WhiskeySix

I've also taken some audio engineering classes back in the day, so I know exactly what you're talking about. You're right, there is a hell of a lot of signal processing happening to augment the physical speaker layout. I'm just saying that you absolutely can discern the different sources in 5.1 headphones. Specifically, you can observe this with one of the 'test' patterns that's provided with w/ Audigy sound cards (Or the THX optimizer works the same way). It plays discrete sounds over each of the 6 channels... a woman's voice says "Front Left... Front Right... Back Right..." etc. from the coresponding channel. During that test, it's quite simple to discern Front Right from Back Right. Granted, it's not a huge difference (FR sounds like it's coming from about 2:00, and BR sounds like it's coming from 4:00), but it IS different from stereo headphones.


Cliff Claven factoid of the day: I saw a thing on the National Geographic channel last night about Raptors (birds of prey)... It was pretty cool, but one thing that stuck out to me was that some owls hunt using sound - They can locate mice scurrying under a foot of snow!!! The Great Grey Owl has face feathers that act as a parabolic mic). What's really crazy is that they localize not only the horizontal plane as humans do, but also in vertical space!! It turns out their right ear is pointed up slightly while the left is pointed down a little.. it let's their brain triangulate - as if they had a third ear

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sc1ence

in our lab, we used exactly that type of program to test people, but intstaid of telling them which sound was playing from where, we used the sound of a duck quacking through each driver (people can localize natural sounds better). they performed no better than people with stereo headphones and no better than chance for up down, front back. while this data is not published it seemed reliable enough for us to decide that 5.1 headhpones are not worth using in our localization experiments. back to recording hrtf and having a big sound room setup.

we used a sample of 3 people that each had no training prior to use. i wonder if people could be trained to pick up the subtle diferences that would be present? I also wonder if the software for the headphones still needs development to work better?

meh, im going to stick with visual perception and leave the auditory stuff to my wife.

if only i could keep the headphones and use them for gaming, they sounded very nice.

very cool factoid btw

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WhiskeySix

hm, no kidding... that's really surprising... <shrug>

What SW is it? You know what this sounds like? It sounds like the perfect excuse to get BF2, an Audigy sound card, and some 5.1 eargoggles running in the lab

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sc1ence

thinking more about this on the ride home. i bet there is an ear related transfer function simmilar to the hrtf. if the drivers are consistantly located in the same place relative to the ear. the different parts of the outer ear should shape the sound in a reliable way. people with some feedback training should be able to locate sounds.

software was hacked version of the sb software, pretty much just go in and pick out the sounds that should be played and replaced them with our sounds.

the last thing i need at work is bf2 / bf2142. its bad enough I have access to these forums lol.

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WhiskeySix

so after playing w/ stereo headphones for 2 weeks, I got my replacement 5.1's in last night and retested them with this thread in mind. It's not as directional as I previously remembered (with the "woman's voice" test)... the fronts do sound like they're at about 2:00 (slightly forward) but the "back" speakers sound like their barely beyond 3:00. ("Center" does sound like it's in front).

But then in game, it makes such a huge difference... so it really is all about SW emulation combined with the immersion factor (being able to turn your virtual head in-game and have the sound go where you expect it... following the visual scene)

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peardog

Ok... Make and Model of Phones?? I am in the marked for USB Headset for Gaming and am interested in the Gaming Crew to steer me in the right direction.!!.

Thanks!

Peardog

Sir_Brass

Let me put it this way: I have essentially been my own test subject. For YEARS I used a stereo headset, utilizing headphone surround optimization (kind of an early hrtf) through my soundcard. I thought I was doing alright.

THEN I bought a surround headset, and the difference in localization was like the difference between night and DAY. I literally heard DIRECTION in the sounds, instead of having to track around to find the point where the sound was loudest. I was able to kill knifers that were about to knife me from behind b/c they drew their knives about a meter away, I heard the sound BEHIND ME and in a certain direction (either left or right), spun and knowing WHERE they were coming from, knew where to fire. Knifers died, I laughed.

Sc1ence, as an engineer, I appreciate the solid testing that you've done, however there's something in engineering that pure science doesn't seem to cover: even if all the data says one thing, if results prove something different, then that's what's proven. Or to put into an old saying, "The proof is in the pudding." I've observed a world of difference in the ability to localize sounds with a surround headset compared to a stereo headset. Sound quality is not the issue, but sound localization.

