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Do the 5.1 Stereo Headphones Really Work?

Cliff posted about 11 years ago | from the living-up-to-the-hype dept.

Music 84

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?"

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FP! (-1, Offtopic)

Anonymous Coward | about 11 years ago | (#8091892)


Frothy Piss!

Personal experience? (0, Redundant)

Garthnak (110033) | about 11 years ago | (#8091897)

Does anyone have personal experience with these? They seem pretty cheap from Newegg [newegg.com] , and I'd get a pair if I can get a positive review...

Re:Personal experience? (1, Informative)

MImeKillEr (445828) | about 11 years ago | (#8091953)

I'd get a pair if I can get a positive review...

No, you won't. At least, not from Newegg. From their page:

ZALMAN ZM-RS6F Real Surround Sound Headphone -RETAIL

Model# ZM-RS6F
Item # N82E16836501001
Price: $39.99
In Stock: NO

Re:Personal experience? (1)

Garthnak (110033) | about 11 years ago | (#8091991)

Just because it's out of stock NOW doesn't mean it won't be in stock soon. They just came out. I believe that's what the "(ETA1/27/2004)" under the "In Stock: NO" means. That they're estimated to be in stock by tomorrow or so.

Re:Personal experience? (1)

MImeKillEr (445828) | about 11 years ago | (#8092160)

Ahh. Didn't see the ETA.

BTW, Zalman's product page [zalman.co.kr] has links to reviews (albeit, likely only positive ones).

Ask Slashdot? What about Ask the Manufacturer? (3, Insightful)

wolf- (54587) | about 11 years ago | (#8091927)

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.

Re:Ask Slashdot? What about Ask the Manufacturer? (0)

Anonymous Coward | about 11 years ago | (#8096587)

Why not call the manufacturer

Yeah, because a salesman would never lie to you in order to get a sale.

Re:Ask Slashdot? What about Ask the Manufacturer? (1)

buck_wild (447801) | about 11 years ago | (#8108019)

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?

Re:Ask Slashdot? What about Ask the Manufacturer? (2, Funny)

Dun Malg (230075) | about 11 years ago | (#8108146)

I'm wondering where the .1 is in 5.1. It's typically the discreet channel, widely known as the subwoofer channel.

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.

Re:Ask Slashdot? What about Ask the Manufacturer? (1)

buck_wild (447801) | about 11 years ago | (#8118270)

"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.

More importantly (-1, Offtopic)

scumbucket (680352) | about 11 years ago | (#8091940)

Vote for the new Krispy Kreme doughnuts!

Krispy Kreme [krispykreme.com]

Physics Problem (3, Informative)

WyerByter (727074) | about 11 years ago | (#8091994)

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.

Re:Physics Problem (1)

a whoabot (706122) | about 11 years ago | (#8092085)

Volume a large factor of course, but it's extremely complex. All sorts of things like high-frequency "presence" and attack speeds, etc. all affect where your brain places sounds in the spatial field. You can get "surround sound" effects with regular stereo headphones and regular stereo recordings too. A lot of ambient artists try to play with creating surround sound in stereo. And of course, any good engineer will talk about where things go in "the field", and they are referring to more than simple panning.

Re:Physics Problem (3, Interesting)

pbox (146337) | about 11 years ago | (#8092134)

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.

No it is not. Strange but true. You can always tell the direction (not just left-right but any degree in 3 dimension) where sounds come from (true only for tone above 100Hz or so). Therefore your ears/brain can somehow decipher the minite differences in sounds arriving to your ears.

However, back to the topic. You have 2 ears, therefore 2 speakers are enough to create a complete 3D soundscape. The 5.1 headphones are pure gimmick. You are better off spending some money on a decent pair of 2 speaker headphones, like AKG/Grado and my personal favorite, Sennheiser. If you like music, you are much better off spending $500 on a pair of headphones, than spending the same on 5.1 speakers.

There are some (classical) recordings out there that are done using a fake head, with mic in place of the eardrums. When using in-ear-canal headphones (think Shure / ER) you are placed in the sound environment exactly like where that head was. I belive it is called aural recording, but please post reply if you have correct info.

BTW, comp buffs, EAX by Creative is a model, which creates the 3D sound enviroment. It is a model on how our ears work and you can think of it as a 3D modeling, where you specify the 3D coordinates and the enclosing space (and types of walls), and the system outputs a L/R (or 5.1) signal which tries (with various degree of success) to place it in the right spot.

