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Do the 5.1 Stereo Headphones Really Work?
Tamor asks: "Zalman, the company behind some extremely high quality PC noise-reducing products are now selling real 5.1 surround sound headphones. The surround effect is achieved by placing 3 drivers in each ear-piece. As a geek-with-young-family this product's pushing all the right buttons for me, it looks cool, and means I can finally achieve surround sound without waking the kids. Or does it? I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other. If your left ear only hears the left 3 channels, and your right ear only hears the right 3 channels isn't this making it more difficult for spatial placement to happen? Do you know if/how these are achieving surround effect if each ear is only hearing half of the audio field?"
Does anyone have personal experience with these? They seem pretty cheap from Newegg, and I'd get a pair if I can get a positive review...
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I'm missing something with this category.
Why not call the manufacturer and ask them how they do it? Maybe get a set from them to demo and test. See if YOU can hear the difference.
----- LoboSoft specializes in Digital Language Lab
To my understanding, your ear places sounds spatially by volume. It sounds louder in the closer ear.
Beyond that, unless you have a really big head, the difference in arrival time to each ear is less than a microsecond. That is surely too small for your brain to comprehend.
This signiture copied from somewhere.
The Headphones are "smart" enough to create an appropriate delay, per channel, to cause that spatial effect you refer to.
10b||~10b -- aah, what a question!
reviews found at:
bigbrui.com, overclockersclub.com, modthebox.com, pcextreme.net, Tom's Hardware, AnandTech.com, etc...
This month's CPU magazine has a review of these headphones. Don't recall the specifics, but they received a good review. The reviewer found them to be much better than stereo headphones during gaming sessions as you could hear sounds from all directions. But the sound quality for DVD movie playback wasn't so hot.
There might be a copy of the review on their website (no I don't have a URL, use a search engine).
It probably places sound in the same way those false surround sound systems place sound, by mimicking the left channel in the right ear and vice-versa, but at a different volume level. Distance can easily be faked with volume.
I don't imagine this is overly difficult, provided there are at least two speakers in each headphone. I'm interested, for sure!
a friend of mine has these. i havent tried them yet, but he's been raving about them.
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But the Zalman product page that you linked to in your post had links to several online reviews. Were those insufficient? I found them to give me all the information that I would need to make a $40 purchase...
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Where did you find those other three ears? Please, I'd love to find out.
It's a gimmick, christ. You only have two ears; it doesn't matter where the sound is coming from. Direction is simulated by the recording, not the headphones.
--
I've been very tempted by these, but haven't been able to find many reviews. (I haven't looked for a few months though. Maybe there's more information available now.)
I'm looking for a HEPA media filter for my TV. I'm alergic to reality shows.
These guys who make the headphones, they sort of do this for a living, so they probably know more about it than you. That is: Anything you can come up with in the first five minutes after hearing about the idea, they rely on already having come up with.
This isnt something that somebody decided one weekend would be neat, and so slapped three headphones together with duct-tape and started talking to magazines. They developed, designed, tested, talked to various manufacturers, looked into methods of distribution. Do you think that in all that time, nobody would have considered how surround sound would be best implimented in a pair of headphones?
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Just because the right can is on your right ear doesn't mean it can't play something from a left channel. There are three drivers in each can, remember? Even if there weren't, you could still mix the left channel into the right can at the appropriate delay and volume.
Although the tests took place in a sound chamber, they were kind enough to give me a demo tape -- and this tape is amazing. They demo about 5 different voices (simultaneous ATC conversations), both flat and spatialized. Flat, it's impossible to differentiate them. With the convolvotron, it was possible and easy to track each conversation separately. Each one sounded like it came from a different place.
This was early 90s. Processing power has certainly increased since then. It should be possible, and relatively cheap, for someone to use Convolvotron-like technology to convert a 5.1-channel signal to spatialized L-and-R ones for use with regular headphones. There shouldn't be a need for special headphones.
Lots of Google hits for "Convolvotron". Enjoy.
Left-right stereo has been here a long time and it works wonders with headphones. No doubt about that.
/. fashion, I'm posting this without actually having experienced 5.1 headphones with more than one speaker on each side. I'd like to try though.
And since any sound arrives at your two cochleas, it must be possible to simulate any sound position just by exciting your two ears, preferably with in-ear phones.
