Subjective sound bokeh - interesting analogy.

[Neuro]

Image bokeh is related to how the blur in the background of an image contributes to the overall perception of the image.
I get bad image bokeh from old 500/8 mirror telephoto lenses with round rings in blurry parts. Good bokeh is provided by my Canon 55/1.2 and 85/1.8.
The image is sharp in a significant part of the subject where blurry parts subjectively emphasize the overall image perception.

Sound bokeh is a subjective perception of the overall sound in a certain context.
Direct sound can to some extent be compared with the sharp focus area in the image. Perception of direct sound gets an additional dimension through reflections. Direct sound alone without reflections usually does not produce good sound.
Sound bokeh in different rooms varies with the mix of direct sound/reflections.
Bad sound bokeh is obtained in a long, narrow cave where the reflections are more than 12 dB stronger than the direct sound. Any speech is completely masked by the reflections and cannot be understood.
In ordinary listening rooms, the sound bokeh is usually half-good. The reflections do not highlight the direct sound optimally.
Optimal perceived sound bokeh is subjective and is often an adaptation process with elements of compromise. The adaptation process often wears off and the search for better sound bokeh often affects the hi-fi nerd.

Optimal sound bokeh is very dependent on the properties of the sound source and the room as well as your own subjective preferences.

Personally, I have had different optimal sound bokehs over the years.
Initially, my first stereo was a huge improvement, an enormous bokeh, compared to the family transistor radio.
Then came further bokeh improvements with horn speakers and the possibility of high sound volumes. Sound above 85 dB masks measurable distortion and gives subjectively lower distortion.
The tube amplifiers gave further sound bokeh lift with a softer sound. Masked 2nd/3rd distortion.
EQ gave even better sound bokeh with better bass below 300 Hz in the listningpositionen and linear frequency curve measured above 300 Hz in open field.
Dipoles gave further new bokeh improvements in the spatial experience through more optimal reflections.
Newly built big house with more optimal reflections where the lateral reflections were dominant (attenuated about 8 dB, delayed about 17 ms and similar frequency curve as the direct sound. Other reflections should be about 30 dB attenuated.(Barron, Toole, Olive, Lokki)
The characteristics of the reproduced sound are also crucial. Speech and dense music often give different good sound bokeh in a given system and room.

Objective measurement data often but not always correlate with good sound bokeh.
With the right choice of measured data, physics can improve perceived sound bokeh.

Be careful and proud of your own subjective sound bokeh in a given room.

Neuro

 

[dlaloum]

Nice analogy!

 

[Neuro]

Toole/Olives spinorama provides partially relevant but not sufficient information for optimal sound bokeh.
The subjective perception in the listening position of a speaker's direct sound, dispersion patterns, the reflections in the room require more focus on more relevant measurable data.
As a senior neuroscientist with focus on brain tumors, brain anatomy and functional brain imaging, I find it strange that so little is done by colleagues with respect to how physics affects neurophysiology and neuropsychology. After reading Toole's last three editions of Sound Reproduction and downloading thousands of relevant studies I have concluded that there are many relevant areas which are suboptimally investigated and not described.
At present I have the basis for a number of review articles and very interesting studies. I lack a sounding board with some physical experience and preferably some knowledge in neurophysiology/neuropsychology. My research is published through The Karoliska Institut Sweden. Any suggestions?

Neuro

 

[Juhazi]

I would be careful with presenting new terminology from photography/video to sound perception https://en.wikipedia.org/wiki/Bokeh
My first association with bokeh is the ratio of direct and reflected/late arrival/modes which was introduced by Schröder https://en.wikipedia.org/wiki/Room_acoustics
Noise and ambient irrelevant signals are always present in real life, but brains have enormous ability to filter them. Individual variations are obviously large.

Sound is always dynamic and time-variant phenomenom and it's perception is a specific branch in psychoacoustics and neurophysiology. Sound perception of humans in naturals spaces, large halls and small rooms and reproduction by loudspeakers or headpones has been widely studied and IMO basics are well known by experts. Like any science or medicine, understanding is constantly evolving, sometimes with great steps.

Dr. Griesinger is considered as an expert in psychoacoustics Scroll down on his mainpage to see articles http://www.davidgriesinger.com/
Extensive studies are done in many universities around the world

Neurophysiology is now mostly interested in hearing aids, obviously fundamentals are known well enough https://www.mdpi.com/2079-7737/14/9/1309

Psychology - emotions and affections to different music or auditory experiences is an interesting area. Individual, common, culture, age, era variations...

