Binaural Technology: Method or Subject of Perceptual Audio Research?

Invited talk given at the IRCAM (Institut de Recherche et Coordination Acoustique/Musique), Paris, FR, 30.1.2015

Transcript

1. 1 Fachgebiet Audiokommunikation Audio Communication Group Fachgebiet Audiokommunikation Audio Communication Group Binaural Technology: Method or Subject of Perceptual Audio Research? Alexander Lindau, PhD January 30th, 2015 IRCAM, Paris
2. 2 Fachgebiet Audiokommunikation Audio Communication Group Audio Communication Group at TU Berlin (www.ak.tu-berlin.de) Research Teaching Arts Acoustics and Signal Processing Music Psychology Musicology
3. 3 Fachgebiet Audiokommunikation Audio Communication Group Recording and reproduction of binaural signals and spatial sound fields Audio Communication Group – Acoustics Team
4. 4 Fachgebiet Audiokommunikation Audio Communication Group STARGATE: 36-Channel loudspeaker array for fast individual HRTF measurements Audio Communication Group – Acoustics Team
5. 5 Fachgebiet Audiokommunikation Audio Communication Group Loudspeaker-based spatial sound field reproduction: World’s largest 832-channel WFS-Array, A 2nd 256-channel WFS-Array in a studio and a 22.2. Ambisonics-Array Audio Communication Group – Acoustics Team
6. 6 Fachgebiet Audiokommunikation Audio Communication Group Audio Communication Group – Acoustics Team MediaLab CAVE: 180° x 60° stereoscopic projection and binaural synthesis
7. 7 Fachgebiet Audiokommunikation Audio Communication Group  Prof. Dr. Stefan Weinzierl  Clemens Büttner  Zora Schärer  Dr. Alexander Lindau Research Projects  Simulation und Evaluation of Acoustic Environments (SEACEN, DFG FOR 1557)  Evaluation of Virtual Acoustic Environments (DFG, WE 4057/3-1)  Room Acoustic and Musical Performance (DFG, WE 4057/9-1)  Room Acoustics in the 16th Century Theaters (DFG, WE 4057/6-1)  Sound Field Synthesis for Line Array Public Address Systems (BMWi–ZIM/KF)  Fabian Brinkmann  Vera Erbes  Michael Horn  Florian Straube Research Group on (Virtual) Room and Musical Acoustics
8. 8 Fachgebiet Audiokommunikation Audio Communication Group SEACEN – Research Groups and Objectives Principal Investigator Subproject Title Research Area Modelling Recording Reproduction Evaluation P1 Vorländer / de Vries 3D room acoustics modelling X P2 Vorländer Determination of boundary conditions by inverse modelling of room acoustics X P3 Rafaely Measurement, processing and modelling of natural acoustic environments X X P4 Brandenburg / Brix / Sporer Psychoacoustic analysis and spatial coding of microphone array signals X X P5 Spors Signal processing for reproduction of room acoustics X X X P6 Weinzierl Evaluation of virtual acoustic environments X X P7 van de Par Models of room acoustical perception X P8 Vorländer Determination of the measurement and simulation uncertainty of room acoustical quantities X X P9 Maempel Audio-visual perception of acoustical environments X
9. 9 Fachgebiet Audiokommunikation Audio Communication Group SEACEN – Major Research Objectives … establish a Ground truth for Room acoustical Analysis and Perception (GRAP) based on a database of real and virtual acoustical environments and corresponding perceptual attributes, … establish a Ground truth for Room Acoustical Simulation (GRAS) with precise geometrical descriptions and precise boundary conditions, … conduct a Round Robin on Auralization based on physical and perceptual measures of quality for room acoustical simulation developed in SEACEN.
10. 10 Fachgebiet Audiokommunikation Audio Communication Group Talk’s Overview Binaural Technology – A Universal Perceptual Evaluation Method for Spatial Audio? BT - What is it? What makes it so universal? Pros & Cons of in simu evaluation. Dynamic Binaural Synthesis Technology. First perceptual assessments. Improvements and current state of the art. Perceptual Evaluation of Spatial Audio Technologies Plausibility. Authenticity. Spatial Audio Quality Inventory (SAQI). Challenges of a Binaural-Domain-Only Evaluation of Spatial Audio Profiling of individual and non-individual binaural synthesis. Challenges of in simu audio evaluation.
