Psychoacoustics Fundamentals

[RayDunzl]

Is the M2 speakers or monitor?

Master Reference Monitor

https://jblpro.com/en/products/m2

 

[j_j]

​

Ballou (1) identifies that for convenience the audible spectrum can be divided into four regions:

• Region X: a very low frequency region, wherein no modal effects can occur;
• Region A: a low frequency region dominated by normal modes;
• Region B: an intermediate frequency region dominated by diffraction and diffusion;
• Region C: a higher frequency region dominated by specular reflection.

The frequencies bounding these regions can be calculated for a given room if the room dimensions and reverbera

To me, this is confounding two different issues, the first being "acoustics of rooms" and the second being "what can the ear/ears detect".

Whew. I'm in the middle of writing a 1 hour talk on some of this for the PNW AES. Maybe later. I'm going to talk about what parts you can hear in that forum, to some extent, and how that interacts with the soundfield around your head, again, to some extent. 1 hour is just a start, of course.

 

[Bentoronto]

I guess the question is: do we have a mechanism in hearing analogous to size-distance constancy in vision? Does a string quartet recording played softly at night sound false (due to bass sounding relatively low, as per F-M chart) compared to a string quartet (recorded or live) 100 feet away?

BTW, only the bottom trace in the equal-loudness chart relates to sensitivity/threshold. The other curves are how people answer when asked for equal loudness judgments.

B.

 

[j_j]

I guess the question is: do we have a mechanism in hearing analogous to size-distance constancy in vision? Does a string quartet recording played softly at night sound false (due to bass sounding relatively low, as per F-M chart) compared to a string quartet (recorded or live) 100 feet away?

BTW, only the bottom trace in the equal-loudness chart relates to sensitivity/threshold. The other curves are how people answer when asked for equal loudness judgments.

B.

They are still equal loudness curves, just the absolute threshold is "zero loudness". You can't go below zero.

Hearing is very different than vision. This might help a bit:

http://www.aes-media.org/sections/pnw/ppt/jj/audiovsvideo.ppt The answer to your question lies in understanding how the differences play out. I don't have a deck on that directly, sorry.

 

[Bentoronto]

..Hearing is very different than vision. This might help a bit:

http://www.aes-media.org/sections/pnw/ppt/jj/audiovsvideo.ppt The answer to your question lies in understanding how the differences play out

Now if I replied, "Pity so few engineers-types take Psych 101. If they did, they might have some grasp of perception. Try not to publicize that PPT", you'd prolly expect me to give examples. So I better not make that my reply.

Now here is some little known research into the Doppler Illusion (no, not really about train whistles or red dwarf stars or large full-range cone drivers). I bet everybody reading this forum will say, "I had no idea human perception worked that way. I couldn't imagine that to be true before."

https://www.researchgate.net/public...f_Dynamic_Intensity_Change_on_Perceived_Pitch

B.

 

[j_j]

Now if I replied, "Pity so few engineers-types take Psych 101. If they did, they might have some grasp of perception. Try not to publicize that PPT", you'd prolly expect me to give examples. So I better not make that my reply.

B.

Really, now? Perhaps you should speak a bit more clearly. In particular, you asked about distance mechanisms, so you've conceded a very important point there. Your question asks something very well known in the field, for which there have been a variety of (mostly misguided) attempts to correct.

Loudness, especially if it's proportional restoration, is quite a feat. You might find a few patents on the subject.

 

[Bentoronto]

Really, now? Perhaps you should speak a bit more clearly. In particular, you asked about distance mechanisms, so you've conceded a very important point there.

Sure. Can a one-eyed person play basketball?

There are a whole bunch of cues to depth (not "hints") of which stereopsis - LOVED LOVED LOVED by engineers - is just ONE of them. Moreover, if you wear special glasses to change one eye so screw up stereopsis, you hardly notice any change in anything. Also, several of the depth cues will readily over-ride stereopsis. So that's why somebody might doubt the information in the PPT. (OK, maybe stuff not covered in Psych 101, but you get the idea, I am sure.)

