Perceptual Evaluation of Mitigation Approaches of Impairments Due to Spatial Undersampling in Binaural Rendering of Spherical Microphone Array Data: Dry Acoustic Environments

Tim Lübeck; Hannes Helmholz; Johannes Mathias Arend; Christoph Pörschmann; Jens Ahrens
DAFx-2020 - Vienna (virtual)
Employing a finite number of discrete microphones, instead of a continuous distribution according to theory, reduces the physical accuracy of sound field representations captured by a spherical microphone array. For a binaural reproduction of the sound field, a number of approaches have been proposed in the literature to mitigate the perceptual impairment when the captured sound fields are reproduced binaurally. We recently presented a perceptual evaluation of a representative set of approaches in conjunction with reverberant acoustic environments. This paper presents a similar study but with acoustically dry environments with reverberation times of less than 0.25 s. We examined the Magnitude Least-Squares algorithm, the Bandwidth Extraction Algorithm for Microphone Arrays, Spherical Head Filters, spherical harmonics Tapering, and Spatial Subsampling, all up to a spherical harmonics order of 7. Although dry environments violate some of the assumptions underlying some of the approaches, we can confirm the results of our previous study: Most approaches achieve an improvement whereby the magnitude of the improvement is comparable across approaches and acoustic environments.