Binaural audio and its future potential in video games.

Binaural audio as defined by Hooke Audio (2020) is audio captured identically to the way we hear the world in a realistic 3D state, mobile audio and the hardware that allows for it have been increasing in popularity since the availability and higher quality of devices such as iPods, smartphones and iPads, and the idea of immersive audio through the use of headphones has further increased in popularity because of this and the effort to make binaural audio features assessable have recently been popping up in the video game industry.

The earliest signs of an attempt at realistic lifelike binaural audio can date back to 1881 when Clement Adler created the Théâtrophone a system in which opera-goers can listen in to the performance through a pair of two phone lines, one for each ear. These phone lines would receive transmissions from microphones close to the stage and would send audio to distances of up to 2 miles away. These systems were a success and were soon built in cities all over Europe and even occasionally homes of those who could afford it.

Figure 2 - Drawing of early théâtrophone. An illustration from Le Magasin pittoresque (1892).

A common misconception is that stereo sound is the same as binaural, however, they are different in both recording techniques and results. Stereo allows for listeners to identify sounds left and right depending on volume, binaural however allows for listeners to identify sound sources in front of them, behind them, above and below. The binaural recording also takes into account interaural time differences (or ITD's), ITD's are delays and small other audio disparities that occur due to certain differing physical aspects of the listener, these could include things such as head or ear size and rotation. This is what allows binaural audio to surpass standard stereo audio in immersion and realism.

Hell Blade Seuna's Sacrifice

Hellblade Seuna's Sacrifice (2017) is a game created by British game development company Ninja Theory, the game won a plethora awards from notable associations such as The Baftas, Webbys and The Game Awards for both its gameplay and storytelling but more notably its audio design. One of the main reasons it was so highly regarded was that the game was one of the first triple-A titles to use binaural audio as a core feature of its design, the audio team at Ninja Theory used "Dummy Head" microphones (as can be seen in figure 3) to record the binaural audio for the game.

Figure 3 - Neumann KU 100 Dummy Head with binaural stereo microphone

The game follows its main protagonist Seuna through a journey to lift a curse, battling through both physical and mental demons along the way, the Ninja Theory team wanted mental health to be a big focus on the title attempting to convey the feelings and issues a person suffering from psychosis may experience through the eyes and ears of Seuna. Binaural audio made great sense here, as it allows for dimensional audio to move in an eerily lifelike way as if someone or something is constantly whispering in one or two your ears.

Figure 4 - Screen shot of gameplay from Ninja Theory's Hellblade Seuna's Sacrifice.

Binaural audio still has its limitations however as the sound recorded using the dummy head microphones that binaural audio typically uses to record with cannot be panned or moved within the game engine as the positions are fixed from the recording. In an interview by The sound architect.com (2017) Ninja Theory creative director Tameem Antoniades mentions almost scrapping the idea of using binaural recordings, but came to think of the player as an observer, an active participant, and concluded that: “If the voices are relevant to us, it doesn’t matter if we move the camera, it still makes sense”.

Conclusion

Binaural audio has shown through works such as Ninja Theory's Hell Blade Seuna's Sacrifice, that it is a tool that can, and is ready to be utilised on game projects even if that is just for niche effects such as the life-like whispering used within Hell Blade. In a media obsessed with constantly making products more immersive through both visuals, design and audio, there is an extremely high chance that we will see an increase in the accessibility and use of binaural audio products such as the Neumann KU100 Dummy Head in future game development projects.

References

Hooke Audio (2020) - https://hookeaudio.com/what-is-binaural-audio/

https://hookeaudio.com/blog/binaural-3d-audio/the-history-of-binaural-audio-part-1/

https://www.mentalfloss.com/article/72920/theatrophone-19th-century-version-livestreaming

https://en.wikipedia.org/wiki/Th%C3%A9%C3%A2trophone

https://www.statista.com/statistics/253725/iphone-ipad-and-ipod-sales-comparison/ (Figure 1)

Hellblade: Seuna's Sacrafice - Setting the Gold Standard for Audio, The Sound Architect.com Alyx Jones (2017)

Ninja Theory - Hellblade Seuna's Sacrafice (2017) PS4, Xbox One and PC.