INTERNAL TIME DELAY CALIBRATION OF RIGID SPHERICAL MICROPHONE ARRAYS FOR MULTI-PERSPECTIVE 6DOF AUDIO RECORDINGS


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ERDEM E., Olgun O., HACIHABİBOĞLU H.

IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA), New York, United States Of America, 17 - 20 October 2021, pp.241-245 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/waspaa52581.2021.9632715
  • City: New York
  • Country: United States Of America
  • Page Numbers: pp.241-245
  • Keywords: 6DoF audio, spatial audio, spherical microphones, microphone array calibration, time delay
  • Middle East Technical University Affiliated: Yes

Abstract

Recording navigable or six-degrees-of-freedom (6DoF) audio requires elaborate setups involving multiple microphone arrays capable of recording higher-order Ambisonics (HOA) signals. Rigid spherical microphone arrays (RSMAs) are commonly used for recording HOA. When a number of such arrays are positioned to cover a navigable area, several problems need to be solved: position calibration, orientation calibration, and time delay alignment. There exist several methods addressing each of these problems for arrays comprising pressure microphones. However, these solutions are not directly applicable to a recording setup including multiple RSMAs due to multiple scattering among the spheres. We propose an internal time-delay calibration procedure in the multipole expansion domain for multi-perspective 6DoF audio recording setups comprising multiple RSMAs. We demonstrate the utility of the method via numerical simulations.