Re:Physics Problem (2, Informative)

Jerf (17166) | about 11 years ago | (#8092302)

However, back to the topic. You have 2 ears, therefore 2 speakers are enough to create a complete 3D soundscape. The 5.1 headphones are pure gimmick.

The 5.1 headphones would be pure gimmick, if we had been able to work out the sound transformations for convincing the brain a sound is coming from a given direction.

AFAIK, there has been progress in the field but it has hit a wall, and all the demos I've ever heard impart a very synthetic characteristic to the sound vs. the original source. (And I'm not speaking as an "audiophile"; the degradation in sound quality is clearly audible to me.)

The headphones can off-load these computations that are so freakishly complex we still can't do them onto reality itself, since "reality" remains better then any algorithm we've put together yet and doesn't sound synthetic.

Now, I've never used these or even heard of these, but I can easily believe that they are more then a gimmick at our current levels of understanding of sound spatialization. Nor would I expect two-speaker setups (headphones or otherwise) to match these any time in the forseeable future.

There are some (classical) recordings out there that are done using a fake head, with mic in place of the eardrums.

This goes to prove my point. Normally "preprocessing" sound before it gets to production is an anathema to a sound engineer; there's virtually nothing you can do to improve the sound while recording it, except record it with higher fidelity. "Aural recording" (if that's the name) is an exception, because you can't add that in post-processing, no matter what inputs you provide yourself. If it was something that could be added in post-processing, the sound engineers would insist on doing so to maintain maximal control over the sound.

Re:Physics Problem (3, Informative)

pbox (146337) | about 11 years ago | (#8092404)

Now, I've never used these or even heard of these, but I can easily believe that they are more then a gimmick at our current levels of understanding of sound spatialization. Nor would I expect two-speaker setups (headphones or otherwise) to match these any time in the forseeable future.

I agree.

So to summarize all this:

1. If the recording is mode with the fake-head, it is best to use 2.0 headphones / in-ear-canal or otherwise.
2. Rest of stereo audio sources are best with a 2.0 headphones
3. Computer generated sounds (especially FPS) best with 5.1 headphones (no or less calc involved)
4. DVD-Audio, SACD 5.1 sources are best with 5.1 headphones, IF are not remastered from a stereo source, but rather are recorded with 5 mono microphones.

Does anyone can improve / extend on above, please post.

Re:Physics Problem (1)

Jerf (17166) | about 11 years ago | (#8092897)

Sounds good.

So this is more then just a graceful "I'm not trying to be antagonistic" post ;-), I'd point out to people that really good 2.0 headphones are actually pretty easy to come by if you can get earbuds. As I write I'm listening to a Mozart clarinet concerto through my Sony MDR-W08 headphones [dealtime.com] , which are dirt-cheap as headphones come but nearly match the quality of my $100 studio-style headphones I bought for my synthesizor-based music composition. I don't know that you can get MDR-W08s right now (doubtful), but similarly good earbuds abound. Just make sure you get earbuds that fit into your ear; I accidentally got a pair once that seem designed for ears with holes about twice the size of the ones I own, and I'm a 6'4" guy (just shy of 2 meters for you metric folk).

My theory is that those little piezo-electric speakers are pretty good, but you need to get them close to the ear; once you do that, you've basically won the battle. The expensive headphones then concentrate on keeping other noises out. (This is not entirely true but seems a very good approximation.) You can get good sound from headphones with the speakers further out, but the highs and lows both seem to rapidly dissipate and it takes a lot more balancing work.

I'm not an "audiophile" per se, but I do appreciate the way these headphones don't suck the life out of music.

Re:Physics Problem (2, Informative)

Reducer2001 (197985) | about 11 years ago | (#8092554)

Nice info in parent post. The recording technique is called binaural [binaural.com] recording.

Re:Physics Problem (1)

Bob MacSlack (623914) | about 11 years ago | (#8093302)

Well, if you're an audiophile looking for the best headphones out there, the 5.1 are definitely not it. However, if you want them to play games or watch movies with 5.1 sound, they're definitely preferable. My friend has a pair, everyone thinks he cheats now :)

Mono audio with placement sweep (1)

Simonetta (207550) | about 11 years ago | (#8102225)

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.

Re:Physics Problem (4, Interesting)

Otter (3800) | about 11 years ago | (#8092175)

There was a famous neuroethology experiment with barn owls. They have asymmetrical ruffs on their ears, one pointing up and one down. Sounds have a different volume in each ear depending on the altitude of the source.

