Brief Production Writeup - Ideation Process
In our first week of the module we were tasked to produce an asset pack for a film, this consisted of ADR recordings, sound design packs, foley backgrounds, walla / loop groups, and music for four scenes. Working as a production team we divided the assets up, meaning I was responsible for producing the alternatives for foley backgrounds and sound design. The ADR was then scheduled to be recorded in the Neve / Audient studios along with the loop group assets.
For the production of the assets I was tasked with, I decided on exploring an area of audio which I am interested in regarding to the research and professional development module. The spacial and surround sound that can be reproduced through stereo playback is an area of sound design that I’ve had avid interest in, and have engaged with before in previous modules including our use of Dolby Atmos for the production of an animated short-film soundtrack, as well as in my own music production and mixing work alongside studies. For the production of these assets I wanted to employ some of my current understanding of spatial imaging within stereo with ambisonic encoding, as an inquiry into the subject whilst I am brainstorming for the research module.
For the practical application of this I utilised directional imaging to position sound sources in a space around the listener, rendered using Apples imaging plugins, the encoders of which would be subject to investigation. This differs from stereo balancing / panning by positioning the incoming audio source within a 3D rendering environment. This rendering environment is similar to the rendering environment found in Dolby Atmos, used to drive multi-output surround sound speaker systems or playback via decoding for binaural over headphones. However the difference in playback is that despite neither including height information in stereo format, the directional imaging and encoding of ambisonics produces much more definition of spatial and directional positioning of sound sources around the listener in stereo playback compared to regular stereo panning. The positioning of the stereo bed within a rendered space opens up the acoustic room for track positioning across the full width of the stereo field to a high precision for immersive and surround experience without the need for large expensive playback setups or decoding software.
Within the assets, different spatial configurations have been designed to highlight and emphasise the practical effects of this technique.
I have found applications for this across all my audio production and with the opportunity to investigate it further if possible with my research would be a huge benefit to my professional development.
With regard to the Ideation process across the MPP, this is where I intend to go with the self-directed research topic. For this mini-project brief I began to look into various areas of encoding for spatial audio positioning, I found a good repository of technical information and it has struck a particular interest of mine which has followed me through my development in audio engineering.
To be concise, encoding for spatial audio positioning refers to digital audio processing that incorporates a :
- Virtual 3D Rendering Environment
- Directional sound source (image)
- HRTF (receiver)
Functions such as this are integrated into audio processing for surround sound playback, utilising similar spot (image) sourcing to place sound then rendered to the focal (receiver). This is also most commonly implemented into videogames running game engines from the last decade, where sound appears to the listener as directional around 360°, as the audio technologies that have arose around this function typically are designed as software integration with engines for videogame developers (Steam Audio, FMOD Spatialiser, Unreal’s Sound Attenuation).
This area of audio processing however has only begun to be fully realised in the music audio engineering sector. Although surround sound technologies such as Dolby Atmos or Apple’s Spatial have gained significance in producing multi-channel surround formatted audio intended for either surround sound playback or binaural, as for (eg) Dolby’s rendering environment, there is no indication of it then also imparting acoustic information similarly to what would be expected in a game engine implementation or live acoustic performance. To do this effectively It also does not require multi-output playback arrays to hear these intended effects, although playback medium does play a significant role in the final auditory experience, both stereo speaker playback and headphone playback can benefit from the increased spatial definition which is imparted through this process.
This area of audio is where I intend to investigate over my major project, as it appears to me that there is a gap in spatial processing standards between audio for videogames and music. The scope of my project will cover an investigation into various encoding processors and methods based on the above specified function. I aim to develop an implementation of this which can be utilised with addition of virtual acoustic information imparted by a designed virtual rendering environment, for music audio engineering. As well as a researched and informed process to do this, I will set out to create a number of virtual 3D rendering environments (small / medium / large) with distinct virtual acoustic properties. I will most likely use a game engine to produce the software based implementation, which audio can then be bounced through similarly to any other audio effects processor. The aim for the creative and practical output then is to also produce a number of demos utilising this processing, with placements being focused on spacing and the virtual acoustics, rather than automated positional movement.
Here is an example (utilising the mini brief deliverables) using directional sound source imaging to HRTF receiver, from a rudimentary setup with no implemented rendering environment or virtual acoustic properties :
https://drive.google.com/file/d/1SI-E7k6iqxXEqdPx1hhrmr7MaSfIKOXG/view?usp=share_link
