Distributed Microphone Networks for sound source localization in smart rooms
| Author: |
Brutti, Alessio |
| Advisor: |
Omologo Maurizio |
| URL: |
http://shine.itc.it/people/brutti/Brutti_Thesis.pdf
" target="_blank"> http://shine.itc.it/people/brutti/Brutti_Thesis.pdf
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| Completion Date: |
March 2007 |
| Degree: |
Ph.D. |
| Institution: |
Universita' di Trento, Trento, Italy |
| Abstract: |
This PhD thesis describes a research activity on distributed networks of sensors for acoustic source localization in enclosures. The problem can be addressed through the so called ubiquitous computing, as envisioned in the CHIL project framework, in an effort to make the users unaware of the underneath audio processing. A specific goal of this research is hence to design an algorithm able to estimate the position of active speakers during meetings and seminars held in rooms which are quite critical from an acoustic point of view. As a matter of fact, reflections and scattering by objects and walls critically affect the quality and characteristics of the signals received by far microphones. The problem is tackled by distributing a set of microphones in the given room in order to always ensure a good coverage of the concerned area. This approach requires to devise an algorithm able to handle all the inputs, possibly discordant, delivered by the network of sensors.
Estimation of time delay of arrival based on generalized cross correlation has been proved to be an effective approach to the sound source localization task. A novelty introduced in this doctoral research is the attempt to characterize the source orientation by exploiting the shape of the Global Coherence Field around a candidate source position. Once the orientation is determined, microphone contributions can be merged in a more efficient way, with emphasis on frontal microphone pairs. A further effort was devoted to investigate an approach which characterizes the source position and orientation on the basis of some previously calculated acoustic models. In this way it is possible to take advantage also of the reverberation pattern and to deal with situations in which a direct path from source to receiver is not available. |
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