But, it was also showed (by putting headphones on them, playing a mouse sound and watching how their heads moved) that they use volume to determine altitude and time offset to determine bearing. So it's definitely possible -- although I have no idea what system human perception uses for the same problem.

Re:Physics Problem (1)

jpop32 (596022) | about 11 years ago | (#8111987)

But, it was also showed (by putting headphones on them, playing a mouse sound and watching how their heads moved)

Ok, so where's the obligatory link to the owl with the headphones?

Re:Physics Problem (0)

Anonymous Coward | about 11 years ago | (#8138841)

That would be, "But, it was also shown..."

Re:Physics Problem (4, Insightful)

mleczko (628758) | about 11 years ago | (#8092869)

Well, actually, you only need two channels for surround sound. There are quite a few factors to define where a sound source is located. As far as the horizontal plane is concerned, the location is determined by two factors. First the time difference between the arrival at the ears is taken into account (makes for a astonishigly small time scale, especially with higher frequencies, but the brain can handle it). Then, the volume difference is evaluated: If a sound source is to your left, the signal is louder in your left ear then in your right. As far as vertical position is concerned, the form of your outer ear is relevant. Dependent on the position of the sound source, different frequency bands are attenuated or amplified. These are the so called HRTFs (Head Related Transfer Functions). Using this information, you can filter your sound sources with the according transfer functions and get a really realistic result. I once was able to try out such a system as part of a course here at university. It simulated 5 sound sources in a room and there was a head-tracker mounted on the headphones. So if you turned your head left, the drums would become louder. Pretty cool stuff! :-)

Re:Physics Problem (1)

nathanh (1214) | about 11 years ago | (#8097334)

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.

That's assuming that the brain measures the timing delays.

I recall reading somewhere - I forget where - that the shape of the cochlea helps determine frequency. Higher frequencies tickle the hairs further along the cochlea.

I could easily see similar tricks being done "in hardware" to get accurate measures of timing delays rather than relying on the brain's processing power.

Re:Physics Problem (0)

Anonymous Coward | about 11 years ago | (#8098011)

nitpicking; the delay is less than a millisecond. 3 orders of magnitude difference ;-). also, what is interesting is the phase difference of the sound entering the ears. that is detected by the brain. imagine a sustained tone from a source moving around in space...

Well calculated delay (4, Informative)

forsetti (158019) | about 11 years ago | (#8092036)

The Headphones are "smart" enough to create an appropriate delay, per channel, to cause that spatial effect you refer to.

Read CPU magazine for a review (4, Informative)

phoenix_rizzen (256998) | about 11 years ago | (#8092060)

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).

Better quality options? (1)

GCP (122438) | about 11 years ago | (#8095100)

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.)

Like false 3-channel surround sound (1)

eclectric (528520) | about 11 years ago | (#8092108)

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 has these (2, Interesting)

gyratedotorg (545872) | about 11 years ago | (#8092110)

a friend of mine has these. i havent tried them yet, but he's been raving about them.

Not to be snarky: (5, Informative)

attaboy (689931) | about 11 years ago | (#8092139)

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...

www.rbmods.com [rbmods.com]

www.hardextreme.org [hardextreme.org]

http://www.fastlanehw.com [fastlanehw.com]

www.itpro.no [fastlanehw.com]

www.hardware-testdk.com [hardware-testdk.com]

ohls-place.com [ohls-place.com]

Re:Not to be snarky: (0)

Anonymous Coward | about 11 years ago | (#8100098)

I fucking hate it when people say things like
"Not to be snarky" and then go off being the thing they just mentioned.
Its kind of like the old
I don't want to sound rude (then goes on to say something rude)...
It just fucking bugs me. I love reading comments for the info but I wish some of you would lose the
***FLAME ON*** mode that you are stuck in from early 90's usenet wars of words.

So, in conclusion, +5 informative, -1 smarmy attitude. And that solves the mystery of the missing ring.

Re:Not to be snarky: (1)

buck_wild (447801) | about 11 years ago | (#8107840)

I'd be interested in hearing where you've seen them listed for $40. The lowest price I've seen thus far is ~$55.

Re:Not to be snarky: (1)

attaboy (689931) | about 11 years ago | (#8116031)

Apparently they were $39.99 on NewEgg, but are now listed at $54.99.