Music and emotion - Wikipedia

en.wikipedia.org

---
ps. I am just a retired dentist with interest in sound reproduction and psychoacoustics

 

[Keith_W]

ps. I am just a retired dentist with interest in sound reproduction and psychoacoustics

Those sound like interesting subjects to get your teeth into! I need to brush up on my knowledge a bit. The last time I may have bitten off more than I could chew.

Anyway, I think "sound bokeh" is an interesting analogy. I like it - a sharp image (the subject) stands out against the blurred background. The more blurred and muted the background, the more emphasis on the subject.

 

[dualazmak]

Hello OP @Neuro,

Since I really enjoy not only amateur-audio-DIY-based music listening but also photographing using nice DSLR camera plus excellent lenses, your analogy of "sound bokeh" is very much interesting (and sound rather familiar) for me; ("bokeh" in photography is intentional and/or non-intentional out-of-focus/blurry in whole and/or specific portion of image.)

Optimal perceived sound bokeh is subjective and is often an adaptation process with elements of compromise. The adaptation process often wears off and the search for better sound bokeh often affects the hi-fi nerd.

Optimal sound bokeh is very dependent on the properties of the sound source and the room as well as your own subjective preferences.
....
....
Be careful and proud of your own subjective sound bokeh in a given room.

Yes...
After reading your initial post, now I feel that my recent inquiry regarding "3D sound perspectives" (ref. here #124) given by my present/latest audio setup in my own listening /acoustic environments would be somewhat, more or less, dependent on your mentioned "sound bokeh" of my present sound perspectives, I assume.

BTW, in July last year, I posted one typical photo with beautiful (and rather intensive) "bokeh" background taken by CANON EF24-105mm F4L IS II USM lens attached to CANON EOS 5D Mark IV DSLR camera (ref. my post here and here).

Spoiler

 

[voodooless]

Bokeh is a camera and lens function. It’s the creative arsenal of the artist, not the one making the reproduction print to hang on your wall.

For me the analogy doesn’t work because if this.

 

[Neuro]

Hello OP @Neuro,

Since I really enjoy not only amateur-audio-DIY-based music listening but also photographing using nice DSLR camera plus excellent lenses, your analogy of "sound bokeh" is very much interesting (and sound rather familiar) for me; ("bokeh" in photography is intentional and/or non-intentional out-of-focus/blurry in whole and/or specific portion of image.)


Yes...
After reading your initial post, now I feel that my recent inquiry regarding "3D sound perspectives" (ref. here #124) given by my present/latest audio setup in my own listening /acoustic environments would be somewhat, more or less, dependent on your mentioned "sound bokeh" of my present sound perspectives, I assume.

BTW, July last year, I posted one typical photo with beautiful (and rather intensive) "bokeh" background taken by CANON EF24-105mm F4L IS II USM lens attached to CANON EOS 5D Mark IV DSLR camera (ref. my post here and here).

Spoiler

View attachment 508456

The unsharp background enhances the flame. Perfect bokeh.
Just a flame without the background it is as boring as perceiving direct sound in an anechoic chamber.
Does bokeh come from Japanese?
Nice sound bokeh is like a work of art based on physics, never exactly duplicating the original sound based on physics .
Optimal sound reflections gives the right sound bokeh. This is discussed by Barron. 1998? and Toole /Olive 1986?

Neuro

 

[Juhazi]

I think that I understand and accept the OP's audio related associations, which I am familiar with, but dislike adapting new terminology from another context. And bokeh seems to be a mishmash of several effects and techniques that enhance the published final image... Well, ok for coffee table talk.

The major difference between photo/video and audio is that audio is so hugely morphed by reproduction system and environment (speakers and room). Photography has deliberately used many tricks to modify the image all the time - from exposure time, film grain, lens aperture to dark room or digital processing effects (photography is my long time hobby too).

A published photo appears practically similar to everyone who looks at it. Unlike audio release.

"Live" binocular visual perception of surrounding environment is closer to binaural hearing than looking at photos. Unconcious eye movements, brains doing focusing, blurring, contrast adjustment, filtering, etc. continuosly

 

[ahofer]

Toole/Olives spinorama provides partially relevant but not sufficient information for optimal sound bokeh.
The subjective perception in the listening position of a speaker's direct sound, dispersion patterns, the reflections in the room require more focus on more relevant measurable data.
As a senior neuroscientist with focus on brain tumors, brain anatomy and functional brain imaging, I find it strange that so little is done by colleagues with respect to how physics affects neurophysiology and neuropsychology. After reading Toole's last three editions of Sound Reproduction and downloading thousands of relevant studies I have concluded that there are many relevant areas which are suboptimally investigated and not described.
At present I have the basis for a number of review articles and very interesting studies. I lack a sounding board with some physical experience and preferably some knowledge in neurophysiology/neuropsychology. My research is published through The Karoliska Institut Sweden. Any suggestions?