11. 11 Fachgebiet Audiokommunikation Audio Communication Group [1] Møller, H. (1992): "Fundamentals of Binaural Technology", in: Applied Acoustics, Vol. 36, No. 3-4, pp. 171-218 Binaural Technology – What is it?
12. 12 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation?
13. 13 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Flexibility Auralizations of measured sound fields obtained from  Dummy head recordings,  Binaural impulse response measurements, and  Microphone array recordings.
14. 14 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Flexibility Auralizations of simulated sound fields obtained from  Analytic,  Geometric or  Stochastic approaches. © S. Weinzierl, TUB © http://www.ise.ncsu.edu © cybernet.co.jp
15. 15 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Flexibility Auralizations of spatial audio reproduction techniques, such as  Stereophonic,  VBAP,  Ambisonics,  HOA, or  WFS setups. [1] Nahas, J. (2011): Simulation of a sound field reproduction approach for an innovative musical venue (III). Simulation of array-based sound field synthesis methods. Diploma thesis. RWTH Aachen & TU Berlin
16. 16 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Flexibility Binaural domain allows for convenient variation of  Room acoustics,  Source characteristics,  Receiver characteristics,  Geometrical arrangements,  Audio content. [1] Nahas, J. (2011): Simulation of a sound field reproduction approach for an innovative musical venue (III). Simulation of array-based sound field synthesis methods. Diploma thesis. RWTH Aachen & TU Berlin
17. 17 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Limited technical requirements  Software,  Hardware,  Space. © S. Roos, TU Berlin
18. 18 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Efficiency  Independence from simulated facilities/locations,  Repeated measures (within subject) studies with  Instantaneous auditive comparisons. © S. Roos, TU Berlin
19. 19 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? Potential for perceptual transparency  Real (measured) sound fields,  Full individualization of all binaural signal cues,  Full frequency compensation,  Seamless spatial representation, and  imperceptible latency towards user interaction. © F. Brinkmann, TU Berlin
20. 20 Fachgebiet Audiokommunikation Audio Communication Group Why use the Binaural Domain for Spatial Audio Evaluation? High internal validity  Convenient control of disturbing influences  De-confounding from specific characteristics of the simulated situation  Acoustic environment and geometrical arrangement,  Visual impression,  Haptics,  Smell,  Interface appearance and usability,  Social context,  Wearing comfort,  … © M. Horn, TU Berlin
21. 21 Fachgebiet Audiokommunikation Audio Communication Group Limitations of Binaural Domain Evaluation Complex stimulus production  Advanced academic tools for measurement/auralization  Expert knowledge required  Simulation of non-technical sound sources still a challenge Relief from  Acoustic simulation programs (EASE, ODEON, CATT Acoustic)  Public HRIR/BRIR databases  Public measurement software: ITA Toolbox (RWTH Aachen)  Public sound field analysis/synthesis tools: SOFiA-Toolbox (TU Cologne), SSR & SFS-Toolbox (TU Rostock), Wonder (TU Berlin), AmibX-Suite (Graz)  Cooperation with commercial developers (IOSONO, sonic emotion, IRCAM)
22. 22 Fachgebiet Audiokommunikation Audio Communication Group Limitations of Binaural Domain Evaluation Full perceptual transparency still a challenge  May be tolerable in listening tests involving ‘relative’ ratings  May compromise listening test involving ‘absolute’ ratings Relief from  Physical evaluation: Compare error measures to JNDs  Perceptual evaluation: Assessment of plausibility [1] and authenticity [2], multivariate sensory profiling [3], [4] [1] Lindau, A.; Weinzierl, S. (2012): “Assessing the Plausibility of Virtual Acoustic Environments”, in: Acta Acustica united with Acustica, 98(5), S. 804-810 [2] Brinkmann, F.; Lindau, A.; Vrhovnik, M.; Weinzierl, S. (2014): “Assessing the Authenticity of Individual Dynamic Binaural Synthesis”, in: Proc. of the EAA Joint Auralization and Ambisonics Symposium, Berlin, S. 62-68 [3] Silzle, Andreas (2007): "Quality Taxonomies for Auditory Virtual Environments", in: Proc. of the 122nd AES Convention. Vienna, preprint no. 6993 [4] Lindau, Alexander; Brinkmann, Fabian; Weinzierl, Stefan (2014): "Sensory Profiling of Individual and Non-individual Dynamic Binaural Synthesis Using the Spatial Audio Quality Inventory", in: Proc. of the EAA Forum Acusticum 2014. Krakow (PL)
