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How Binaural Recordings Simulate 3D Sound in Headphones

By Bobby Schweizer

You have to listen these binaural recordings!

Grab a pair of headphones, open up the Virtual Barbershop, close your eyes, and prepare to be impressed. It's no fancy piece of new technology. It's two microphones located next to the left and right outer ear of a human head weaved together using a special algorithm. The result is a binaural recording that sounds three-dimensional.  

Starkey Labs for use with hearing aids, took the century old method of binaural recording and digitally processed it to simulate the brain's reception of sound through the physical form of the ear. Let's look at how it works and the effects it can produce.  
 

 
dummy heads that approximate the average geometry of the human head and ears. It takes into account the minuscule differences between when our left and right ears hear a sound and even the effect of our skin on sound waves.  
 
Because binaural recordings depend on tapping directly into the human brain, the audio source must be transmitted directly into the corresponding ear. Take off your headphones and the Virtual Barbershop sounds like nothing more than a recording that moves back and forth between two speakers. The same effect can be achieved with special loudspeakers that cancel the cross-talk of the two sources. Even your headphones don't precisely reproduce the recorded sound because of the way they're engineered, but they are close enough to get the desired effect.  
 
Despite its long history, binaural recordings have not gained much traction, having generally being viewed as an experimental novelty. Notable binaural media include Pearl Jam's Binaural album, a Monsters Inc. DVD extra with, and iPhone games Zen Bound and Papa Sangre. Walt Disney World's Hollywood Studios features an attraction called Sounds Dangerous which puts on a binaural show starring Drew Carey.  
 
But there are plenty of binaural recordings on the net that you can check out right now. The Virtual Barber has compiled some particularly good ones, Javox put together their own top ten, and Listen With Your Own Ears has some excellent examples from YouTube. The coolest of these is the Arkamys Holographic Ball Experiment which puts you in the shoes of a man looking into a mirror listening to the sounds behind you.  
  
  
Given how easy it is to make one of these recordings, it will be interesting to see if the binaural effect ever takes off in popular media. Mobile devices, as personal media players that use headphones, seem like the perfect outlet for creative implementations. But it will ultimately depend on how people view it—immersive addition or novelty effect.