H. Wierstorf - Talk at the FORUM ACUSTICUM 2012

Transcript

1. Assessment of the Perception of Synthesized Sound Fields with a Binaural Model Hagen Wierstorf, Alexander Raake, Sascha Spors Quality and Usability Lab Deutsche Telekom Laboratories Technische Universität Berlin June 29, 2011
2. Wave Field Synthesis 0 1 2 3 −2 −1 0 1 2 y (m) x (m) f = 1 kHz ∆x0 = 0.15 m −1 0 1 synthesis of arbitrary sound fields simple calculation of driving functions for source models of the sound field Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 1 / 17
3. Wave Field Synthesis Spatial Sampling 0 1 2 3 −2 −1 0 1 2 y (m) x (m) f = 3 kHz ∆x0 = 0.15 m −1 0 1 spatial sampling leads to aliasing above fal Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 2 / 17
4. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
5. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
6. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
7. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
8. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
9. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
10. Wave Field Synthesis Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 perception is dominated by the first wave front additional wave fronts add coloration (Wittek 2007) and an unnatural room impression Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 3 / 17
11. Focused Sources focused source located between listener and loudspeaker array converges to the focal point and diverges afterwards Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 4 / 17 0 1 2 3 −2 −1 0 1 2 y (m) x (m) −1 0 1
12. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
13. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
14. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
15. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
16. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
17. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
18. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 additional wave fronts arrive at the listener before the desired wave front different perception ⇒ echo artifacts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 5 / 17
19. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 one additional wave front per loudspeaker ⇒ less audible artifacts for smaller arrays (Wierstorf 2010) Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 6 / 17
20. Focused Sources Snapshot of impulse response 0 1 2 3 −2 −1 0 1 2 y (m) x (m) dB −35 −30 −25 −20 −15 −10 −5 0 5 one additional wave front per loudspeaker ⇒ less audible artifacts for smaller arrays (Wierstorf 2010) Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 6 / 17
21. Focused Sources Localization The localization of focused sources is affected by spatial sampling. The additional wave fronts may trigger the ... precedence effect ⇒ the perceived location is dominated by the ends of the loudspeaker array summing localization ⇒ the perceived location is somewhere between the loudspeaker array and the focused source Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 7 / 17
22. Experiment Geometry Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 8 / 17
23. Experiment Method length of loudspeaker arrays: 10 m, 4 m, 1.8 m, 0.75 m, 0.3 m with a distance of 0.15 m between speakers, single loudspeaker as reference (ref) dynamic (head tracking) binaural resynthesis of virtual loudspeakers 6 subjects rating of the attribute pair left vs. right castanets and speech as signal SoundScape Renderer and example stimuli can be found on our BLOG: http://audio.qu.tu-berlin.de Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 9 / 17
24. Experiment Dynamic Binaural Resynthesis measured set of head related transfer functions (HRTF) Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 10 / 17
25. Experiment Dynamic Binaural Resynthesis interpolate and extrapolate HRTF set for desired loudspeaker positions Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 10 / 17
26. Experiment Dynamic Binaural Resynthesis repeat this for every possible head orientation Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 10 / 17
27. Experiment Dynamic Binaural Resynthesis repeat this for every possible head orientation Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 10 / 17
28. Experiment Dynamic Binaural Resynthesis repeat this for every possible head orientation Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 10 / 17
29. Experiment Geometry Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 11 / 17
30. Experiment Results left right ref 0.3 0.75 1.8 4 0.3 0.75 1.8 10 Position Array length (m) Mean rating R = 1 m R = 4 m Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 12 / 17
31. Experiment Results left right ref 0.3 0.75 1.8 4 0.3 0.75 1.8 10 Position Array length (m) Mean rating End of array R = 1 m R = 4 m results can not be explained by precedence effect or summing localization Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 12 / 17
32. Diffraction 0 1 2 3 −2 −1 0 1 2 y (m) x (m) −1 0 1 diffraction depends on the frequency diffraction changes ILD Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 13 / 17
33. Diffraction 0 1 2 3 −2 −1 0 1 2 y (m) x (m) −1 0 1 diffraction depends on the frequency diffraction changes ILD Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 13 / 17
34. Diffraction 0 1 2 3 −2 −1 0 1 2 y (m) x (m) −1 0 1 diffraction depends on the frequency diffraction changes ILD Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 13 / 17
35. Diffraction 0 1 2 3 −2 −1 0 1 2 y (m) x (m) −1 0 1 diffraction depends on the frequency diffraction changes ILD Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 13 / 17
36. Binaural Model investigate the causes of observed undesired localization binaural model after Lindemann (1986a) same parameters used as in the original paper model is part of the Auditory Modelling Toolbox (Søndergaard 2011): http://amtoolbox.sourceforge.net/ Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 14 / 17
37. Binaural Model Results left right ref 0.3 0.75 1.8 4 0.3 0.75 1.8 10 Position Array length (m) Mean rating Model R = 1 m R = 4 m Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 15 / 17
38. Summary spatial sampling leads to additional wave fronts in WFS the repetitions are more critical for focused sources diffraction due to the length of the array causes wrong localization of synthesised sources binaural model is able to predict wrong localization due to diffraction binaural model gives a hint for which conditions the precedence effect has to be considered open question: coloration due to the additional wave fronts Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 16 / 17
39. Thank You! Questions? http://audio.qu.tu-berlin.de/ Wierstorf, Raake, Spors Perception of Synthesized Sound Fields 06/29/11 17 / 17