But I have a hinch that cues about whether a sound is at the back or front come subconsciously from:
1. Turning your head and registering the changes in sound.
2. Echoes and reverb. This only works if you know and 'feel' the room. (*)
3. Changes in frequency response due to the structure of your ears. This only works for sounds you know.
As the headphones are fixed to your head the first, and probably the most important, cue disappears. The room where the sounds were recorded does not match the room you're in, so the second cue disappears. And finally you will be listening to new, unknown sounds. There goes the third cue as well.
But in true
(*) While I'm listening with isolating in-ear buds, it is strange that the sound changes dramatically the moment I enter a building from the outside. Hard to explain by reverb and echo as there is little sound leakage from the buds to the outside and vice-versa.
Flourescent (adj): smelling like ground wheat.
I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other.
Yes, this information is used for left/right locating. But AFAIK (IANAES, I am not an ear specialist) also interference caused by sonic reflections from your shoulders are needed for locating whether a sound comes from above or below. I don't know how the distinguishes front/rear locating, though.
I tried a pair of Sennheiser headphones some five or six years ago.
I believe they cost about $600 or even more, and they had really great sound. I don't have much experience in headphones, so I'm not sure if this basically would apply to any $200+ set... ?
Anyway, they lacked one big thing: The subwoofer. Half the surround experience is the feeling of the ultra low frequency in your stomach, and earphones just wont do that.
Many many moons ago, when I was doing video production work, I received a sample CD from an audio library collection billed as "3D-sound".
I don't know how the stuff was recorded, but it was recorded such that you really could localize the sound, in space, in 3 dimensions, from regular ol' stereo headphones. The most memorable tracks on the CD was of someone getting a haircut. You could hear *where* the scissors "were" around your head. You could tell where the hairdryer was blowing. Not just left-or-right, but *around* your head. The stuff was amazing.
I'm guessing that not just volume and left-or-right determines where you hear things, but phase as well.
But, anyhoo, the point being that you can very likely achieve good surround-sound sounding stuff with just one speaker per ear, and not three.
Ed R.Zahurak
You know, oblivion keeps looking better every day.
In 5.1 the ".1" is a subwoofer. These headphones can't possibly be 5.1
I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other.
Knowing nothing about human hearing we can almost rule out this conjecture. Noise travels at about 761.207051 mph and your ears are about a foot apart.
That means there is a difference of 895.706603 microseconds between when the first ear would hear the sound and when the second one would.
This is 1/1116th of a second, meaning that if your brain 'ticks' subconsciously at anything less than 1100 hertz its timing would be too coarse to catch this minute difference.
The brain, in fact, ticks a couple of orders of magnitude slower than this, and moreover the theoretical maximum a single neuron can tick is 2000 hertz, so there would have to be ~0 ms delay in signal propagation between neurons, and the signals would have to make a straight line from each ear toward the area in which the signal is to be processed in order for comparison to occur together with pertinent timing information. (The brain, of course, is not so precisely wired that it could take into account some kind of fixed minute differences in timing among various input sources.)
So we can rule that out. The next idea continues with your implicit assumption that each ear is, logically, a fixed point of input, with the brain reconstructing all spatial information. (Ears, in fact, have a complex set of ridges precisely because they do convey spatial information)
But if we thought of ears as mere fixed points of frequency/amplitude sampling, we might be tempted to think that all spatial information is reconstructed from minute differences in amplitude -- the ear nearer the sound source would hear it more loudly. We can also eliminate this conjecture because the two spheres of possible sound location a given distance from each ear intersect not in one point but a whole arc of possible places. What I mean is, if all your brain knew is : "Ear 1 hears source at A loudness and ear 2 hears source at B loudness, and ear1 is at (x1, y1) and ear2 is at (x2, y2)", then, together with information about how sound loses amplitude with the square of the distance it travels and inversely with the frequency (assume the pertinent natural laws are hard-wired), it could produce the fact: A-ha! The source must be 10 feet from ear1 but 10.23 feet from ear2.
The problem is, there is not ONE point that fits those descriptions, but an infinitely many.
If your ears were just input points, then, if you start playing a sound file on the computer in front if you, it should sound the same with your eyes closed now as it would if you turned around and heard it from behind: Each ear hears an equally loud sound, only now from behind instead of in front. The problem is, you can tell that it's from behind and not from in front of you! (Try a double-blind test if you're not sure -- place one speaker dead in front of you and one speaker an equal distance dead behind you, write a script to randomly play either full left or full right balance, close your eyes and listen to the random tests; you'll always be able to tell where the sound source is coming from.).
