what is Binaural?

Binaural audio can be simply explained as 3D sound. That is to say that when something is recorded binaurally, its playback results in the precise recreation of those sounds as we would hear them in our own ears - the acoustics, volume and location on a 360 degree axis around our head.

This is because the process uses a model (or sometimes real) human head to record the sound into two microphones, positioned in the center of the ears. With the microphones positioned this way, a source of sound coming from the left will hit the left microphone moments before the right one. The resulting delay between the two is how the brain analyses the position of things we hear in the real world. Close your eyes and listen right now, and you’ll probably realise you’re already doing it.

In addition to this basic delay there are also changes in amplitude and volume, caused by what is known as “head shadow”. When sounds are dulled while passing through the back of the head or ear lobes we are able to identify which region of the head they must be passing through. The combination of these factors creates an immersive audio experience, giving your head an absolute position within the world being recorded.

This technology isn’t new, it’s been around since the late 1800s. So why haven’t you heard of it before, and why isn’t everything recorded binaurally? The reason it never took off is that it only works if the listener is wearing headphones, and at the time this was seen as a limitation - it wouldn’t work for radio. Instead of going down the radio route, early experimenters went on to create stereo technologies like the Dolby Surround Sound system, which still uses the dual outputs, but on a larger open speaker setup. And while there have been occasional experiments from various audio producers such as the BBC and music producers including Kate Bush and Pearl Jam, the technology has remained on the fringes.

Now, with the huge increase in headphone usage, the issue seems to be becoming redundant. 

Could binaural finally take center stage in the world of audio drama? We think so.