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|TG-Irr|Hiram_Yorik
Games: GRAW, BF2142, Oblivion, FarCry, Empire At War, R6:RVS, KotOR, KotOR2, MW4: Mercs, FEAR (XP)




*Hiss* "Oh...crap!" *BLAM* "I'm down....MEDIC!!"

DirtyLude: "If we kill him and eat his heart, his magic will be ours."

MDFubar

Maybe it is just my perception, but I know that if you are in the game and fire a weapon I can usually distinguish what direction it came from. Not being hit, the directional indicator does not come up. I can also usually tell where a verhicle is in reference to my location. Maybe just my perception, but sure seems real to me.......could be the optional equipment that i use when I play sometimes..........aww you know..

sc1ence

I am fully willing to entertain the hypothesis that directionality can be perceived using 5.1 headphones. I would agree that the anecdotal evidence is compelling and deserves a close look.

theoretically, it seems plausable that there is an ear related transfer function that is shaping the sound in such a way that the sound is permitting directionality.

let me be clear though, there is no pysiology in the ear that perceives direction. you *can* perceive intensity. when you perceive intensity across a field (intensity mapping across space), directionality should be evident with a small sample of the feild. that is why moving your aimpoint in fps gives you directionality of sound with stereo headphones.

i worry that fidelity is being confounded with stereo vs 5.1s. but again, most psychological science starts with anectdotal evidence. clearly this deserves closer inspection.

*note to self - write a grant proposal for upgrading vid card to run bf2142 in lab...*



thanks for the input fellas. it is much appreciated.

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WhiskeySix

I have Medusa 5.1's, but there's a few other brands out there as well... if you do a search for "medusa", you'll find a few threads discussing headset pros/cons:

http://www.tacticalgamer.com/search.php?searchid=540854

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Sir_Brass

I would pose this hypoethesis, then. Seeing as there is nothing in the EAR that percieves directionality, I say that there's something in the brain which DOES. Possibly some kalman-filter like process by which we localize sound. The stronger it is relied on, the more accurate it is. This is observed with blind people who have been relying on their other senses for years finding their way by sound in some amazing ways.

I also pose this, that somehow, the discrete 5-channel sound transmitted to the ears in 5.1 surround headsets is better used by the brain to determine localization than it can with stereo headsets. This is observed by the anecdotal evidence we've just discussed.

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|TG-Irr|Hiram_Yorik
Games: GRAW, BF2142, Oblivion, FarCry, Empire At War, R6:RVS, KotOR, KotOR2, MW4: Mercs, FEAR (XP)




*Hiss* "Oh...crap!" *BLAM* "I'm down....MEDIC!!"

DirtyLude: "If we kill him and eat his heart, his magic will be ours."

WhiskeySix

yeah, I think it's based on the fact that, however small, there IS a discernible difference in directionality between the front, center, and rear sources. My best guess is that the visual input (and situational awareness in an immersive virtual world) basically trains the brain on how to map what it hears. Your brain basically normalizes based on the new inputs. Like if you wear a helmet (football, motorcycle, etc), you can still perceive directionality just fine even though your ears are hearing through a completely different filter.

Perhaps it's similar to how your eyes "adapt" to sunglasses: your brain can still perceive blue, red, green, and white - even though that's not really what the eye is seeing. (Thus when you take of the tinted glasses everything seems yellowish if you had blue tinted shads, or blueish if you had brown-tinting... it's still using the 'normalized' preset, and it takes a moment for them to recalibrate)

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MDFubar

HMMMMM, I truly do not know if the headphones that I use now are 5.1. This particular set that I am using I actually got when I purchased BF2 on the original release....a freeby! YEAH! I have another set that is....I think Logitec, but not 100% sure. I really didn't notice a difference, the freebies are lighter. I suggest that you also try them on and make sure they are comfortable, wearing them for 2, 3, 4, 5, or more hours can take a toll if they do not fit right.

sc1ence

looked a little deeper into this. seems there should be what I referred to as an ear related transfer function. it is a specific part of the hrtf. pinna reflectance is unique for each individual. their experience with the way their ears shape sounds does specify sound source location. so 5.1 headphones should be able to help you localize sound to the extent that he headphones allow sound to be reflected off your ears. if the headphones mash your ears then you will probably need to experience sound source localization with them in that mashed posiiton for a while before you are able to localize sound with high accuracy. I suspect the signal detection experiments I ran did not allow people to use their pinna reflectance in the absence of other parts of the hrtf.

my wife is starting to look into this and will probably be conducting some cool experiments. i study vision and general perceptual theory, she studies audition and general perceptual theory.

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