Binaural sound
In the ever-evolving soundscape of the audio industry, at Crown Lane, we’re always keeping our ear to the ground for two reasons: firstly, we want to be ahead of the curve – successful, efficient and creative in our field and second, we don’t want to find ourselves outdates and and irrelevant.
Even since my [Chris] degree focusing on Binaural Audio and its applications in 2018, the world of audio has changed dramatically. With new technologies and methodologies seemingly introduced monthly or even weekly, as a studio with clients from the BBC to the West End utilising 3D audio, we don’t want to miss the next big jump in the industry which could lead to irrelevance or outmoding.
Binaural audio has reared its head many times in recent history, appearing in many forms from recording methods to post-production mixing techniques. Its biggest, most recent resurgence has come in the form of Apple’s Spatial Audio introduction during their WWDC 2020 announcement – meaning Apple Product users could now experience “Dynamic Binaural Audio” commercially for the first time…only if you had the correct gear and this highlighted some very prominent limitations which we’ll address a little later.
What is binaural audio?
Binaural audio references a combination of recording and mixing techniques to produce a stereo sound signal which, through psychoacoustics, can create a very realistic simulation of being in another space. Notably, this has to be experienced through headphones which can also be a limiting factor.
After sight, we rely on our sense of hearing to experience the world around us. Through what we call early-reflections and our brain translating two audio signals from both our ears working together we can perceive room sizes and our orientation in it, the distances and locations of things or people around us and the direction they’re travelling.
How do I record binaural audio?
In order to record a sound as a binaural signal, you’ll need a binaural microphone which consists of two capsules usually housed in ear-shaped casing with the space of an average head (or with a head shaped module) between them. Notable examples of this are the Neumann KU-100 and 3Dio Free Space. There are also cheaper options like the Roland CS-10EMs that allow you to be the module that houses the microphones in your ears and monitor the audio at the same time!
How do I mix binaural audio?
While you can record audio using the microphones mentioned above, they can be expensive (up to £8000) or achieve a lower recording quality than desired. They also require all the intended sound elements to be present at the same time and no unwanted audio sources – the perfect environment, which is difficult or even impossible to create. You can instead choose to mix your audio in post-production using binaural editing software to locate even mono audio sources on a three dimensional soundscape. Logic Pro X has introduced basic binaural mixing capabilities and other third-party plug-ins have also utilised early-reflections and ambisonics to create such 3D soundscapes such as Sound Particles’ Space Controller which we use here at Crown Lane Studio when working in Pro Tools.
What are the pros and cons of binaural audio?
Binaural Audio only works using headphones. If listening to a binaural recording in a room, the room’s own acoustics would blur and reduce the effects of the 3D panning and situate sources differently than intended. Binaural Audio also doesn’t automatically translate to audio formats such as Dolby Atmos and would take further mixing and encoding in order to make it accessible to an Atmos sound system or similar configuration.
“Dynamic Binaural Audio” which places the user in a dynamic soundscape that uses head tracking through GPS reacts to the listeners movement for a more immersive experience but requires headphones/earphones with the functionality to do so. This has worked really well with the rise of VR but is limited in its experience when paired with a monitor that only covers a small field of vision.
Today, should my mix be binaural?
Under specific conditions, the answer is yes!
If you’re looking for an immersive experience for individual listeners, then Binaural Audio will allow your listener to be drawn into the soundscape you have spent all your time creating for them. This pairs really well with 3D visuals too so it’s an even more compelling option if you are going down the route of VR and immersive experience. However, for the average everyday-listener consuming audio on their laptop or the daily commute seeking a passive listening experience to pass the time, immersive audio may be too demanding to their already limited attention.