Two Ears (2, Funny)

sabNetwork (416076) | about 11 years ago | (#8092141)

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.


Re:Two Ears (1)

slaker (53818) | about 11 years ago | (#8096815)

I know some people aren't into the multichannel recording thing but just to amplify: 5.1 channel audio recordings are available, even for those of you who have nothing more than a decent component CD player.

So go find yourself a DTS CD (you'll need a digital output to something with a DTS decoder, but that's still not really a big deal), or a multichannel SACD or DVDAudio, and its plain-old stereo CD equivalent.

For an example, Telarc's recent issue "Rainbow Body". Available on Audio CD and on SACD (note: if you aren't into classical music, I believe several of "The Police" albums are available in all four formats: CD, DTS CD, SACD and DVDAudio).

Listen to it in unmatrixed stereo from the CD recording. Telarc is an audiophile label, and it sounds good with my two ears.

Then try the same CD in a matrixed surround mode (Neo:6 or Dolby ProLogic II). It's a little gimmicky; most of your sound will come from your center and the surround channels will basically echo the front L/R channel. I can discern some directionality, even with my standard-issue two ears.

Then try the mulitchannel SACD version of the same recording: Now you have an even (if your speakers are properly placed and timbre-matched) pan from left to center to right, essentially matching the seating of the orchestra, and sparsely-used surrounds reserved for the reverberations of brass and percussion, much closer to the way someone in the audience might've heard it.

I can tell the difference between all three. This isn't a "golden ears" thing. If you actually listen to multichannel recordings for any length of time, you'll be able to tell, too.

Re:Two Ears (1)

acidrain69 (632468) | about 11 years ago | (#8102497)

IANAAP (Audio Phile)

It seems to me that there is more than what you HEAR that determines direction. I wonder if your body can sense the sound waves to help determine direction.

If what you say is true, then how do you determine if a sound is coming from in front or behind you? If the direction-dtermination is based on the time difference between the 2 ears, there are an infinite number of points that represent the true source of the sound, represented by a circle.

If this is hard to understand in words, imagine holding a hula-hoop in the air off directly to your right, somewhere outside of your vision. That hula hoop represent all the points where the distance between the hoop and both ears is the same. Now different positions in space can be represented by different sized hulahoops, located at different distanced from the ear.

How can you tell where on the hula hoop a sound-making object is? Sound waves. Visual cues. How do you tell if something is behind you and coming from above or below? The distance to your ears will be the same either way. Having multiple speakers allows you to add a directional component instead of extrapolate one from a 2 receiver source (your ears).

Sony alternative (2, Interesting)

HeroicAutobot (171588) | about 11 years ago | (#8092188)

Sony also has the much more expensive MDR-DS5100 [sonystyle.com] and the still even more expensive MDR-DS8000 [sonystyle.com] .

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.)

Re:Sony alternative (0)

Anonymous Coward | about 11 years ago | (#8122050)

try head-fi.org, I'm sure somehwere there can fill you in on the sonys (even though most of the folks over there are audiophile sorts, there's always a mixed bag of reviews and feedback)

You know what? (4, Insightful)

Lord Bitman (95493) | about 11 years ago | (#8092197)

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?

Editors need to stop accepting stories with these bullshits tacked on. If you want to make a completely uninformed comment, post a comment after[if] the article is accepted.

Re:You know what? (1)

WyerByter (727074) | about 11 years ago | (#8092454)

Where as part of the question was if, the other part of the question was how. And that answer the engineers don't usually put on their websites, because the marketing guys don't let them anywhere near it.

And if you think that HOW is a BS question, why are you here?

Re:You know what? (1)

Lord Bitman (95493) | about 11 years ago | (#8093114)

I'm not saying the question has no merit whatsoever, but too many articles are of the form:
[News Item/Question] [Completely Fucking Stupid Comment/Extra Question which has been "tacked on" and has no redeeming value whatsoever]

They're editors. Would it kill them to edit every now and then?

Re:You know what? (0)

Anonymous Coward | about 11 years ago | (#8093003)

Ah, but the people who write the marketing boilerplate do NOT do this for a living.

Re:You know what? (3, Insightful)

Elwood P Dowd (16933) | about 11 years ago | (#8093211)

Ah, yes, the engineers may have thought about it, decided that it would be too expensive to implement, and then done something that doesn't work well but only costs $40 rather than $600 for the competing Sony product.

