102 research outputs found
A survey of sound source localization methods in wireless acoustic sensor networks
No full textWireless acoustic sensor networks (WASNs) are formed by a distributed group of acoustic-sensing devices featuring audio playing and recording capabilities. Current mobile computing platforms offer great possibilities for the design of audio-related applications involving acoustic-sensing nodes. In this context, acoustic source localization is one of the application domains that have attracted the most attention of the research community along the last decades. In general terms, the localization of acoustic sources can be achieved by studying energy and temporal and/or directional features from the incoming sound at different microphones and using a suitable model that relates those features with the spatial location of the source (or sources) of interest. This paper reviews common approaches for source localization in WASNs that are focused on different types of acoustic features, namely, the energy of the incoming signals, their time of arrival (TOA) or time difference of arrival (TDOA), the direction of arrival (DOA), and the steered response power (SRP) resulting from combining multiple microphone signals. Additionally, we discuss methods not only aimed at localizing acoustic sources but also designed to locate the nodes themselves in the network. Finally, we discuss current challenges and frontiers in this field
Synchronization Ambiguity in Audio Content Generated by Users Attending the Same Public Event
No full textExploiting correlations in the audio, several works in the past have demonstrated the ability to automatically match and synchronize User Generated Recordings (UGRs) of the same event. The synchronization process is of fundamental importance as it provides the basis for combining the different sources of content in order to improve the audiovisual experience of the captured event. In this paper, we show that depending on the complexity of the sound scene, the time offsets required to synchronize the audio recordings are not unique, and depend on the locations and the activity of the sound sources. We use simulation results to illustrate that this problem is very likely to occur in athletic events and we demonstrate how it may impair the listening experience
Improving narrowband DOA estimation of sound sources using the complex Watson distribution
No full textNormalization of Partly Overlapping Audio Recordings from the Same Event Based on Relative Signal Powers
No full textExploiting correlations in the audio, several works in the past have demonstrated the ability to automatically match and synchronize user-generated video or audio files of the same event. Such tools solve for the unknown starting and ending time of each available recording along the event time-line and open the way for collaborative content production approaches. However, a source of difficulty for collaborative processing approaches related to audio is the fact that the different audio recordings may be available at significantly different signal levels. In this paper, we present a normalization approach to automatically define gains for all the recordings so that the variations in the signal levels among different recordings are suppressed. We show that normalization is trivial when all recordings share the same time support but the same process is non-trivial when the recordings partly overlap along time, especially if the acoustic event is characterized by high dynamic variations. We demonstrate the efficiency of the proposed approach under various conditions based on real examples of user-generated audio recordings
Multiple sound source location estimation and counting in a wireless acoustic sensor network
No full textLocalizing multiple audio sources from DOA estimates in a wireless acoustic sensor network
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