Synchronization of Microphones Based on Rank Minimization of Warped Spectrum for Asynchronous Distributed Recording
Katsutoshi Itoyama, Kazuhiro Nakadai
Abstract
This paper describes a new method for synchronizing microphones based on spectral warping in an asynchronous microphone array. In an audio signal observed by an asynchronous microphone array, two factors are involved: the time lag caused by a mismatch of the sampling rate and offset between microphones, and the modulation caused by differences in spatial transfer function between the sound source and each microphone. A spectrum warping matrix representing a resampling effect in the frequency domain is formulated and an observation model of audio (spectrum) mixture in an asynchronous microphone array is constructed. The proposed synchronization method uses an iterative optimization algorithm based on gradient descent of a new objective function. The function is formulated as a logarithmic determinant of a spectrum correlation matrix that is derived from relaxation of a rank minimization problem. Experimental results showed that the proposed method effectively estimates modulated sampling rate and that the proposed method outperforms an existing synchronization method.
BibTeX
@inproceedings{iros2020_synchronizationo,
title = {Synchronization of Microphones Based on Rank Minimization of Warped Spectrum for Asynchronous Distributed Recording},
author = {Katsutoshi Itoyama and Kazuhiro Nakadai},
booktitle = {IROS 2020},
year = {2020}
}