So, marketting or otherwise, his question is worthwhile. His question can be answered by a myriad of reviews available on the subject, but that's not what you seem to be talking about.

Easy (2, Insightful)

wishus (174405) | about 11 years ago | (#8092198)

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.

Part of Patriot Act Ruled Unconstitutional (-1, Offtopic)

Anonymous Coward | about 11 years ago | (#8092205)

Part of Patriot Act Ruled Unconstitutional

Jan 26, 2:52 PM (ET)


LOS ANGELES (AP) - A federal judge has declared unconstitutional a portion of the USA Patriot Act that bars giving expert advice or assistance to groups designated foreign terrorist organizations.

The ruling marks the first court decision to declare a part of the post-Sept. 11 anti-terrorism statute unconstitutional, said David Cole, a Georgetown University law professor who argued the case on behalf of the Humanitarian Law Project.

In a ruling handed down late Friday and made available Monday, U.S. District Judge Audrey Collins said the ban on providing "expert advice or assistance" is impermissibly vague, in violation of the First and Fifth Amendments.

John Tyler, the Justice Department attorney who argued the case, had no comment and referred calls to the department press office in Washington. A message left there was not immediately returned.

The case before the court involved five groups and two U.S. citizens seeking to provide support for lawful, nonviolent activities on behalf of Kurdish refugees in Turkey.

The Humanitarian Law Project, which brought the lawsuit, said the plaintiffs were threatened with 15 years in prison if they advised groups on seeking a peaceful resolution of the Kurds' campaign for self-determination in Turkey.

The judge's ruling said the law, as written, does not differentiate between impermissible advice on violence and encouraging the use of peaceful, nonviolent means to achieve goals.

"The USA Patriot Act places no limitation on the type of expert advice and assistance which is prohibited and instead bans the provision of all expert advice and assistance regardless of its nature," the judge said.

Cole declared the ruling "a victory for everyone who believes the war on terrorism ought to be fought consistent with constitutional principles."

Spatialization can work with headphones (4, Interesting)

esm (54188) | about 11 years ago | (#8092236)

Sorry, I have no experience with these headphones. But: about 10 years ago, I volunteered as a test subject for some experiments done at NASA Ames (Mountain View, CA, USA). One of them was for a device called the Convolvotron [o-art.org] . It's a thingy (sorry for the technical term) which takes multiple sound sources and "localizes" each one so it sounds like it's coming from a different place. It worked incredibly well with only two speakers. The big problem was distinguishing between straight-in-front and straight-behind. With headphones and human ears, I suspect that's just a darn difficult problem. But side-front, side, and side-rear were very easy to differentiate.

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 [google.com] for "Convolvotron". Enjoy.

Re:Spatialization can work with headphones (1)

ziggles (246540) | about 11 years ago | (#8093454)

I have no idea if it uses similar technology, but I find the Dolby Headphone technology found in some dvd players (WinDVD and PowerDVD for Windows most notably) works to similar effect.

Re:Spatialization can work with headphones (1)

Nucleon500 (628631) | about 11 years ago | (#8093802)

Two things would interest me greatly. One, to hear those tapes. Two, I wonder what effect various types of lossy audio compression would have on the effect.

Re:Spatialization can work with headphones (2, Insightful)

jhoffoss (73895) | about 11 years ago | (#8097103)

Actually, the straight in front and straight behind thing is related more to the human ear/brain/central sound processing unit/whatever. If a sound takes exactly or almost exactly the same amount of time to travel to both ears, there's no way for the brain to determine a direction without echoes or reverberation or something.

If you close your eyes and have someone snap their fingers directly behind or directly above your head, you probably will not be able to determine quite where it's coming from.

Note: this info is based on one intro course I took my freshman year five years ago, and I'm not a doctor/medical student or anything, so I may be off...

Pope hosts break-dance party (-1, Offtopic)

Anonymous Coward | about 11 years ago | (#8092244)

Break-Dancers Perform For The Pope, Get His Blessing

VATICAN CITY -- In an unusual spectacle at the Vatican, Pope John Paul II presided Sunday over a performance of break-dancers who leaped, flipped and spun their bodies to beats from a tinny boom box.

The 83-year-old pontiff seemed to approve, waving his hand after each dancer completed a move, then applauding for the entire group. He watched the performance from a raised throne.

"For this creative hard work I bless you from my heart," he said.

