings as possibly premature given some of the latest studies and papers you had linked to earlier.

 

[amirm]

Very good post Bill. Welcome to the forum. I had to ban John Kenny a while back due to poor personal conduct and Blumlein88 is back and active.

Hope to see more of you.

P.S. Do you live in Bainbridge Island? If so, you are just an hour so from where we live.

 

[Bill Bainbridge]

Very good post Bill. Welcome to the forum. I had to ban John Kenny a while back due to poor personal conduct and Blumlein88 is back and active.

Hope to see more of you.

P.S. Do you live in Bainbridge Island? If so, you are just an hour so from where we live.

Thanks for the welcome, Amir. Sorry about Kenny, glad for Blumlein88's return. I actually live in south Seattle, and yes, I'm distantly related to the island's namesake

 

[amirm]

Ah cool.

The story of JKenny is that of the scorpion that bites the friend or foe. It is its nature as they say. Kept him here as long as I could but then there were no option.

Welcome again. We are still one hour apart from where you live.

 

[fas42]

Hi Bill - if you look around here you will see that I've been active on posting about this type of thing - and am especially interested in recent research on such matters. You mentioned

The exact nature of the signals obviously has great influence on the perception of differences- frequency range, SPL or other audio power metrics, harmonic content, envelope (a huge influence that has only been rigorously studied recently)

Would you possibly have any links to this material?

Thanks!

 

[Bill Bainbridge]

Frank, I'll have to see if I can dig up what sources I have, but as you so brilliantly pointed out ASA has a tremendous amount to offer for this exploration! Thanks again!

 

[Bill Bainbridge]

Just a quick post to point out an online primer on psychoacoustics with relevant data regarding JND of loudness being approximately 1 dB, under conditions of mid-range frequency, mid-level SPL, and "normal" noise shape:
http://acousticslab.org/psychoacoustics/PMFiles/Module04.htm
Relevant to this thread- If JND for Loudness is measured at 1 dB for these "normal" conditions, wouldn't it be prudent to calibrate our systems (whenever possible) to 0.1 dB? After all, for critical conditions in other areas of engineering a 10:1 design factor ("safety factor") is not uncommon.

See the text approx. "Effects of Duration on Loudness" and onward. Time-based effects (envelope) may have an effect on perception of Loudness (and by implication) many other perception metrics: Pitch, overall Frequency Response/ Timbre, and possibly others. This shouldn't actually be too surprising, given that the initial stimuli to these responses have two primary variables: Energy and Time.

At risk of redundancy, I'll C.C. this post to the ASA thread as well, as it relates to perception in general.

 

[fas42]

A point I would make, perhaps again, is that JND expressed as a decibel variation is meaningless in the types of distortion artifacts that I find critical in listening variations. An analogy would be having a car which is running smoothly; then one day a clicking noise, which occurs somewhat randomly, starts happening. Varying the dB level of the clicking is of no value, because you're now aware it's something that shouldn't be there, and your hearing picks it up, every time. Only the complete absence of the clicking will now satisfy you - this is a black and white situation.

 

[DonH56]

What if the clicking were only heard at idle, or at certain speeds? Alas, I find little in life or audio is back and white...

 

[fas42]

Don, that one hears it in any particular situation while using the car, when it was absent prior to first hearing it, is the black and white of the situation. Yes, sorting it out may be very un-black and white, and may be very difficult to properly achieve - but I'm referring to the subjective perception of there being a problem, which you're not happy with.

 

[RayDunzl]

I had a sound like a speedometer/odometer cable scraping it's sheath, that would only be noticed after driving at speed (interstate) then heard on the off ramp while slowing, and wouldn't stop until below 10mph or so.

Once it stopped, speeding up above 10mph didn't restart it, but another fast ride would.

Drove 300 miles fast recently now it seems to be gone (not done that for a long time).

Looking at the parts diagrams for the car, I couldn't find a cable like that, so, I have no idea what it was. The speedometer/odometer seem to be electrically operated, though they look old-style.

Hey, you guys dragged cars into it.

 

[fas42]

Well ... ... actually, our car has developed that speedo issue somewhat recently - but only when first starting the journey, disappears fairly quickly ... but hey, it's had a good life - it's excused !!

 

[Blumlein 88]

I had a sound like a speedometer/odometer cable scraping it's sheath, that would only be noticed after driving at speed (interstate) then heard on the off ramp while slowing, and wouldn't stop until below 10mph or so.

Once it stopped, speeding up above 10mph didn't restart it, but another fast ride would.

Drove 300 miles fast recently now it seems to be gone (not done that for a long time).

Looking at the parts diagrams for the car, I couldn't find a cable like that, so, I have no idea what it was. The speedometer/odometer seem to be electrically operated, though they look old-style.

Hey, you guys dragged cars into it.

Brake pad nearly worn out perhaps. At speed it heats up a bit and scrapes slightly. Slow down, let it cool, it doesn't touch anything again until another bout of high speed drivings heats it up.

You could record the sound if it is loud enough using a smartphone. You might find the sound matches tire RPM or something.

 

[Bill Bainbridge]

Frank, the point I'm making about loudness JND actually is (I think) in support of your cause. There are it seems many inter-dependencies of variables in listening and perception that are recently being proven to exist. These discoveries will take quite a while to have an impact on the technologies of reproduction and the science of measurement of those qualities. Until we have a more informed metric, the prudent thing to do for those measurements that currently need to be made is to use as much precision as possible, in order to reduce the possibility of false negatives as a result of observational oversight.
Without doubt (at least in my consciousness) our collective "ear-brains" will remain the most powerful tools to shape the technologies of audio for quite some time.

The statements above do not negate the "perceptual lensing" that you now experience with the clicking sound in your car; it's possible however that the clicking was already there and the "trigger point" hadn't been reached for you to perceive it. There's no way to tell whether that change was due to internal or external variables unless you pop the hood.