Very clever people have been able to develop computer programs that can recreate physical, three-dimensional surround sound, using only a pair of headphones. While there are a fair few programs out there that achieve this (It is also as of 2016 an available option in 360 Youtube videos), the people at New Audio Technology in Germany have developed their product called The Spatial Sound Card, which uses their own proprietary sound spatialisation technology that - in my opinion - is the most realistic 3d surround sound recreation for headphones that I’ve heard.
You don’t need any special hardware to use it. Just open it up and enjoy convincing surround sound in your headphones! And it only costs $10!
The immediate applications are of course cinematic movies and also games, however the tantalising combination with virtual reality is something that I’m sure we’ll see as standard within the next ten or fifteen years.
» You can demo the product directly on their website here.
If you’d like a little clarification on what sound spatialisation is and therefore why this technology is so impressive, keep reading below.
Sound spatialisation is the science of placing sound around the listener in order to create a more immersive listening experience. This has for a long time been the way we listen to the audio in movie cinemas, the common format being 5.1 channel surround sound. This basically means six individual channels of audio, typically being output by six individual speakers (five surrounding us and one sub-woofer). Channel counts of surround sound systems can reach dizzying heights, particularly when we enter into the realm of Ambisonics, which simply put is the implementation of complex mathematical formulas to spatialise sound not just on the horizontal plane (like cinema 5.1/7.1/11.1/etc), but also on the vertical plane.
The basic premiss of all surround sound formats is that they try to recreate a natural listening environment, where by sounds are projected into our ears from different directions at different times and with varying harmonic content that is filtered and affected by the physical material in our environment - including our ears themselves. This is how we locate sound in space.
For example, if a sound is directly in front of us, it will enter into our ears at the same time, the outer ear helping by refracting sound into the inner ear. If a sound is directly behind us, it will also enter into our ears at the same time however this same sound will have its high frequencies filtered (in other words, the high frequencies are made quieter) by the skin and cartilage of our ears. This is one of the fundamental ways we determine sound being behind us and not in front. It is also why bass frequencies are omni-directional, because bass frequencies pass through most material without much loss in power.
So, in conclusion, what sound spatialisation software like The Spatial Sound Card essentially does, is mathematically process information from audio streams, manipulating and sculpting their sonic character to follow the natural behaviour of sound in space, and hence localising them in a virtual sonic space.