During the show, one dancer -- part of a Polish group that helps poor and marginalized youths -- planted his head on the inlaid marble floor of the Vatican hall and spun to loud applause from his group and from Vatican officials. Another performer flung his body around in a series of spins and handstands.

"Artistic talent is a gift from God and whoever discovers it in himself has a certain obligation: to know that he cannot waste this talent, but must develop it," John Paul said.

Earlier Sunday, members of an Italian Catholic youth organization enthusiastically cheered the pope's weekly remarks in St. Peter's Square. A few were invited into his papal apartment and helped him release doves from his window.

The pope, who suffers numerous ailments but appeared relatively strong Sunday, called out to the other children cheering below his window.

"I love you all. I love you very much," he said.

Copyright 2004 by The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

cues (4, Interesting)

ballpoint (192660) | about 11 years ago | (#8092254)

Left-right stereo has been here a long time and it works wonders with headphones. No doubt about that.

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 /. 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.

(*) 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.

Hearing (2, Interesting)

DarkDust (239124) | about 11 years ago | (#8092260)

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.

Sennheiser .. but still no subwoofer (3, Insightful)

dk.r*nger (460754) | about 11 years ago | (#8092285)

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.

Re:Sennheiser .. but still no subwoofer (1)

Babbster (107076) | about 11 years ago | (#8094005)

Unfortunately, half of your neighbor's READING experience is probably feeling your surround experience in their stomach.

Re:Sennheiser .. but still no subwoofer (0)

Anonymous Coward | about 11 years ago | (#8097504)

I don't think you 'get' it - the Sennheiser headphones are meant for recording, mixing and mastering -- which means they need to be *completely* uncoloured (ie - no bass boost) as much as physically possible.

3d sound with 2-speakers (2, Interesting)

TrebleJunkie (208060) | about 11 years ago | (#8092346)

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.

Re:3d sound with 2-speakers (2, Informative)

mnbjhguyt (449178) | about 11 years ago | (#8093553)

this kind of effect has been around for quite some time (best known example is the beginning of the final cut album from pink floyd) (hint: google for holophonia or holophonics)

iirc it's actually very simple, the sounds were recorded using a dummy head with two mikes where the ears would have been

Something I would like to point out (2, Insightful)

ewhenn (647989) | about 11 years ago | (#8092385)

In 5.1 the ".1" is a subwoofer. These headphones can't possibly be 5.1

Re:Something I would like to point out (0)

Anonymous Coward | about 11 years ago | (#8092834)

No the second number is the non-discrete channel.

Re:Something I would like to point out (0)

Anonymous Coward | about 11 years ago | (#8092977)

...which happens to be the subwoofer

Re:Something I would like to point out (1)

duplicate-nickname (87112) | about 11 years ago | (#8093612)

...which happens to be the low frequency effects channel that can be played by a subwoofer or any other speaker than can handle the frequency range.

If I had 4 subwoofers, does that mean I have a 5.4 system? No.

Re:Something I would like to point out (1)

buck_wild (447801) | about 11 years ago | (#8107985)

"or any other speaker than can handle the frequency range"

The original poster's point remains intact, to a degree, as does yours.

Re:Something I would like to point out (1)

NanoGator (522640) | about 11 years ago | (#8128906)

With some duct tape, some excedrin, and an extension cord, bet you could make it work.

No. (2, Interesting)

3-State Bit (225583) | about 11 years ago | (#8092541)

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 [google.com] and your ears are about a foot apart.

That means there is a difference of 895.706603 microseconds [google.com] between when the first ear would hear the sound and when the second one would.

This is 1/1116th [google.com] 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 [everything2.com] a couple of orders of magnitude slower than this, and moreover the theoretical maximum a single neuron can tick is 2000 hertz [mit.edu] , 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.

Yes, was Re:No. (1)

12dec0de (26853) | about 11 years ago | (#8093250)

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

Re:No. (3, Insightful)

Anonymous Cow herd (2036) | about 11 years ago | (#8093253)

Your basic mistake is imagining that human sensory input is clock driven rather than signal driven. Your auditory cortex isn't out there "polling" your ears to see if you're hearing anything, rather, the sensors in the ear signal the cortex once a sound (input event) is detected. Also, while the number of points that match your two 'ear judged' distances are infinite (but for all practical purposes, it's finite, this is a variation on Xeno's paradox) your ears are directional, due to their shape (this is also how you can tell difference between sounds in front and behind)

Re:No. (3, Informative)

Frans Faase (648933) | about 11 years ago | (#8098239)

This argument is completely of the mark. The brains does contain specialized areas for detecting the delay. For low tones the spikes produced by the detecting hair cell, match the wave front. These are than transported to an area in the brain where there is a line of cells where the signals from both ears are at opposite ends. The cells where the signals arrive at the same time (depending on the delay caused by the spike to travel through that cell in the line) produce the strongest response and determine the direction from which the sound originates.

