Other Uses of Binaural
A current emerging use for binaural audio is within Virtual Reality (VR). Filmmaker, George Lucas, once stated how audio makes up 50% of a video experience (Bible, 2016). VR must provide an immersive experience for the user, therefore binaural audio can be used to enhance this. ‘VR audio gives us a number of powerful tools to achieve this, like being able to direct the viewer’s attention, enhance user feedback, and drive emotions.’ (Bible, 2016).
There is, however, one issue with binaural in VR. A system had to be developed to allow binaural sound to be captured in 360 degrees. If a user turns their head while using VR, the sound should also change to copy the way their head is looking (Lalwani, 2015). Chris Milk, a popular video director, explains the issue.
"If we were going to let you look in every direction, a one-directional sound source would not work," he says. "You would look behind but you would still hear as if you were looking in front of you. So we needed something that would dynamically change based on where you were looking in the visual." (Lalwani, 2015).
He developed an omni-directional binaural dummy head that is fitted with eight ears, each facing at right angles to capture audio from 4 perspectives, Figure 27. Specially designed software is then used to feed the correct signal from each set of ears to the VR user (Lalwani, 2015).
Head motion tracking is also used to be able to know where the user is facing. This has also been used in several mobile apps that have used binaural audio. A head tracking device can be fitted to headphones to enable this, allowing the user to interact with the audio, facing different directions to adjust the sound (Pike, 2013).
Figure 27 Omni-directional Binaural head
Binaural audio has not yet had a large impact on VR and is not largely used within it. Often, audio is considered less important than visuals when creating content. Lead engineer at VR developer Jaunt, Adam Somers, states ‘So much work goes into visual elements, whether it’s a game or a film, that sometimes audio is an afterthought’ (Lalwani, 2015).