The Digital Ears: A Binaural Spatialization Plugin
Date
2022-05
Authors
Sumner, Sydney
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Abstract
In the last year, popular music has taken the leap into an “immersive” format again. Streaming services like Apple Music and Tidal are offering “Spatial Audio,” which is mainly branded as Dolby Atmos, a surround sound format intended to fully envelope the listener with sound. Spatial technology aims to produce a similar immersive experience on a range of surround sound set ups, and even headphones.
When replicating spatial audio over headphones, the multi-channel output is “mixed down” in real-time to binaural after analyzing a track’s accompanying metadata. Binaural audio can also be achieved without any prior three-dimensional processing. In binaural synthesis, a more direct approach, a mono audio clip recorded with a typical microphone can be mathematically combined with a quantification of human hearing to place the sound anywhere around the listener. Until recently, binaural synthesis was mainly applied to audio for video games and virtual reality, but could translate to music for a target audience of headphone users.
To test this theory, a “binaural effect” is needed. This effect would function using Head Related Transfer Function (HRTF) measurements that quantify the natural equalization of audio from the human head and torso in a free field listening space. Processing an input clip with the HRTF for the position of the user’s choice, the output would appear to place the source in the new location, giving a sense of spatial audio by manipulating human perception instead of physically extending the listening sphere. The ideal, yes elusive goal of this research was the creation of a “binaural effect” for use as an audio plug-in. While not yet attained, various aspects of digital signal processing, different ways of achieving the desired output, and coding for a VST plug-in will be investigated in pursuit of implementation. Previous attempts to popularize immersive music, relevant immersive playback systems and mixing techniques, and the methods used to develop and implement the software’s algorithms will be surveyed as an accompaniment to the software development.
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Keywords
binaural audio, spatial audio, HRTF, immersive music, digital signal processing, MATLAB, Honors College
Citation
Sumner, S. M. (2022). The digital ears: A binaural spatialization plugin (Unpublished thesis). Texas State University, San Marcos, Texas.