Re:No. (0)

Anonymous Coward | about 11 years ago | (#8108111)

I wish there were a "-1, Sorely Mistaken" mod. Your statement, "Knowing nothing about human hearing we can almost rule out this conjecture." in fact is the crux of the problem.

The human brain does, in fact, use timing information to generate localization information. It also uses loudness information and equalization information. Your ear is shaped as weird as it is because it's a mechanical filter whose response varies with angle and azimuth.

The timing information, delay, can also be treated as phase shift. Try this - generate a tone, and a delayed version of that tone. You can try this with program audio material as well, preferably something with some crisp cymbals. Play the original sound in one ear and the delayed one in the other ear, using a pair of sealed headphones. No sound from the left 'phone will reach the right ear, and vice versa - this rules out any localization due to volume differencing. Vary the delay between 100 microseconds and 2 milliseconds. Report back here on what you heard. Hint - it's called a flanger.

I'm curious - why would you spend so much time debunking a subject you are totally clueless about?

Re:No. (0)

Anonymous Coward | about 11 years ago | (#8118687)

I wish I could take my post back as sorely mistaken! But at least I learned something... (from each of the replies.)

Cool. (1)

gmaestro (316742) | about 11 years ago | (#8092750)

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'.

Congratulations (1)

ianscot (591483) | about 11 years ago | (#8127140)

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.

Dolby Headphone Technology? (1)

Pilferer (311795) | about 11 years ago | (#8094578)

Not quite the same thing, but has anyone had any experience with this [dolby.com] ? 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...

Your old headphone is sufficient (1)

francium de neobie (590783) | about 11 years ago | (#8096613)

I'm sure many of these geeks here have used PowerDVD or WinDVD here. There has long been a technology to simulate Dolby 5.1 (YES! with the .1 even!) with 2 sided headphones. And that's the little Dolby Headphone thing in your PowerDVD settings. (I think somebody else has posted this URL too, but anyway...) http://www.dolby.com/dolbyheadphone/ More detailed description here http://www.dolby.com/dolbyheadphone/DH_Story.html The human ears takes a lot more cues than simple difference in amplitude and timing of ONE sound souce, in constructing a 3D model in your brain. In fact, if only these simple differences are taken, it can only simulate a 2D environment. You gotta be cheating yourself if you think you're hearing in 2D. One of the aspects of sound that the human brain is known to exploit is the fact that it reflects off surfaces - a sound source would reflect off a wall, the floor, your outer ear, your head and produce secondary wavefronts. These wavefronts arrive at slightly different timing and highly different amplitudes in the ear. Your brain takes in these secondary wavefronts as extra cues in calculating the possible positions of a sound source. In fact, it was determined the shape of your ears and your head affects spatial hearing. From the Dolby website:
it was found that they varied widely due to differences in the distance between each person's ears, and in the shapes of their ears and head.

I'd go for 5.2 (4, Funny)

cr@ckwhore (165454) | about 11 years ago | (#8096634)

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.

Re:I'd go for 5.2 (1)

.!.+(0.o)+.!. (671291) | about 11 years ago | (#8103038)

could I get some of what you're smokin?

I don't believe it's just the ears... (2, Interesting)

stvangel (638594) | about 11 years ago | (#8096923)

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.

For the smart-asses, the answer (4, Informative)

Tamor (604545) | about 11 years ago | (#8097495)

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.

And that's why... (1)

Tamor (604545) | about 11 years ago | (#8097875)

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.

Of course they do... (1)

JamesP (688957) | about 11 years ago | (#8098518)

if you have 5.1 ears...

Simplified Head Related Transfer Functions (0)

Richard Dansereau (19013) | about 11 years ago | (#8098704)

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.

a big letdown (1)

krumbs (115589) | about 11 years ago | (#8100333)

well, swayed by the hype and the claims, i picked up a pair of isound 5.1 home theatre headphones [enteriworld.com] . 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!
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