Exploring New Sonic Worlds: Sound for Virtual Reality

Hi Varun, where does virtual reality currently stand in terms of audio?

It is still early days, in terms of technology, workflow and design principles. While the art of designing sound would still be similar (as would the art of image composition, storytelling, etc), virtual reality as a medium needs exploration. In the past two years we have seen some incredible work on the visual front, with thousands of people around the world experimenting with the medium. Comparatively, there’s very little experimentation happening with audio and VR.

The technology is still catching up. Most VR users and developers use headphones, given that it is a personal experience. Binaural audio, which works great over headphones is a perfect fit for VR. Many of the long standing problems with real-time synthesised binaural audio can be overcome thanks to the head and positional tracking sensors and algorithms in VR devices.

Binaural or positional 3D audio makes a huge difference to the virtual reality experience. There was a lot of commercial work around binaural audio in the 90s but it has since retreated into academic and research spheres. Much of our work at Two Big Ears is making such technology (and many more) work really well across game engines, operating systems and hardware devices. It’s not just about having a straight up binaural panner, but also about advanced audio algorithms that can help create a more realistic experience.

From a design perspective, audio for VR is very much an open book. Many of the game design principles (especially those related to FPS games) crumble in virtual reality. I’m curious to see what can be uncovered for audio. For example, I’ve personally found the idea of depicting the scale of objects through sound very intriguing. With binaural audio, the space around the player becomes another parameter to play with. There’s lots that needs to be defined for mixing too. Creating a real-time binaural mix over headphones is very different to mixing on speakers.

How does sound for a 360 degree film work? Nobody is entirely sure! That’s the exciting part!

Outside the scope of games, there’s much work that needs to be done with VR films too. How does sound for a 360 degree film work? Nobody is entirely sure! That’s the exciting part!

What are some of the challenges presented by audio in virtual reality?

Designing visuals for VR needs to be treated as a different process (rather than upgrading existing content to support VR) and I’m convinced that the same applies for audio too. A lot of the techniques we take for granted, such as designing sounds for menu screens or HUD elements might not be applicable any more. Quite a few of the VR games are leaning towards user interface elements existing within the virtual space around the player. Could sound be used to draw attention to them?

Another area that has seen almost no discussion is music. How do we treat a background score? Must it be diegetic and exist within the scene? Could it just be a ‘normal’ stereo track in the background? Foley is an interesting area too. Could it be used to help achieve presence in a scene?

Technologically there are challenges too. Game audio needs a real push across the whole stack. We are working hard at it and so are our competitors =) The next few years are going to be an interesting time for audio.
 

As a sound designer for VR, how do you achieve presence and spatialization in your sound design?

For spatialisation we have to rely on technology. Binaural rendering and room modelling makes a massive difference. Although, the spatialisation effect itself can be greatly enhanced by the quality of the sounds. I don’t just mean recording quality, but the timbre and envelope of the sound. As humans, we’re better at localising sounds with higher mid and high frequency content. HDR mixing and ducking can help massively in clearing up a mix.

As for presence — I’m not entirely sure yet. Spatialisation helps, but I feel generative, procedural and dynamic content can greatly improve the experience. I’m personally interested in seeing how input devices for VR evolve. I’m always looking for ways to map sensor data to sound!
 

Outside of games, what are some of the areas where you envision VR being used – and how does audio fit into those scenarios?

There’s been a lot of talk lately about education and it is quite easy to see the impact VR can have on it. I also think it can redefine audio post-production, especially with VR movies. We would have to lean towards using game audio tools, but in many ways they can be inadequate for a structured and curated experience.

Being a long time advocator of procedural and generative audio techniques, I think there will be a strong need for those techniques too. Somebody just needs to create the tools that will help us move beyond vehicle, impact, rain and gun-shot models. It is tough work, but it needs getting done. If I had more time in a day, I’d be spending all of it on that!

If sound designers want to get started doing sound for VR, how do they go about it?

It is tough to design for VR without a device — so getting access to one would be a good place to start :) The audio tools exist and are constantly being improved upon. I think it would be great for sound designers to also jump into the video game development process, with game engines like Unreal Engine 4 that have a low price barrier — picking up those skills can help when communicating with the rest of the game development team too.

We definitely need more sound designers breaking new ground, failing, iterating and pushing the medium forward.

Another approach would be to work with the many VR enthusiasts around the world. There are lots of great indie projects around the web and I’m sure they would all value the contribution of a sound designer.

We’ve found that a number of the VR developers around the world care a lot about audio and they are willing to experiment with new technology and techniques.

We definitely need more sound designers breaking new ground, failing, iterating and pushing the medium forward.

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About Varun Nair

Varun has worked on over 400 projects in films, games and advertising and music. He’s the co-founder of Two Big Ears, a company developing advanced audio solutions for games and VR. They offer 3Dception, a unique binaural audio and room modeling solution for game engines and middleware.