23. 23 Fachgebiet Audiokommunikation Audio Communication Group Limitations of Binaural Domain Evaluation Reduced external validity  Auditory impression more than just sound field differences  Intermodal influences may play a role, too  Vestibular Cues [1]  Visual Cues [2], [3]  Situation-specific, sociological, emotional, or task-specific differences [4] [1] Kern, Harald; Lepa, Steffen: Die ‚Techno-Schwelle‘: Zur Bedeutsamkeit von Lautsprecherwiedergabe und Knochenleitung für die vestibulare Wirkung lauter Bassklänge im EDM-Clubkontext. In: DEGA (Hrsg.): DAGA 2014 – Fortschritte der Akustik, Berlin 2014 [2] Maempel, Hans-Joachim; Jentsch, Matthias: Auditory and Visual Contribution to Egocentric Distance and Room Size Perception". In: Building Acoustics, 20, 2013, S. 383-402. [3] Werner, Stephan; Siegel, André (2011): "Effects of binaural auralization via headphones on the perception of acoustic scenes", in: Proc. of the 3rd International Symposium on Auditory and Audiological Research (ISAAR). Nyborg, Denmark, pp. 215-222 [4] Lindau, Alexander (2010): "Zu den Dimensionen des Unterschied live aufgeführter und reproduzierter Musik: Ergebnisse einer qualitativ/quantitativen Umfragestudie", in: Fortschritte der Akustik: Tagungsband d. 36. DAGA. Berlin, pp. 609-610 ?
24. 24 Fachgebiet Audiokommunikation Audio Communication Group Limitations of Binaural Domain Evaluation Relief from  (If possible) Integration of real stimuli into in simu listening tests  Replication studies in real world scenarios [1]  Triangulation with field studies  Treatment checks: test for placebo effects [2] -0,5 -0,25 0 0,25 0,5 Headphones Home-Stereo (binaural) Concert Hall (binaural) Perceived Spatial Presence (estim. group means and std errors) expec. of high spatial quality no instruction [2] Lindau, Alexander; Lepa, Steffen (2014): "Dynamische Binauralsynthese - ein Verfahren der virtuellen Akustik als Ansatz zur Untersuchung technologiebezogener Hypothesen im Rahmen medienpsychologischer Rezeptionsexperimente", in: Tagungsband der Jahrestagung 2013 der Fachgruppe Methoden der DGPuK, Köln: Halem Figure from [1]: (Placebo) effect of a quality-expectancy-instruction on the perceived spatial presence [1] Wierstorf, Hagen; Spors, Sascha; Raake, Alexander (2012): "Perception and Evaluation of Sound Fields", in: Proc. of the 59th Open Seminar on Acoustics (OSA). Boszkowo (PL)
25. 25 Fachgebiet Audiokommunikation Audio Communication Group A First Summary Binaural-domain assessment of spatialization is a  Flexible,  Convenient,  Efficient,  (Potentially) Perceptually transparent, and  Internally valid evaluation method. However, its widespread application still suffers from  Complex stimulus production,  (Sometimes) Limited perceptual transparency, and  Limited external validity.
26. 26 Fachgebiet Audiokommunikation Audio Communication Group Overview Binaural Technology – A Universal Perceptual Evaluation Method for Spatial Audio? BT - What is it? What makes it so universal? Pros & Cons of in simu evaluation. Dynamic Binaural Synthesis Technology. First perceptual assessments. Improvements and current state of the art. Perceptual Evaluation of Spatial Audio Technologies Plausibility. Authenticity. Spatial Audio Quality Inventory (SAQI). Challenges of a Binaural-Domain-Only Evaluation of Spatial Audio Profiling of individual and non-individual binaural synthesis. Challenges of in simu audio evaluation.