Neuro

Have you read Daniel Levitin’s book “Your Brain on Music”? It’s about the music, not the reproduction, but he might be an interesting correspondent.

As for the “bokeh” you describe, I’m not sure. In an image, Bokeh mimics the selective focus that our visual senses have naturally.

A lot of what people seem to like in inaccurate modes of reproduction (ie old tubes, vinyl, tape) is an added background noise that perhaps masks details. Details in the way it is difficult for a photograph to capture the experience of, say, a stone wall, where our eyes can look into the dark nooks as well as the exposed portions but the conventional camera struggles with reproducing that experience and the picture is found wanting.

And I’ve always thought one of the added experiences of vinyl is the ‘likeness’ of the needle’s instability on the surface, sometimes a little microphonic relative to things in the room (bass, footsteps).

In any event, our brains perceive and react to different stimuli differently, making up or suppressing information in (what we presume are) adaptive ways. Once you’ve ever heard your heartbeat in your ear, and then wondered why you don’t most of the time, this becomes very clear. Or perhaps looked at those ‘completeness’ visual illusions, where your brain fills in the details.

I’m blathering on, but I wonder how well these analogies travel across senses. Is there “olfactory bokeh”?

 

[dualazmak]

The unsharp background enhances the flame. Perfect bokeh. Just a flame without it is as boring as direct sound in an anechoic chamber.
Does bokeh come from Japanese?
Nice sound bokeh is like a work of art based on physics, never exactly duplicating the original sound based on physics .

Neuro

I fully agree.

And, "bokeh" comes from a Japanese word "boké" (noun, and adjective), "boké-ru" is intransitive verb, "boké-saseru" is trasitive verb. If I say "kono lens wa haikei wo kirei-ni boké-saseru." it means "This lens gives beautiful bokeh in background".

 

[AndyMorris]

Bokeh is a camera and lens function. It’s the creative arsenal of the artist, not the one making the reproduction print to hang on your wall.

For me the analogy doesn’t work because if this.

Would the Bokeh be the producer/ sound engineer? Taken to extreme perhaps by the Dub reggae of Lee Perry or the almost entirely reconstructed sounds of Drum And Bass?

 

[ahofer]

I fully agree.

And, "bokeh" comes from a Japanese word "boké" (noun, and adjective), "boké-ru" is intransitive verb, "boké-saseru" is trasitive verb. if I say "kono lens wa haikei wo kirei-ni boké-saseru." it means "This lens gives beautiful bokeh in background".

Is it the same “boke” as the Japanese use for jet lag? Doesn’t it sort of have a ‘senility’ implication?

 

[Neuro]

I think that I understand and accept the OP's audio related associations, which I am familiar with, but dislike adapting new terminology from another context. And bokeh seems to be a mishmash of several effects and techniques that enhance the published final image... Well, ok for coffee table talk.

The major difference between photo/video and audio is that audio is so hugely morphed by reproduction system and environment (speakers and room). Photography has deliberately used many tricks to modify the image all the time - from exposure time, film grain, lens aperture to black room or digital processing effects (photography is my long time hobby too).

A published photo appears practically similar to everyone who looks at it. Unlike audio release.

"Live" binocular visual perception of surrounding environment is closer to binaural hearing than looking at photos. Unconcious eye movements, brains doing focusing, blurring, contrast adjustment, filtering, etc. continuosly

Visual perception is partly similar to how we hear.
The eye has a sharp angle of about 2 degrees. Unlike hearing, the eye can sweep over interesting visible objects many times. In the brain, an almost 180 degree perceived image of the environment is created from these 2 degree images.
We have a segmented vision up to 60 images/s.

Hearing has a similar segmented perception. It is a misconception that all hearing is live without relation to previously heard sounds.
The precedence effect is based on that the brain, the temporal lobes, comparing with recently heard sounds and with sounds stored in the frontal lobes.
The localization of prominent sounds occurs in the brainstem and remains until a new prominent sound is identified.
The segmented hearings resolution is maximum 500 percepts/s (click sounds) but usually fewer.

 

[dualazmak]

Is it the same “boke” as the Japanese use for jet lag? Doesn’t it sort of have a ‘senility’ implication?

Yes, partially true/right...
The term "boké" in Japanese also has meanings of "brain bokeh", "brain fog", and/or "blur in brain recognition", "cognitive impairments"...
So, sometimes "light/mild brain bokeh" means "mild cognitive impairments (MCI)".

