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?"

Comments

Ask Slashdot? What about Ask the Manufacturer?

[wolf-]

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.

You know what?

[Lord Bitman]

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?

[Elwood P Dowd]

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

[wishus]

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.

Sennheiser .. but still no subwoofer

[dk.r*nger]

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.

Something I would like to point out

[ewhenn]

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

Re:Physics Problem

[mleczko]

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:No.

[Anonymous Cow herd]

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:Spatialization can work with headphones

[jhoffoss]

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...