27. 27 Fachgebiet Audiokommunikation Audio Communication Group head tracking Playback BRIR- Measurement Fast convolu- tion Anechoic audio BRIR- dataset Data-based Dynamic Binaural Synthesis (DDBS)
28. 28 Fachgebiet Audiokommunikation Audio Communication Group Initial Perceptual Assessment of DDBS, [1]  AB comparison of simulation and reality  Qualitative differences elicited (N = 35) Results*: Coloration (5x) Localization (4x) Latency (2x) Reverberant level (2x) Overall loudness (2x) … *from ‘significant recognizers of the simulation’ only, (N = 8) [1] Lindau, Alexander; Hohn, Torben; Weinzierl, Stefan (2007): "Binaural resynthesis for comparative studies of acoustical environments", in: Proc. of the 122nd AES Convention. Vienna, preprint no. 7032
29. 29 Fachgebiet Audiokommunikation Audio Communication Group Minimum required BRIR resolution Maximally tolerable latency Optimum headphone compensation Minimally audible BRIR crossfading Optimum binaural headphones Efficient rendering of late reverberation Individualization of ITD cues Dynamic Binaural Synthesis – State of the Art
30. 30 Fachgebiet Audiokommunikation Audio Communication Group Minimum required BRIR resolution Maximally tolerable latency Optimum headphone compensation Minimally audible BRIR crossfading Optimum binaural headphones Efficient rendering of late reverberation Individualization of ITD cues Dynamic Binaural Synthesis – State of the Art < 52 ms ΔYaw Δ Pitch Δ Roll ≤ 2° 1° 1° High pass regularized LMS inversion based on recording head’s HpTF Onset-detection-based removal of initial delay Extra-aural, full range, FIR pre-equalized, low noise design Estimation of Perceptual Mixing Time, time-invariant late reverberation Individual re-scaling of ITD through real time SRC
31. 31 Fachgebiet Audiokommunikation Audio Communication Group Minimum required BRIR resolution Maximally tolerable latency Optimum headphone compensation Minimally audible BRIR crossfading Optimum binaural headphones Efficient rendering of late reverberation Individualization of ITD cues Dynamic Binaural Synthesis – State of the Art < 52 ms ΔYaw Δ Pitch Δ Roll ≤ 2° 1° 1° High pass regularized LMS inversion based on recording head’s HpTF Onset-detection-based removal of initial delay Extra-aural, full range, FIR pre-equalized, low noise design Estimation of Perceptual Mixing Time, time-invariant late reverberation Individual re-scaling of ITD through real time SRC Lindau, Alexander (2014): Binaural Resynthesis of Acoustical Environments. Technology and Perceptual Evaluation. PhD thesis, TU Berlin Open access: ak.tu-berlin.de/alindau Demos: ak.tu-berlin.de Lindau, Alexander (2014): Binaural Resynthesis of Acoustical Environments. Technology and Perceptual Evaluation. PhD thesis, TU Berlin Open access: ak.tu-berlin.de/alindau Demos: ak.tu-berlin.de
32. 32 Fachgebiet Audiokommunikation Audio Communication Group Overview Binaural Technology – A Universal Perceptual Evaluation Method for Spatial Audio? BT - What is it? What makes it so universal? Pros & Cons of in simu evaluation. Dynamic Binaural Synthesis Technology. First perceptual assessments. Improvements and current state of the art. Perceptual Evaluation of Spatial Audio Technologies Plausibility. Authenticity. Spatial Audio Quality Inventory (SAQI). Challenges of a Binaural-Domain-Only Evaluation of Spatial Audio Profiling of individual and non-individual binaural synthesis. Challenges of in simu audio evaluation.
33. 33 Fachgebiet Audiokommunikation Audio Communication Group Perceptual Evaluation of Spatial Audio Technologies (1) Assessments of univariate auditive qualities  Localization performance,  Number of front-back reversals,  Frequencies of in-head localization (2) Assessments of overall measures of auditive fidelity  Difference, MOS (Liking), Impairment, …  Presence, Immersion,  Authenticity, Plausibility (3) Assessments of multivariate auditive quality  “Quality Features” (model-based VAEs)  Spatial Audio Quality Inventory Møller, 1997 ITU Silzle, 2008
34. 34 Fachgebiet Audiokommunikation Audio Communication Group Testing the Plausibility of a Simulation Aim: Assessment of perceived realism in case no explicit reference given Plausible: „A simulation in agreement with the expectation of a corresponding real event.“ Test: Yes/No-Task Evaluation: Signal Detection Theory, t-tests Lindau, A.; Weinzierl, S. (2012): “Assessing the Plausibility of Virtual Acoustic Environments”, in: Acta Acustica united with Acustica, 98(5), S. 804-810
35. 35 Fachgebiet Audiokommunikation Audio Communication Group stairs stairs balcony stalls FABIAN 9.5 m 13.4 m Was this a simulated loudspeaker? Stage Testing the Plausibility of a Simulation Yes No Lindau, A.; Weinzierl, S. (2012): “Assessing the Plausibility of Virtual Acoustic Environments”, in: Acta Acustica united with Acustica, 98(5), S. 804-810
36. 36 Fachgebiet Audiokommunikation Audio Communication Group (A) Initial Binaural Simulation Simulation detected (“Yes”) Loudspeaker detected (“No”) Σ Simulated loudspeaker 100 % Real loudspeaker 100 % (B) Improved Binaural Simulation Simulation detected (“Yes”) Loudspeaker detected (“No”) Σ Simulated loudspeaker pHIT : 35.33 % pMiss : 64.67 % 100 % Real loudspeaker pFA : 33.54 % pCR : 66.46 % 100 % N = 11 N = 11 pHIT : 51.06 % pFA : 39.88 % pMiss : 48.94 % pCR : 60.12 % Testing the Plausibility of a Simulation Lindau, A.; Weinzierl, S. (2012): “Assessing the Plausibility of Virtual Acoustic Environments”, in: Acta Acustica united with Acustica, 98(5), S. 804-810
37. 37 Fachgebiet Audiokommunikation Audio Communication Group (A) Initial Binaural Simulation Simulation detected (“Yes”) Loudspeaker detected (“No”) Σ Simulated loudspeaker 100 % Real loudspeaker 100 % (B) Improved Binaural Simulation Simulation detected (“Yes”) Loudspeaker detected (“No”) Σ Simulated loudspeaker pHIT : 35.33 % pMiss : 64.67 % 100 % Real loudspeaker pFA : 33.54 % pCR : 66.46 % 100 % N = 11 N = 11 pHIT : 51.06 % pFA : 39.88 % pMiss : 48.94 % pCR : 60.12 % Testing the Plausibility of a Simulation Lindau, A.; Weinzierl, S. (2012): “Assessing the Plausibility of Virtual Acoustic Environments”, in: Acta Acustica united with Acustica, 98(5), S. 804-810
38. 38 Fachgebiet Audiokommunikation Audio Communication Group Testing the Authenticity of a Simulation Aim: Assessment of with respect to a given reference (e.g. reality) Authentic: „A simulation that can not be distinguished from a given reference stimulus.“ Test: ABX-Task Evaluation: Detection rates, testable using binomial distribution Brinkmann, F.; Lindau, A.; Vrhovnik, M.; Weinzierl, S. (2014): “Assessing the Authenticity of Individual Dynamic Binaural Synthesis”, in: Proc. of the EAA Joint Auralization and Ambisonics Symposium, Berlin, pp. 62-68
39. 39 Fachgebiet Audiokommunikation Audio Communication Group N = 9 Listening test setup Results Spectral difference between real and simulated ear signals Testing the Authenticity of a Simulation Brinkmann, F.; Lindau, A.; Vrhovnik, M.; Weinzierl, S. (2014): “Assessing the Authenticity of Individual Dynamic Binaural Synthesis”, in: Proc. of the EAA Joint Auralization and Ambisonics Symposium, Berlin, pp. 62-68
40. 40 Fachgebiet Audiokommunikation Audio Communication Group Sensory Profiling of Spatial Audio Technologies – The Spatial Audio Quality Inventory (SAQI) Lindau, A. et al. (2014): “A Spatial Audio Quality Inventory”, in: Acta Acustica united with Acustica, 100(5): 984–99 Moderated group discussion Observer group
41. 41 Fachgebiet Audiokommunikation Audio Communication Group Category Auditory Quality Tone Color (8) Tone color bright-dark, High-/Mid-/Low-frequency tone color, Sharpness, Roughness*, Comb filter coloration*, Metallic tone color Tonalness (3) Tonalness, Pitch, Doppler effect Geometry (10) Horizontal/Vertical direction, Front-back position, Distance, Depth, Width, Height, Externalization, Localizability, Spatial disintegration Room (3) Level of reverberation, Duration of reverberation, Envelopment by reverberation Time behavior (7) Pre-/Post-echoes, Temporal disintegration, Crispness, Speed, Sequence of events, Responsiveness Dynamics (3) Loudness, Dynamic range, Dynamic compression effects* Artifacts (7) Pitched/Impulsive/Noise-like artifact, Alien source, Ghost source, Distortion, Tactile vibration General (7) (Overall) Difference, (Overall) Clarity, Speech intelligibility, Naturalness, (Spatial) Presence, Degree-of-Liking, Other * Illustrative audio examples have been created. SAQI: What’s inside the box?
