Novel approaches towards more realistic listening environments for experiments in complex acoustic scenes

Transcription

1 Novel approaches towards more realistic listening environments for experiments in complex acoustic scenes Janina Fels, Florian Pausch, Josefa Oberem, Ramona Bomhardt, Jan-Gerrit-Richter Teaching and Research Area Medical Acoustics Institute of Technical Acoustics RWTH Aachen University Germany

2 Motivation Current Practice / State-of-the-Art Simple reproduction Unrealistic test signals One-way treatment with several re-visits 2 of 23

3 Motivation Modern Soft- and Hardware Solutions for Experiments Audiovisual laboratory environment Advanced technical systems for immersive audiovisual reproduction Controlled laboratory situation 3 of 23

4 Motivation Research, Diagnosis & Rehabilitation using Complex Realistic Scenes Complex virtual scene Rendering of realistic scenes using Acoustic Virtual Reality methods Arbitrary research paradigms Multiple-way, efficient treatment & rehabilitation 5 of 23

5 Examples of Current Reproduction Systems Reproduction Technique Physically correct sound field reproduction Hardware requirements Flexibility in complex scenes Localization Drawbacks Binaural Technology Discrete loudspeakers Simple to advanced panning techniques / Stereo, VBAP, MDAP, Ambisonics ++ authentic for speech - (low) (medium/high) (medium/high) ++ + Tracking system and individual H(A)RTFs needed, authentic for speech only Only real sound sources and simulated reflections at loudspeaker positions possible Perception-based reproduction, possible discontinuities in virtual sound source movements, pronounced sweetspot area, coloration, not authentic Near-field compensated Higher-Order Ambisonics + + (medium/high) +++ o upper frequency limit (spatial aliasing), pronounced sweetspot area, coloration, not authentic Wave Field Synthesis o ++ (up to hundreds of loudspeakers) upper frequency limit (spatial aliasing), coloration, not authentic 6 of 23

6 Possible Steps for Validation of Virtual Acoustic Environments Objective Validation Calculation of room acoustic parameters Measurements on dummy heads (children and adults) with and without hearing aids Complex virtual scene Subjective Validation Spatial audio quality (immersion, plausibility, authenticity, coloration, localization, distance perception etc.) Perception Cognition (attention, etc.) Influencing factors Individual hearing aid, individual HRTF Reproduction system and environment (uncertainty, reproducibility) Experimental design and paradigms Cross-modal effects 7 of 23

7 Auralization Concept Goal Simulation of plausible acoustic scenes (including room acoustics) 8 of 23

8 Methodology Binaural Reproduction Real-time update of HRTFs / HARTFs based on real-world head position Highly reactive system: Low end-to-end latency Acoustic crosstalk cancellation (CTC) system with 4 loudspeakers Research hearing aids (RHA) controlled by a master hearing aid platform + CTC with 4 loudspeakers RHA Masiero & Vorländer, 2014; Grimm et al., of 23

9 From Children to Adults: HRTF as Directivity 6 Month Kindergarten Grownup Fels, J.; Buthmann, P. & Vorländer, M. (2004), ACTA ACUSTICA united with ACUSTICA 90(5), Fels, J. & Vorländer, M. (2009), ACTA ACUSTICA united with ACUSTICA 95(2), of 23

10 Methodology Head- & Hearing-aid-related Transfer Functions HRTFs & HARTFs measured from ITA dummy head with artificial ear Individualization based on individual anthropometric data Interaural time difference & frequency scaling Pre-calculated database covering 15 th, 50 th, & 85 th percentiles of children head dimensions Height Depth Width Bomhardt, R. & Fels, J. (2016) 'Audio Engineering Society Convention 140'. Bomhardt, R. & Fels, J. (2016), The Journal of the Acoustical Society of America 140(4), Bomhardt, R.; Lins, M. & Fels, J. (2016), Journal of the Audio Engineering Society 64(11), Fels, J. & Bomhardt, R. (2016), The Journal of the Acoustical Society of America 140(4), Fels, J.; Buthmann, P. & Vorländer, M. (2004), ACTA ACUSTICA united with ACUSTICA 90(5), Fels, J. & Vorländer, M. (2009), ACTA ACUSTICA united with ACUSTICA 95(2), of 23

11 Fast Individual HRTF Measurement Richter, J.-G.; Behler, G. & Fels, J. (2016), 'Audio Engineering Society Convention 140'. 12 of 23

12 Study 1: Speech perception by children in a real-time virtual acoustic environment with simulated hearing aids and room acoustics This project has received funding from the European Union s Seventh Framework Programme for research, technological development and demonstration under grant agreement no FP

13 Methodology Room Acoustics Simulation in RAVEN Room Acoustics for Virtual Environments, Schröder, 2011 Rectangular typical classroom of 270 m³ Low- vs. High-reverberation conditions: 0.4 vs. 1.1 s 14 of 23

14 Methodology Paradigm Eight test conditions tested within-subject Adaptive procedure to track 50% accuracy in sentence recognition (SRT) Pitch cue T T D D Spatial cue SRT T T SRT 2 reverberation times (0.4 s vs. 1.1 s) D D D D SRT SRT Cameron & Dillon (2007) Paradigm 15 of 23

15 Summary of Study 1 Real-time VAE set-up to be used throughout subsequent auditory training and post-tests with integration of simulated hearing aid signals individualized children HRTFs plausible room acoustics Experiments with children fitted with bilateral hearing aids SRT: Main effects of Location, Talker and Reverb RM: HL group gets lower spatial advantage RM: HL group gets lower total advantage (RM: HL group gains higher total advantage under higher reverberation time) Aspöck, L.; Pausch, F.; Vorländer, M. & Fels, J. (2015), Fortschritte der Akustik - DAGA 2015, Pausch, F.; Aspöck, L. & Fels, J. (2015), Fortschritte der Akustik - DAGA 2015, Pausch, F.; Peng, Z. E.; Aspöck, L. & Fels, J. (2016), HEAL HEaring Across the Lifespan. Pausch, F.; Peng, Z. E.; Aspöck, L. & Fels, J. (2016), 22nd International Congress on Acoustics, Buenos Aires, Argentina. Peng, Z. E.; Pausch, F.; Aspöck, L. & Fels, J. (2016), AudiologyNOW! 2016, Phoenix, Arizona. 16 of 23

16 Study 2: Examining auditory selective attention in realistic, natural environments

17 Intentional Switching of Auditory Selective Attention Hearing research utilizing paradigms taken from Psychology Cooperation with Institute of Psychology, RWTH Aachen University [Koch, Lawo, Fels, Vorländer (2011), J Exp Psychol-Hum Percept Perform] [Lawo, Fels, Oberem, Koch (2014), Q J Exp Psychol] [Oberem, Lawo, