Spatial audio

Space-time processing of audio signals involves the processing of signals acquired or reproduced by arrays of microphones and loudspeakers in order to capture properties of the sound field (source localization, separation, etc.) or to render sound fields. Several are the applications of space-time processing, listed in the following.

Members of the research team:

Person Interests

Prof. Augusto Sarti

Associate Professor


Dr. Fabio Antonacci

Assistant Professor


Dr. Paolo Bestagini

Assistant Professor

Distributed Microphone Networks

Dr. Antonio Canclini

postdoc researcher

Distributed Microphone Networks, Acoustics of Musical Instruments, Acoustic scene rendering

Dr. Dejan Marković

postdoc researcher

Acoustic scene analysis, modeling of acoustic propagation in complex environments

Dr. Marco Compagnoni

postdoc researcher

Mathematical modeling of space-time processing algorithms

Ing. Muhammad Shahnawaz

PhD student

Binaural Rendering, Head Related Transfer Function
Ing. Federico Borra Acoustic Scene Analysis

Research themes

  • Distributed Microphone Networks

    The use of low-cost devices for acquisition of audio streams is becoming widespread. In this context, the space-time processing research community is interested to enable functionalities such as source localization and separation, denoising etc. on such devices, to keep at bay the cost of equipment. The research activity of ISPG aims at attaining this goal with ad-hoc algorithms to overcome the inherent challenges that pop up when one intends to use multiple independent devices. In particular, the research activity focuses on synchronization of streams acquired with different clocks, self-calibration, and reduction of the computational cost of space-time processing algorithms.

  • Acoustics of Musical Instruments

    The activity of ISPG in the Musical Acoustics lab in Cremona is twofold: on one side state-of-the-art analysis techniques are used to measure acoustic parameters of instruments. Vibrometric measurements using laser vibrometer or accelerometers and instrumented hammer are used to estimate in a short time the patterns of vibration modes. On the other side ISPG focuses also on innovating the measurement methodology, thanks to the achievements attained in the space-time processing research area. An exemplary case is the introduction of a novel technique for the measurement of the radiation pattern of violins, which does not require the instrument to be played by mechanical bows and does not constrain the player to unnatural poses.

  • Mathematical modeling of space-time processing algorithms

    Starting from 2010, ISPG collaborates with researchers from Dept. of Mathematics in Politecnico di Milano. The goal is to shed light on the mathematical aspects of space-time processing algorithms, such as source localization from Time Differences Of Arrival. This task is accomplished through formalization, in mathematical terms, of the measurement space (e.g. TDOAs), and of the map from the measurement space to the source locations with tools from algebraic geometry, computational algebraic geometry, information geometry and statistical geometry. This analysis enables to obtain useful information about estimators, such as their robustness against noise, and also to innovate existing estimators, to attain a better performance in terms of accuracy, computational stability, etc.
  • Acoustic Scene Analysis and Rendering

    The use of microphone arrays for the analysis of acoustic scenes has been a hot research topic for the last twenty years. Recently, ISPG has developed the plenacoustic framework: a representation of the sound field as a function of time, space, and direction of propagation, in which acoustic primitives of interest (such as sources, receivers, reflectors, etc.) are conveniently represented as linear patterns. It is therefore easier in this framework to perform tasks such as source localization, localization of reflectors and obstacles, extraction of acoustic sources from mixtures, etc. ISPG also works on the rendering of acoustic scenes through loudspeaker arrays. In this context different methodologies have been proposed, the most recent of which is based on the use of the plenacoustic framework.
  • Modeling of propagation in complex environments

    Accurate and fast tracing acoustic paths from source to listener in complex environments is of great interest to architects and engineers to predict the acoustics of complex environments, such as auditoria, cinemas, theatres, etc. before their building. Moreover, accurate modeling of propagation is crucial for the rendering of virtual environments, e.g. immersive gaming and walkthrough. Inter In the last ten years ISPG has developed methodologies for accurate and fast tracing of acoustic beams based on a pre-computation of the mutual visibility between walls of the environment. Once this information has been computed in advance, and source and receiver locations are specified, the tracing of acoustic paths consist of a simple lookup on the pre-computed data structure. Techniques have been developed for both complex 3D and 2D environments.
  • Binaural Rendering

    In order for a binaural stream to deliver the sense of presence, a suitable modeling of the Head Related Transfer Function (HRTF) must be implemented, which models the response of the ear of the listener to sounds incoming from different directions. Every person has its own HRTF, and the use of a wrong HRTF impairs the listening experience. ISPG is developing techniques for accurate and simple personalization of the HRTF, by means of both direct measurement and prediction.