Okay, so now we've long-windedly debunked the naive assumptions about how the brain might reconstruct spatial information. How does it?
Beats me.
I haven't heard about this product yet, but it's now on the list. I'm fascinated by stereo sound, as for the first 26 years of my life I've had only one ear. I just had the other operated on this past year and I'm starting to experience spatialization and stereo sound for the first time ever. It's easier with headphones because the vibration helps with the effect. Still have to crank the right channel a bit, tho'.
Have you ever heard of an effect called interference? I allows you to detect changes in waves of wave length shorter than you can sample. And since most people have two ears, comparing the two inputs should be fairly simple for the brain.
And also there is fact that the brain does not 'tic' not at all. At least on in the way a centralised von-Neumann architecture does. Don't quote findings on neural response, since they disallow for the fact that the nerve input may be parralised (ever count the nerve strands that come in from the inner ear? Talk to somebody who configures Cochlea-implants for a livin)
Actually tests with a head dummy support the theory that nose is important to differentiating between sound from the front and the back, because the distortion is different. (sorry my reference is pre-internet)
But then IANAAE (I am not a audio engineer)
mfg lutz
Not quite the same thing, but has anyone had any experience with this? Dolby says, "Best of all, it works with any stereo headphones", yet they claim it "isn't some kind of pseudo-surround effect: it's for real". Hmmm...
I notice that the reviews tend to say that the sound was interesting in its effects, but not very high quality for things like movies and music.
Anyone else doing something similar, but with high quality sound, or is this too new? (Sorry, I'm not an audiophile, so I have no idea.)
"Those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded."
Why not call the manufacturer
Yeah, because a salesman would never lie to you in order to get a sale.
Personally, I'd wait until version 5.2 because we all know that .0 and .1 releases are unstable, and you certainly wouldn't want your ears falling off.
-- disclaimer: This absolutely the most retarded post I've ever made.
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I've worn hearing aids over the last 20 years or so, and I've come to the realization that sound and perception is a lot more than just what the ears hear. My hearing isn't that bad, but it's difficult to get along without them.
The first thing you have to realize, is it isn't just what your ears hear, it's the vibrations that you feel all over your body that affect your spatial perception. Think about it, if spatial perception was just the difference in sound arrival time between each ear there should be no way for you to tell whether a sound is coming from in front of your or behind you. Yet it's obvious when you close your eyes what direction it's coming from.
All sound is is air pressure changes. Your entire body is a hearing device. Your body can feel the sound waves hitting your front and back and can deduce direction pretty easily from that. Your skull makes a very good resonating cavity to collect and amplify these vibrations. Just go to a rave or live concert and feel the vibrations. One of the tests they always give me is bone conduction, where they put two transducers on my skull behind my ears. I can hear the sounds they produce almost as well as if it was audible coming through my ears.
I doubt the three transducers in each ear is worth the effect. I'd think it'd be much more successful if you had some sort of a band all the way around your head that would vibrate your skull from various directions. You need your ears for Clarity, to understand what you're hearing; but your skin and body can handle sound sensations. Even completely deaf people can sense sounds and directions through the vibrations.
I'd think true 5.1 is just unachievable through a simple pair of headphones, no matter how many in each ear. Granted it may still sound good, but still not as good as a good set of speakers and a subwoofer.
I found out the actual answer to my question, and no it isn't on Zalman's site or in the reviews, and yes I expect that they did think about this before putting a product out. The answer is that the pinna (the outer part of the ear) catches the sound and funnels it down to the ear-drum. The folds and curves of the pinna alter the waveform of the sound as its funneled, and this happens in different ways depending on the direction in which the sound enters the pinna. The brain picks up those differences and is able to tell whether a sound originated in front, behind, above, below etc. So that's how you're able to spatially place a sound you can only hear in one ear. Neat.
I forgot to add that it's the fact that everybody's outer ear has a uniquely different physical structure that apparently makes it so difficult to simulate surround sound in a way that works for everybody. Everybody's outer ear distorts the sound in a different way, so modulating the sound in a way that would make placement perfect for me wouldn't work for someone else at all.
I can't decide whether in posting this question I've learned more about hearing or about the mentality of people who didn't see that there's an interesting question here, even even though Zalman is obviously not selling hi-tech snake oil. It's widely known that human hearing uses the delay between hearing a sound in each ear and the relative volume at each ear to do some placement, but these headphones take all that away. I wonder if you could sort the responses to my question into geek and non-geek based on who saw that left the question "how the heck does it work then?", and those who just couldn't resist telling me I was dumb for even asking.
if you have 5.1 ears...
how long until
These headphones appear to be a simplification on head related transfer functions (HRTF) which has been an active area of research for many years.
For true HRTFs, you really only need a single speaker per ear. You then control interlevel differences (volume differences) between ears as well as interphase differences between ears simulated a sound from a 3D spatial location. The problem is that you also need to have a way of tracking the person's head location and position. If you can track the person's head location then the 3D spatial localization of sound is quite impressive.
It looks like these headphones attempt to approach the problem instead by positioning multiple speakers on each ear. The slight difference in position of the speakers is likely enough to create the delays necessary to change the phase just enough to simulate the 3D spatial localization. It obviously won't be as good since no head tracking is done, but definitely a lot cheaper.
well, swayed by the hype and the claims, i picked up a pair of isound 5.1 home theatre headphones. the deal sounded like a steal (around $40). well, packaging was sexy enough - the headphones come ensconed in velvet cloth, red ribbons, etc. you also get a mini-amplifier and all kinds of cables.
what you don't get, however, is good sound quality! there is hardly any clarity to the sound, and it is nowhere close to the output of my regular headphones - a mid-priced sennheiser and a reference sony model.
further, the 5.1 effect is hardly to be noticed. there is a cd/dvd switch on the cord, and independent controls for front, rear and center. fiddling around does improve things a bit (not the sound quality, but the 5.1 'feel'). but this pair certainly won't blow you off.
worse, i can't even plug it into by audigy platinum card - it has no optical/ spdif/ din input. and using the line-out inputs on the back of the card leads to horribly distorted sound. plus, it means i have to disconnect my cambridge soundworks setup every time i plug in this pair. so, as a novelty item, yep, go ahead and buy something like this. but don't expect too much from it.
or how about this: you could get hold of three pairs of good quality headphones and one pair of those huge headphones (used by helicopter pilots, for example). then maybe you could empty out the big one, desolder the small ones, and fit them in the big one's earcups - one towards the rear, one in center, one at front! not sure what the wiring will look like. and maybe u will need some amplification circuit, too.
but hey, if this works, you could start a new business - am sure there will be a lot of slashdot guys willing to buy such a pair - never mind if it looks bulky and gaudy!
I have noticed an audio phenomenon with a music synthesizer where a mono signal (both left and right channels of a headphone set receiving exactly the same signal) will produce a sound that travels from one ear to the other and back for about two seconds.
This happens only on one patch created at random with a Yamaha FM synthesizer TX-81Z model.
I have no idea as to how it happens except to guess that a certain combination of the phases of the different original operators is causing a 'trick of the ears'.
This observation leads me to believe that it is possible to use a stereo two-channel signal to create the illusion of sounds coming from various three dimensional points and being artifically positionally manipulated.
Whether or not the research has advanced to the point where audio positional manipulation can actually be done on inexpensive ($100) headphones is debatable. [in other words, does this product really work or is it just more bullshit from the stereo equipment industry?]
Does anyone remember early 1970's Pink Floyd concerts where screaming guitar solos would come swirling from the back of the auditorium, spin around the stage, and shoot up through the roof? No, it wasn't all the acid. It was the elaborate quadrophonic sound system and creative stage technicians and audio engineers they employed.
I'm wondering where the .1 is in 5.1. It's typically the discreet channel, widely known as the subwoofer channel.
How exactly do these earphones recreate that frequency range?
If all you have is a hammer, everything looks like a nail.
Strap on kidney belt that uses a solenoid to punch you in the gut with every bass thump? (probably not)
I imagine the bass channel is piped in equally to both ears along with the center channel. The reason they still call it "5.1" is probably to indicate that it takes 5.1 audio as input.
If a job's not worth doing, it's not worth doing right.
"Strap on kidney belt that uses a solenoid to punch you in the gut with every bass thump? (probably not)"
Hahahaha! *deep breath* HAHAHAHAHA!
One of us should patent that thing.
Man, that was good.
If all you have is a hammer, everything looks like a nail.
As a kid I had a "lazy" eye that didn't let me see in stereo for a while -- later than many kids have it.
Once I finally determined to actually wear my patch, I remember realizing that I could see depth so much better afterward. At this moment I'm not taking that for granted.
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