B.

 

[j_j]

Now here is some little known research into the Doppler Illusion (no, not really about train whistles or red dwarf stars or large full-range cone drivers). I bet everybody reading this forum will say, "I had no idea human perception worked that way. I couldn't imagine that to be true before."

https://www.researchgate.net/public...f_Dynamic_Intensity_Change_on_Perceived_Pitch

B.

Yeah? Well known, actually. Pitch shift as a function of level is all that's pointing to, or so it looks to me, and that's very, very old news. Now, tell me why it shifts one way at the window end of the basilar membrane, and the other way at the other end by the heliocotrema. Got Beef?

You are aware of Jont Allen's work on basilar membrane tuning, excess upward spread of masking, and the like, right? Following Zwislocki, right? Hello? Yes? No? you think shift of the resonance point on the basilar membrane as a function of level (shift vs. the tectoral membrane, changing the phase of the inner hair cell firings) is new? You are familiar with excess upward spread of masking, right? Yes? Do you see the connection yet?

WELL? DO YOU?

---Added later after finding more on the paper Ben B cited---
Actually, this also may be related to the point early in my slide deck where it shows that the higher-order part of the CNS can guide the actual analysis of auditory objects. It's a bit hard to tell without having the full paper on hand, and knowing better what the stimulus is.
---end of added text

As to your unwarranted professional disparagement about stereopsis, I said right in the slide deck:

"
•Cover one eye and you still have “hints” about how far away things are
•Plug one ear and you still have “hints” about how far away things are
"

I will add that distance perception is much less accurate for a variety of reasons in hearing. Normally I might discuss that, but I don't really teach people who engage in your kind of conduct.

That rather demolishes your straw man claim that I only mention stereopsis. You didn't even read the work you wantonly disaparaged.

Now I do make a distinction between things that are directly captured by the periphery and things that can be derived from the capture. There's a reason for this, can you tell me why I would point that out?

As to the question of timbre changes due to intensity, well, loudness corrections have been attempted. I know of at least one that worked quite well, and many (fixed corrections will never work well on a signal varying in intensity) that mostly act as a bass boost. (That being something people seem to like but now we're talking preference, not distance measures.)

I suggest, politely this time, that you fully retract your disparagement without qualification.

 

[amirm]

BTW, only the bottom trace in the equal-loudness chart relates to sensitivity/threshold. The other curves are how people answer when asked for equal loudness judgments.

B.

JJ is one of our technical luminaries and superb expert in this field. I suggest not giving him pedantic explanations like above which you can read in the Wiki. It only comes across as insult when you try to give lessons to your teacher.

 

[AudioStudies]

It did kind of seem like Barney Fife versus Einstein . . .

 

[Wes]

I guess the question is: do we have a mechanism in hearing analogous to size-distance constancy in vision? Does a string quartet recording played softly at night sound false (due to bass sounding relatively low, as per F-M chart) compared to a string quartet (recorded or live) 100 feet away?


.

yes, if the source is a known one; dunno re string quartet

 

[j_j]

yes, if the source is a known one; dunno re string quartet

Even then, the background noise and the acoustic environment also enter into consideration. The kinds of dispersion one gets in an open field is often a surprise to those who haven't measured it. I can't say a lot about that presently, though, sorry.

 

[Bentoronto]

Yeah? Well known, actually. Pitch shift as a function of level is all that's pointing to, or so it looks to me, and that's very, very old news....

All true. In fact, it has been known for, I'd guess, centuries that singers have a different pitch depending on how close they hold the tuning fork. Some may even know in which direction of frequency without googling it.

But let's go back to the Doppler Illusion. The experiments showed that belief in the Doppler effect (yes, the train whistle stuff) distorts your perception of pitch. Anybody knew that before?

