Dolby Atmos is the latest multichannel audio format; rather than mixing down to a fixed 5.1 or 7.1 master, an Atmos master carries spatial metadata that can be decoded and rendered to any array of loudspeakers, from a binaural mix for headphones to a 24.1.10 home theater setup. Windows and Xbox One both support Dolby Atmos support; Windows also has a native spatial post-processor called Windows Sonic.
> You only need two channels to provide complete spatial information through headphones if it's a binaural recording.
I don't really believe this, given the shape of the human ear and my own experience trying to reproduce 3d sound. Humans can judge direction and distance remarkably well up to a few dozen meters.
The whole point of binaural recording is to exploit the shape of the human ear to encode spatial information.
A binaural recording setup uses an artificial head with artificial ears, with the microphone capsules located where the eardrum would be. The microphones capture the phase and magnitude effects of the head and outer ear. Unless you have really weird ears or really bad headphones, the effect is extraordinarily lifelike.
It's also possible to process sounds digitally to create a binaural effect using convolution. Using a mathematical model of the ear and head (a head-related transfer function), you can position sounds in a 3D space around the listener. Many games offer HRTF audio and it provides remarkably accurate spatial information. HRTF audio is a key aspect of the immersiveness of VR experiences. It's possible to generate a unique HRTF based on your own anatomy, using either an audio capture from a microphone placed inside the ear or a 3D scan of the user's head.
I did a thing as a kid that basically proves it out.
I recorded my home, an afternoon with the family from the speakers that it would be played back from. After some fiddling with a pre amp to get the recording balanced well enough to play back, the effect was pretty effective.
I didn't expect it, but when that recording was played on that system and speakers, it was possible to sit in my room and basically hear the house! TV in the front room, dog walking around, doors closing.
Brought people in late at night to play it. Was spooky to hear midday sounds, and believe them. The illusion was that good.
Here’s the funny thing: humans can discern vertical positioning as well as horizontal positioning. Binaural recordings can’t reproduce that, since it’s highly dependent on the shape of our ears.
Yes, but the way our nervous system does this is by two mechanisms:
1) The inter-aural time difference. Sound takes time to travel, so any sound coming from left of the head will arrive at the left ear sooner than the right ear.
2) The head-related transfer function. The shape and auditory characteristics of the head and ear canal change the sound slightly depending on the frequency and the direction of the incoming sound. Since this direction is different for the two ears, your auditory system can compare the 'shape' of the sound it gets from each ear and use that to position the sound in space.
The inter-aural time difference is, by far, the more effective of the two, but it only gives horizontal bearing. It also can't give 'in front' or 'behind'. The head-related transfer function can give both horizontal and vertical bearing, but it's not that accurate. Together, these explain why humans are far more accurate at localizing sounds horizontally than vertically.
Binaural recordings try to capture both of these mechanisms through stereo recording with a mock head. That's why listening to a binaural recording gives you the feeling of sounds coming from a point in space, because it's replicating the same experience you'd get from actually being in that space.
I have a friend into binaural recording, he has a rig shaped liked a head with 3d-printed ears. He wanders around the woods recording birdsongs with it. I would imagine that provides a fair degree of verisimilitude.
https://www.youtube.com/watch?v=Yd5i7TlpzCk
Dolby Atmos is the latest multichannel audio format; rather than mixing down to a fixed 5.1 or 7.1 master, an Atmos master carries spatial metadata that can be decoded and rendered to any array of loudspeakers, from a binaural mix for headphones to a 24.1.10 home theater setup. Windows and Xbox One both support Dolby Atmos support; Windows also has a native spatial post-processor called Windows Sonic.
https://www.dolby.com/us/en/professional/content-creation/do...
https://msdn.microsoft.com/en-us/library/windows/desktop/mt8...