# How sight influences what we hear



## 3dbinCanada (Sep 13, 2012)

Try this. This clearly demonstrates sight bias and why its so important to use blind listening tests to determine which component produces the best sound.

http://youtu.be/G-lN8vWm3m0


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## Lumen (May 17, 2014)

But, but, but.... speaker lips don't move :rofl2:


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## willis7469 (Jan 31, 2014)

That's why I close my eyes when I'm listening. That way, my JBL's sound like Wilson watt puppies!


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## 3dbinCanada (Sep 13, 2012)

willis7469 said:


> That's why I close my eyes when I'm listening. That way, my JBL's sound like Wilson watt puppies!


:T Your JBLs measure better then Wilson Watt Puppys so I would keep my eyes open.


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## willis7469 (Jan 31, 2014)

3dbinCanada said:


> :T Your JBLs measure better then Wilson Watt Puppys so I would keep my eyes open.


 lol. Thanks Charlie. I do still enjoy them even after all this time.


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## willis7469 (Jan 31, 2014)

If you wanna try something different (maybe you have before). Put on a BD of a movie with a fairly busy soundtrack, and turn off the display. (No it's not the same as closing your eyes). You'll really notice how the visual cues affect the perception. Not to say all the imaging isn't there, it's just, shall we say, enhanced. I find if its a soundtrack that I know well, I can better evaluate speaker placement and toe/angles etc. then re watch with it on to fine tune. If nothing else, it's something different to do with your system.


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## Talley (Dec 8, 2010)

I always close my eyes when I listen too. My eyes causes too much distractions.


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## 3dbinCanada (Sep 13, 2012)

I fight to keep my eyes open but I ALWAYS end up nodding off from poor sleeping habits


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## Lumen (May 17, 2014)

Thought experiment...

Roughly 10x more brainpower is devoted to vision than to hearing. *When you close your eyes, is that brainpower then freed for hearing use? *


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## 3dbinCanada (Sep 13, 2012)

BlueRockinLou said:


> Thought experiment...
> 
> Roughly 10x more brainpower is devoted to vision than to hearing. *When you close your eyes, is that brainpower then freed for hearing use? *


What it means is that the 10% of brain power is turned off so that what you are hearing is not being influenced by sight or that 10% of brain power.


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## Dwight Angus (Dec 17, 2007)

There maybe something to this. I am listening to more 2 channel music lately & I prefer to listen with eyes closed. Must be visual distractions


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## Lumen (May 17, 2014)

Then again, I could argue the other side of the coin: in a finely-tuned two-channel system, the sound stage and imaging (SS&I) are so convincing that they're quite immune to sighted listening. Images are spread in and around the speakers in a reach-out-and-touch fashion. A finely tuned stereo can also deliver startle factor--the ability of the system to convincingly reproduce a sound which elicits the same listener response as the real thing (e.g. a barking dog or plucked guitar string).


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## 3dbinCanada (Sep 13, 2012)

BlueRockinLou said:


> Then again, I could argue the other side of the coin: in a finely-tuned two-channel system, the sound stage and imaging (SS&I) are so convincing that they're quite immune to sighted listening. Images are spread in and around the speakers in a reach-out-and-touch fashion. A finely tuned stereo can also deliver startle factor--the ability of the system to convincingly reproduce a sound which elicits the same listener response as the real thing (e.g. a barking dog or plucked guitar string).


True enough.  My post was more in the context of comparing electronic components.


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## Lumen (May 17, 2014)

opssign: fftopic2: 

My apologies. :R


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## kevin360 (Oct 4, 2012)

BlueRockinLou said:


> Thought experiment...
> 
> Roughly 10x more brainpower is devoted to vision than to hearing. *When you close your eyes, is that brainpower then freed for hearing use? *


No, it doesn't work that way. Brain areas are specialized processing modules and over 40 such modules are dedicated to aspects of vision. If one were truly blind, with no visual information streaming into the brain via the optic nerves, _then_ the plasticity of the brain would result in the reallocation of portions of those areas to other functions. 

This discussion is missing the point of the McGurk Effect. It has nothing to do with 'brain power'. Our brains _create_ what we perceive - perceiving is not a passive process. In fact, perceptually speaking, we actually live in the past (we're talking milliseconds here, but...). Anyway, the visual and auditory processing modules are connected via the inferior parietal lobule (as well as directly, but synesthesia is a topic for another discussion), which is how visual cues override auditory data in the creation of our perception of sound. Of course, we don't need visual input to mess up auditory perception; in fact, there are many auditory illusions which don't involve vision.

Although the McGurk Effect is interesting (such illusions inform us about the rules of perceptual creation), what happens in sighted listening evaluations is actually somewhat different. The problem with seeing what one is evaluating is that we cannot help but have prejudices regarding brands - this doesn't point out a weakness which must be overcome, but is simply a matter of how our brains are designed. Expectation bias is driven by the mesolimbic dopamine system - predict a reward and chemistry works toward making it a self-fulfilling prophesy (in advance of experiencing the stimulus). Efficiency and quick decision making are critical features for brains, and shortcuts improve both. 

We are all human and all of us have brains which operate mostly (an understatement) beyond conscious awareness, let alone control (and necessarily so). Recognizing the aforementioned facts suggests the importance of blind listening evaluations, but, unfortunately, things are not really that simple. From our brain's perspective, that's like stepping into a boxing ring with one's hands tied behind his back (again, influencing brain chemistry). Ergo, the problem is actually intractable. There simply is no way to conduct a listening evaluation objectively, and bench tests only go so far.

We're stuck with subjectivity and bias. The best we can do is be aware that such influences exist. Long term, the bias under consideration in this thread fades, but that hardly helps us in a single comparative evaluation. It always pleases me to see threads like this, but I think the only take away we should carry is the awareness of our nature. To that, I'd like to add the recognition that perception is an actively creative process.

-----

BTW, here's a simple visual illusion. It merely involves the perception of color and hinges upon the fact that context matters. Rules drive our perception. I can tell you that the squares in the center are the same color. You can watch it be proven. You can prove it to yourself. You can do this repeatedly, yet you can _*never*_ see the colors as they truly are in the context of the surrounding colored squares. Your brain knows that the squares of the same color on the shaded face will be darker than those on the fully lit face. Therefore, the same color must actually be a darkened lighter color on the shaded face, so that's the perception your brain creates. That perceptual creation is simply beyond conscious control. It is impervious to top-down influence. It is a hard-coded rule that drives an erroneous perception. Perception did not evolve for veracity; it merely must be useful as a user interface with physical reality.


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## Lumen (May 17, 2014)

That's an intriguing post, Kevin. I imagine/perceive I'll need a slice of time-space to fully comprehend all it has to offer. Just became aware of your other perceptual discussions in the "Listening for Differences" thread over in the Two Channel Audio Forum. My interest is mirrored there as well. I'm unsure how to respond except to leave my response as it stands thus far in my perception of the imagery it attempts to actively convey! 

Sent from my iPad using HTShack


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## kevin360 (Oct 4, 2012)

Hey, it gets a bit freakier than my previous posts imply (although I did mention living in the past, which applies to this comment). With the McGurk Effect, the visual information which overrides what one hears takes longer to process than the audio information which is being modified by what one sees. In other words, our brains wait until they have all of the information on what just happened before creating the experience of what just happened.

Here's a neat little presentation by David Eagleman on the subject of time perception, etc.


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## pratikvdoshi (May 11, 2015)

kul


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## pratikvdoshi (May 11, 2015)

it does influence imo


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