Journal Publications

  • F. Setragno, M. Zanoni ,  F. Antonacci, A. Sarti, M. Malagodi, T. Rovetta, C. Invernizzi, "Feature-based analysis of the impact of ground coat and varnish on violin tone qualities", Acta Acustica united with Acustica, volume 103, Issue 1, Jan. Feb. 2017, pp. 80-93
  • M. Compagnoni, R. Notari, , A.A. Ruggiu,  F. Antonacci, A. Sarti, "The Algebro-geometric Study of Range Maps", Journal of Nonlinear Science, volume 27, Issue 1, Feb. 2017, pp. 99-157
  • D. Marković, F. Antonacci, L. Bianchi, S. Tubaro and A. Sarti, "Extraction of Acoustic Sources Through the Processing of Sound Field Maps in the Ray Space," in IEEE/ACM Transactions on Audio, Speech, and Language Processing, vol. 24, no. 12, pp. 2481-2494, Dec. 2016. doi: 10.1109/TASLP.2016.2615242
  • L. Bianchi, F. Antonacci, A. Sarti and S. Tubaro, "The Ray Space Transform: A New Framework for Wave Field Processing," in IEEE Transactions on Signal Processing, vol. 64, no. 21, pp. 5696-5706, Nov.1, 1 2016. doi: 10.1109/TSP.2016.2591500
  • M. Compagnoni, A. Canclini, P.Bestagini, F. Antonacci, A. Sarti, S. Tubaro, "Source localization and denoising: a perspective from the TDOA space", Multidimensional Systems and Signal Processing, 2016, pp. 1-26, doi 10.1007/s11045-016-0400-9
  • L. Bianchi, F. Antonacci, A. Sarti, S. Tubaro, "Model-Based Acoustic Rendering based on Plane Wave Decomposition", Applied Acoustics 104 (2016) Elsevier , pp. 127-134, doi: 10.1016/j.apacoust.2015.10.010
  • D. Marković, F. Antonacci, A. Sarti and S. Tubaro, "3D Beam Tracing Based on Visibility Lookup for Interactive Acoustic Modeling," in IEEE Transactions on Visualization and Computer Graphics, vol. 22, no. 10, pp. 2262-2274, Oct. 1 2016. doi: 10.1109/TVCG.2016.2515612
  • D. Markovic, F. Antonacci, A. Sarti, S. Tubaro, "Multiview Soundfield Imaging in the Projective Ray Space," IEEE/ACM Transactions on Audio, Speech, and Language Processing , vol.23, no.6, pp.1054,1067, June 2015 doi: 10.1109/TASLP.2015.2419076
  • A. Canclini, P. Bestagini, F. Antonacci, M. Compagnoni, A. Sarti, S. Tubaro, "A Robust and Low-Complexity Source Localization Algorithm for Asynchronous Distributed Microphone Networks," IEEE/ACM Transactions on Audio, Speech, and Language Processing , vol.23, no.10, pp.1563--1575, Oct. 2015, doi: 10.1109/TASLP.2015.2439040
  • A.Canclini, D.Marković, L.Bianchi, F.Antonacci, A.Sarti and S.Tubaro, "A Robust Geometrical Approach to Room Compensation for Sound Field Rendering", in IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol. 2014, no. 9, pp. 1884-1892, 2014
  • M.Compagnoni, R.Notari, F. Antonacci, A. Sarti, "A comprehensive analysis of the geometry of TDOA maps in localisation problems", Inverse Problems, IOP Science, volume 30, pages 1-49
  • D. Marković, K.Kowalzcyk, F.Antonacci, C.Hoffman, W.Kellermann, A.Sarti "Estimation of acoustic reflection coefficients through pseudospectrum matching", IEEE/ACM Transactions on Audio Speech and Language Processing, volume 22, issue 1
  • D. Marković, F. Antonacci, A. Sarti, S. Tubaro, "Soundfield imaging in the ray space" IEEE/ACM Transactions on Audio, Speech and Language Processing, volume 21, issue 12
  • A. Canclini,F. Antonacci, A. Sarti, S. Tubaro, "Acoustic Source Localization with Distributed Asynchronous Microphone Networks", in IEEE Transactions on Audio, Speech and Language Processing, volume 21, issue 2, Feb. 2013
  • P. Bestagini , M. Compagnoni, F. Antonacci, A. Sarti, S. Tubaro, "TDOA-Based Acoustic Source Localization in the Space-Range Reference Frame", Multidimensional Systems and Signal Processing, March 2013, doi 10.1007/s11045-013-0233-8
  • M.Compagnoni, P.Bestagini, F. Antonacci, A.Sarti, S.Tubaro, “Localization of Acoustic Sources through the Fitting of Propagation Cones using Multiple Independent Arrays”, IEEE Transactions on Audio, Speech and Language Processing, volume 20, issue 7, Sept. 2012
  • F. Antonacci, J. Filos, M. R. P. Thomas, E. A. P. Habets, A. Sarti, P. A. Naylor and S. Tubaro (2012), "Inference of Room Geometry from Acoustic Impulse Responses," IEEE Transactions on Audio, Speech and Language Processing, volume 20, issue 10, Dec. 2012, pp. 2683-2695
  • L.An, P.Wang, A. Sarti, F.Antonacci, J.Shi, “Hyperbolic boiler tube leak location based on quaternary acoustic array”, Elsevier J. of Applied Thermal Engineering, volume 31
  • F.Antonacci, A.Sarti, S.Tubaro, “Two-dimensional beam-tracing from Visibility Diagrams for Real-Time Acoustic Rendering”, EURASIP Journal on Advances in signal Processing (ISSN: 1687-6172), 2010, pages 1-18
  • F.Antonacci, M.Foco, A. Sarti A, S. Tubaro, “Fast Tracing of Acoustic Beams and Paths Through Visibility Lookup”, IEEE Transactions on Audio, Speech and Language Processing, vol. 16, 4; p. 812-824, ISSN: 1558-7916