Multi-View Source Localization Based on Power Ratios

Despite attracting significant research efforts, the problem of source localization in noisy and reverberant environments remains challenging. Novel learning-based methods attempt to solve the problem by modelling the acoustic environment from the observed data. Typically, appropriate feature vectors are defined, and then used for constructing a model, which maps the extracted features to the corresponding source positions. In this paper, we focus on localizing a source using a distributed network with several arrays of unidirectional microphones. We introduce new feature vectors, which utilize the special characteristic of unidirectional microphones, receiving different parts of the reverberated speech. The new features are computed locally for each array, using the power-ratios between its measured signals, and are used to construct a local model, representing the unique view point of each array. The models of the different arrays, conveying distinct and complementing structures, are merged by a Multi-View Gaussian Process (MVGP), mapping the new features to their corresponding source positions. Based on this unifying model, a Bayesian estimator is derived, exploiting the relations conveyed by the covariance terms of the MVGP. The resulting localizer is shown to be robust to noise and reverberation, utilizing a computationally efficient feature extraction.