Funny thing, many people believe that the sound of an oncoming train is rising in pitch as it approaches. No need to raise hands, we know who you are: that is false.* Bur since the participants believed it, they heard it. Not of great importance to know, but I linked it because it is strange and because it can be considered an example of inter-modal perception influence.

Based just on the PPT comparing vision and hearing, I formed the impression that the author does not have a good grasp of visual perception of depth. I'll stick with that. But it may be that the author of the PPT knows a lot about hearing perception as it applies to audio engineering and I am sincere in apologizing if my criticism was carelessly general to that realm.

B.
*Doppler shifting only happens when velocity is changing, not when the train or star is coming at you at a constant rate

 

[Emlin]

All true. In fact, it has been known for, I'd guess, centuries that singers have a different pitch depending on how close they hold the tuning fork. Some may even know in which direction of frequency without googling it.

But let's go back to the Doppler Illusion. The experiments showed that belief in the Doppler effect (yes, the train whistle stuff) distorts your perception of pitch. Anybody knew that before?

Funny thing, many people believe that the sound of an oncoming train is rising in pitch as it approaches. No need to raise hands, we know who you are: that is false.* Bur since the participants believed it, they heard it. Not of great importance to know, but I linked it because it is strange and because it can be considered an example of inter-modal perception influence.

Based just on the PPT comparing vision and hearing, I formed the impression that the author does not have a good grasp of visual perception of depth. I'll stick with that. But it may be that the author of the PPT knows a lot about hearing perception as it applies to audio engineering and I am sincere in apologizing if my criticism was carelessly general to that realm.

B.
*Doppler shifting only happens when velocity is changing, not when the train or star is coming at you at a constant rate

Bollocks.

 

[j_j]

But let's go back to the Doppler Illusion. The experiments showed that belief in the Doppler effect (yes, the train whistle stuff) distorts your perception of pitch. Anybody knew that before?

Well, I'm sure it's not the whole story, but why don't you look at the number of times I've pointed out expectation bias to people, including here.

Based just on the PPT comparing vision and hearing, I formed the impression that the author does not have a good grasp of visual perception of depth. I'll stick with that. But it may be that the author of the PPT knows a lot about hearing perception as it applies to audio engineering and I am sincere in apologizing if my criticism was carelessly general to that realm.

The talk was developed to give to audio people, and the KISS principle applied to vision. Know your audience.

If you bother to search for video patents, you may dismiss your concerns in vision as well, thank you.

 

[SIY]

Doppler shifting only happens when velocity is changing, not when the train or star is coming at you at a constant rate

If memory serves, the Doppler shift was linear in source velocity (or the reciprocal of the source velocity) in the inertial frame of the listener.

 

[JustAnandaDourEyedDude]

B.
*Doppler shifting only happens when velocity is changing, not when the train or star is coming at you at a constant rate

Try telling that to a traffic court judge next time you fight a speeding violation traffic ticket. Or try telling a plenary meeting of the Royal Astronomical Society that the measured expansion rate of the universe is based on a psychological illusion.

 

[BDWoody]

But it may be that the author of the PPT knows a lot about hearing perception as it applies to audio engineering and I am sincere in apologizing if my criticism was carelessly general to that realm.

Yes, he may indeed.

https://www.audiosciencereview.com/...sing-and-psychoacoustics-master-library.2066/

 

[j_j]

B.
*Doppler shifting only happens when velocity is changing, not when the train or star is coming at you at a constant rate

If something is coming at you at a constant velocity, the amount of shift remains constant. The reason for the drop in pitch as something passes you is that the relative velocity changes rapidly as the source changes velocity rapidly, BUT the sound goes from above the emitted pitch to below the emitted pitch as it passes you. The pitch shifts as it passes you, but has been shifted both before and after by a constant amount until the point where the relative velocity begins to change appreciably.

 

[RayDunzl]

I wish I could type and wave my arms around at the same time.

Do you guys use Speech to Text to get around my limitation?


How about a magic trick?