Enhanced diffuse field model for ad hoc microphone array calibration

Mohammad Javad Taghizadeh, Philip N. Garner, Hervé Bourlard

Abstract: Highlights • Averaging and histogramming improve the diffuse field coherence model for calibration. • A novel approach for assessment of the adequacy of diffuseness is formulated. • The relation between distance, enclosure dimension and diffuseness is characterized. • A methodology for augmenting the diffuse sound field is proposed. • Fundamental limitation of calibration based on the coherence model is analyzed. Abstract In this paper, we investigate the diffuse field coherence model for microphone array pairwise distance estimation. We study the fundamental constraints and assumptions underlying this approach and propose evaluation methodologies to measure the adequacy of diffuseness for microphone array calibration. In addition, an enhanced schemebased on coherence averaging and histogramming, is presented to improve the robustness and performance of the pairwise distance estimation approach. The proposed theories and algorithms are evaluated on simulated and real data recordings for calibration of microphone array geometry in an ad hoc set-up.