3D Audio From Ordinary Speakers (Video Demo) | Hacker News Reader

3D Audio From Ordinary Speakers (Video Demo)

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13 pointsshawndumas19 comments

Wouldn't his technique require the listener to be sitting still and have his ears in exact specified locations? Not very practical then if that's the case. I guess the system can include some sort of (visual) ear recognition and tracking logic and adjust the cross-talk filter respectively, but (a) that's pretty far off (b) still won't work for more than one listener.

Moreover...

> The filter is designed to work with loudspeakers - not headphones

Because regular stereo in headphones already has no cross-talk, so it is naturally 3D. And this leads to the trivial 3D stereo solution (if one really wants it) - just put the headphones on.

I think the most useful application of this technology(except entertainment) would be conference calls. Even with a polycom conference phone, you still have to concentrate to follow the conversation. It's even worse when people don't wait their turn to talk...

If someone can include this technology in an unobtrusive way in Skype, there's a Nobel prize waiting for them...

In the late 80s-early 90s, 3D sound with stereo speakers was all the rage : Q-Sound, Roland RSS... there were several competing processing systems. Sting's "The Soul Cages" did use Q-Sound quite heavily, for anyone interested (edit: correct Sting album reference).

Downloaded the 720p version (it has 128kbps AAC) to play back with a better decoder than flash and it does seem to work - I'd like to hear more demos though.

On rare occasion the old stereo-wide feature on my TV can make a sound seem like it occurred behind me (with just 2 cheap speakers) now that's something they need to research and reproduce - this demo had nothing from behind me.

Great stuff. Without correct speaker positioning and well-matching HRTFs for each listener, I feel that this won't fly.

Btw: I'm thinking about creating a 3D audio game where the HRTF model is constantly refined for the player while he is playing. Does anybody know whether there has already been work done in this direction, either academically or in the indie game world?

http://connect.creativelabs.com/openal/default.aspx

Is Creative sponsoring this? I thought they killed A3D in favor of the (inferior) EAX after they bought Aureal.

Yes, Papa Sangre uses real-time binaural 3D sound, www.papasangre.com. I'm not aware of any other real-time binaural solutions. I'd like to know too if there's more. OpenAL and other out of box 3D sound engines are stereo, not binaural.

Yes, I've tried Papa Sangre. Unfortunately, it uses a general purpose HRTF, which limits the immersion potential.

What do you mean by general purpose HRTF? Do you mean that the HRTF should match the player's head somehow? I haven't played Papa Sangre so I don't really know how well it works.

Yes. A custom HRTF makes all the difference between "hey this is kinda cool" and "holy guacamole I can locate everything down to a tee".

Sorry for the late responses. Yes, I'd imagine it should work better. In my case I don't tend to hear frontal direction in most binaural recordings. How would you create such a custom HRTF? Measuring somehow or should it be manually calibrated? Seems like a pretty interesting problem, I might do some experiments with this some day.

Exactly, many people cannot differentiate front/back and up/down with general purpose HRTF, something that is much better with a custom HRTF.

For basic experiments, put 2 small microphones into your ear canals, hit record, then go for a walk. The result will blow you away :-)

To record your custom HRTF, get an anechoic chamber, put 2 small microphones into your ear canals, then record impulse responses from all directions. Not quite as simple.

Good luck! Post your results here!

This effect didn't work so well for me. 3D Audio (from stereo source) has been experimented with for years. I have heard most of them. The most believable reproduction I have heard is here, http://www.nucleusdevelopment.com/downloads/4-654%20matches.... . It should be heard with high quality headphones. You can hear from the short demo, the replay has complete 360 degree reproductive control. You can almost feel the blowdryer in your ear, http://www.nucleusdevelopment.com/downloads/4-654%20blowdry.... .

Both links are dead.

Sorry. Fixed.

I've just watched the video on my laptop and this 3D audio actually works! It's amazing! I'd really like to see more demos.

My guess is that his "filter" is phase cancellation, which is nothing new.

As he explains in the video, phase cancellation doesn't work well when you stick your head into it. The head-related transfer function interacts with it in complex ways, so it's not easy to keep audio fidelity and spatial information at the same time. http://en.wikipedia.org/wiki/Head-related_transfer_function

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