«
»

5. The PoPi plane

The idea:
Although unvoiced sounds of speech dominanting at high frequencies (sounds “s” “z” “f”, etc) give very clear DoA estimation, the real information is still hidden in the not-so-clear and confusing micro-periodicities of the autocorrelation. These microperiodicities carry the information not only about the DoA of the source they are related to, but also its pitch information. This means, even in case of two moving, not always active acoustic sources, their ID could be described to their position by linking their pitch to their DoA.

Method Description:
Decomposing a frame of a 2-channel acoustic signal into a Position-Pitch plane shows clearly where the source is (at which DoA angle) and what the Pitch (from correlation lag) of that speaker is. The image below demonstrates a PoPi plane extracted by a 16-channel circular mic array signal for a voiced speech frame.

picture-13

References:
[1] M. Képesi, F. Pernkopf, M. Wohmayr, “Joint Position-Pitch Tracking for 2-Channel Audio,” CBMI 2007, Jun 25-27, Bordeaux, France
[2] M. Wohmayr, M. Képesi, “Joint Position-Pitch Extraction from Multichannel Audio,” Proc. Interspeech 2007, August 27-31, Antwerpen, Belgium
[3] M. Képesi, M. Wohmayr, T. Habib, “Pitch-Driven Position Estimation of Speakers in Multispeaker Environments,” The 3rd Congress of the Alps Adria Acoustics Association, September 27-28, 2007, Graz, Austria
Related work:
[4] T Habib, H Romsdorfer: Comparison of SRP-PHAT and multiband-POPI algorithms for speaker localization using particle filters, Proc. DAFX, 2010 – dafx10.iem.at
[5] Stephan Gerlach, Stefan Goetze1, Jörg Bitzer and Simon Doclo: Evaluation of Joint Position-Pitch Estimation Algorithm for Localising Multiple Speakers in Adverse Acoustical Environments, ICASSP, 2011, Prague
[6] MG Christensen, JX Zhang, SH Jensen: Joint DOA and Multi-Pitch Estimation based on Subspace Techniques, EURASIP Journal on Advances in Signal Processing 2012, 2012:1
[7] T Habib, H Romsdorfer: Auditory Inspired Methods for Localization of Multiple Concurrent Speakers, Computer Speech & Language, 2012
More publication
… under the Multichannel PoPi topic.

Patents:
EP2162757B1 – Kepesi, Wohlmayr, Kubin: JOINT POSITION-PITCH ESTIMATION OF ACOUSTIC SOURCES FOR THEIR TRACKING AND SEPARATION
US8107321B2 – Kepesi, Wohlmayr, Kubin: JOINT POSITION-PITCH ESTIMATION OF ACOUSTIC SOURCES FOR THEIR TRACKING AND SEPARATION

Links:
[1] Related page at SPSC (if it is not there, it is not there…)
[2] PoPi Demo Videos and Audio Files
[3] Elmar using the method for controlling the orientation of his robot.

Code:
[1] Simple and Fast Demo

This entry was posted on December 7, 2008 at 10:32 am and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

Leave a comment