A Blind Dereverberation Method for Narrowband Source Localization

Abstract

Narrowband source localization gets extremely challenging in strong reverberation. When the room is perfectly known, some dictionary-based methods have recently been proposed, allowing source localization with few measurements. In this paper, we first show that, for these methods, the choice of frequencies is important as they fail to localize sources that emit at a frequency near the modal frequencies of the room. A more difficult case, but also important in practice, is when the room geometry and boundary conditions are unknown. In this setup, we introduce a new model for the acoustic soundfield, based on the Vekua theory, that allows a separation of the field into its reverberant and direct source contributions, at the cost of more measurements. This can be used for the design of a dereverberation pre-processing step, suitable for a large variety of standard source localization techniques. We discuss the spatial sampling strategies for the sound field, in order to successfully recover acoustic sources, and the influence of parameters such as number of measurements and model order. This is validated in numerical and experimental tests, that show that this method significantly improves localization in strong reverberant conditions.

Flux projection beamforming for monochromatic source localization in enclosed space

“…2(c) and 2(d) can not be discerned for this single frequency. Note that the performance of the beamforming in the enclosed space is effective by using multiple frequencies, which has been discussed by Chardon et al 8 Finally, the source localization for a general situation is illustrate by a numerical simulation. The simulation parameters are shown in Fig.…”

“…For a monochromatic source in the enclosed space, the beamforming method was not effective. And Chardon et al proposed a blind dereverberation method 8 to remove reverberation by the projection operation, with an assumption that the sound field can be decomposed into the radiated sound by sources in free space and the reverberant sound generated by multiple reflections of the boundary. Once the reverberation is eliminated, the location of sound source, even for the monochromatic source, can be achieved by the traditional localization methods.…”

Design of Audio Digital Watermarking System Resistant to Removal Attack

“…It is worth to note that an operation to remove a reverberation from an audio signal is called blind dereverberation. This problem was investigated in many papers [8], [9], [10], [11], [12], [13] and others. But the goal of such signal transform was to make the audio signal free from additional reverberation interference that may occur in a natural manner.…”

Membrane shape and boundary conditions estimation using eigenmode decomposition

“…Several applications of Vekua theory have been proposed recently, for example to perform impulse response interpolation inside a measurement domain D [22], or to cancel reverberation coming from the boundaries for acoustic source localization [23]. In [19], we used eigenmode decomposition to perform array position calibration.…”