42. 42 Fachgebiet Audiokommunikation Audio Communication Group Category Auditory Quality Tone Color (8) Tone color bright-dark, High-/Mid-/Low-frequency tone color, Sharpness, Roughness*, Comb filter coloration*, Metallic tone color Tonalness (3) Tonalness, Pitch, Doppler effect Geometry (10) Horizontal/Vertical direction, Front-back position, Distance, Depth, Width, Height, Externalization, Localizability, Spatial disintegration Room (3) Level of reverberation, Duration of reverberation, Envelopment by reverberation Time behavior (7) Pre-/Post-echoes, Temporal disintegration, Crispness, Speed, Sequence of events, Responsiveness Dynamics (3) Loudness, Dynamic range, Dynamic compression effects* Artifacts (7) Pitched/Impulsive/Noise-like artifact, Alien source, Ghost source, Distortion, Tactile vibration General (7) (Overall) Difference, (Overall) Clarity, Speech intelligibility, Naturalness, (Spatial) Presence, Degree-of-Liking, Other * Illustrative audio examples have been created. SAQI: What’s inside the box? SAQI Test Manual DOI 10.14279/depositonce-1 Use with free whisPER listening test software DOI 10.14279/depositonce-31
43. 43 Fachgebiet Audiokommunikation Audio Communication Group Overview Binaural Technology – A Universal Perceptual Evaluation Method for Spatial Audio? BT - What is it? What makes it so universal? Pros & Cons of in simu evaluation. Dynamic Binaural Synthesis Technology. First perceptual assessments. Improvements and current state of the art. Perceptual Evaluation of Spatial Audio Technologies Plausibility. Authenticity. Spatial Audio Quality Inventory (SAQI). Challenges of a Binaural-Domain-Only Evaluation of Spatial Audio Profiling of individual and non-individual binaural synthesis. Challenges of in simu audio evaluation.
44. 44 Fachgebiet Audiokommunikation Audio Communication Group Sensory Profiling of Individual and Non-individual DDBS Aim Qualify and quantify remaining deviations of DDBS from acoustic reality in a comparative listening test  Nine subjects compared individual & non-individual simulations to reality  Questionnaire created from SAQI1  Free Matlab® listening test toolbox WhisPER2 1 Lindau, A. et al. (2014): “A Spatial Audio Quality Inventory”, in: Acta Acustica united with Acustica, 100(5): 984–994 2 DOI: 10.14279/depositonce-31
45. 45 Fachgebiet Audiokommunikation Audio Communication Group Individual DDBS Non-individual DDBS Sensory Profiling of Individual and Non-individual DDBS Lindau, A. Brinkmann, F.; Weinzierl, S. (2014): "Sensory Profiling of Individual and Non-individual Dynamic Binaural Synthesis Using the Spatial Audio Quality Inventory", in: Proc. of the EAA Forum Acusticum 2014. Krakow (PL)
46. 46 Fachgebiet Audiokommunikation Audio Communication Group Tone Color Tone Color Tonalness Tonalness Geometry Geometry Room Room Time Time Artifacts Artifacts Dynamics Dynamics General General N = 9
47. 47 Fachgebiet Audiokommunikation Audio Communication Group Results  Wilcoxon Signed-Rank Test on “Difference”, p .012  Only little differences for some SAQI qualities  Inter-individual variation, but no overall difference  Inter-individual variation & overall differences
48. 48 Fachgebiet Audiokommunikation Audio Communication Group Conclusions Non-individual binaural simulations  Potentially plausible  Further improvement by spectral individualization  Potentially acceptable for conduction in simu relative assessments  Remaining artifacts may compromise in simu absolute assessments (but are known now) Individual binaural simulations  Potentially authentic  Future improvements unlikely (limits of accuracy)  Data-based approach generally impractical  Potentially allows fully transparent in simu assessments  Limitations of external validity remain
49. 49 Fachgebiet Audiokommunikation Audio Communication Group Future Work Use generic spatialization methods which allow for post hoc individualization © Bernschütz © Jin 2014 Opto-numerical HRTF synthesis MIMO – sound field recording techniques
50. 50 Fachgebiet Audiokommunikation Audio Communication Group Thank you for your attention! alexander.lindau@tu-berlin.de