 

[Neuro]

Have you read Daniel Levitin’s book “Your Brain on Music”? It’s about the music, not the reproduction, but he might be an interesting correspondent.

As for the “bokeh” you describe, I’m not sure. In an image, Bokeh mimics the selective focus that our visual senses have naturally.

A lot of what people seem to like in inaccurate modes of reproduction (ie old tubes, vinyl, tape) is an added background noise that perhaps masks details. Details in the way it is difficult for a photograph to capture the experience of, say, a stone wall, where our eyes can look into the dark nooks as well as the exposed portions but the conventional camera struggles with reproducing that experience and the picture is found wanting.

And I’ve always thought one of the added experiences of vinyl is the ‘likeness’ of the needle’s instability on the surface, sometimes a little microphonic relative to things in the room (bass, footsteps).

In any event, our brains perceive and react to different stimuli differently, making up or suppressing information in (what we presume are) adaptive ways. Once you’ve ever heard your heartbeat in your ear, and then wondered why you don’t most of the time, this becomes very clear. Or perhaps looked at those ‘completeness’ visual illusions, where your brain fills in the details.

I’m blathering on, but I wonder how well these analogies travel across senses. Is there “olfactory bokeh”?

Yes I have it. But he is more into recording if remember correctly?
Wine with good cheese or wine with good olive oil gives a completely different bokeh than just drinking the wine without anything to eat.

Neuro

 

[dualazmak]

Just for your reference and interests...

In photography world, some lenses are good at giving beautiful "rear bokeh" (bokeh in rear of focal plane), some lenses are good at giving "front bokeh" (bokeh in front of focal plane), and some excellent lenses are good at giving both of "rear bokeh and front bokeh".

 

[Neuro]

Yes, partially true/right...
The term "boké" in Japanese also has meanings of "brain bokeh", "brain fog", and/or "blur in brain recognition"...

Boke seems to be more negative in Japanese. In my interpretation, boke means a secondary positive reinforcement of a primary perception.
Reflexes give a secondary positive coloration of the primary direct sound under optimal conditions.

 

[dualazmak]

Boke seems to be more negative in Japanese. In my interpretation, boke means a secondary positive reinforcement of a primary perception.
Reflexes give a secondary positive coloration of the primary direct sound under optimal conditions.

In healthcare field/aspects, you are partially right.

Spoiler

I have been working, doing research as Ph.D., in medical imaging fields for long years; CT, MRI, PET, SPECT, US, X-ray, endoscopy, etc. just like you have been doing the same; your avatar image tells it...

In art and photography world, however, "boké" and "boka-shi" (the state of being bokeh-ed) have no negative expression/sense at all; it is one of the nice aspects of Japanese arts and culture...

 

[ahofer]

In healthcare field/aspects, you are partially right.

Spoiler

(I have been working, doing research as Ph.D., in medical imaging fields for long years; CT, MRI, PET, SPECT, US, X-ray, endoscopy, etc. just like you have been doing the same...)

In art and photography world, however, "boké" and "boka-shi" (the state of being bokeh-ed) have no negative expression/sense at all; it is one of the nice aspects of Japanese arts and culture...

Indeed. This is a sumi painting I own that comes to mind. My Japanese is rudimentary, but I have trouble making out many of the characters and kana here in the first place.

I own another one that is just a few lines, described as something like “the evaporation of the first layer of snow”.

PS- I should have thought of running this through AI:

## Right Section: "Evening Glow at a Fishing Village"

The text on the right describes a serene scene of a fishing village as the sun sets.

* **Japanese (Transcription):** 漁村夕照
夕照の
あとのなごりに
入合の
かねにまかせて
帰る舟人
* **Romanization:** *Gyoson Sekishou*
*Yuubae no / ato no nagori ni / iriai no / kane ni makasete / kaeru funabito*
* **Translation:**
**The Evening Glow at the Fishing Village**
In the lingering traces of the sunset's glow,
following the sound of the evening temple bell,
the fishermen turn their boats toward home.

---

## Left Section: "Wild Geese Descending to Sandbar"

The text on the left refers to the sight of geese returning to rest, a common metaphor for peace and return.

* **Japanese (Transcription):**
平沙落雁
さし昇る
月をまたでや
跡たれて
おつるもはやき
をしへののかり
* **Romanization:** *Heisa Rakugan*
*Sashinoboru / tsuki o matade ya / ato tarete / otsuru mo hayaki / oshie no no kari*
* **Translation:**
**Wild Geese Descending to the Flat Sandbar**
Without waiting for the rising moon to appear,
leaving their trails behind,
the wild geese of the teaching [the Dharma]
descend swiftly to the fields.