[X3D-Public] potential free audio formats for X3D - ogg and flac

Dave A dave at realmofconcepts.com
Fri May 10 14:24:58 PDT 2013

On 5/10/2013 12:49 PM, Michalis Kamburelis wrote:
>>> X3D working group: we should also consider improving the aural
>>> spatialization model in next year's X3D v3.4. 

Good point!

I think it's high time we look at incorporating phase, aka 
time-of-flight, into audio. Binaural or holographic sound is more a 
matter of the timing between when one of your ears hears a sound before 
the other, than of the loudness of that sound. With normal stereo 
'spatialization' the sound can't sound further apart than the two 
speakers you have (and multi-speaker systems are, IMHO a hack). But 
phase-correct stereo, the sound may even have about the same loudness in 
each ear, yet sound like it's coming from 'way over there' or 'up there' 
or 'back there'.

I'm pretty sure many hardwares support this, and even if not, today's 
processors can handle it. It's at least worth looking at. Even if the 
typical PC is not up to it today, it will be by the time a spec is 
agreed upon.

A simple first step would just be to delay the waveform based on the 
distance the audio source is from the current camera, +/- inter-ear 
distance, plus some attenuation for the more-distant ear. Not too 
different from stereo vision in concept.

Dave A.

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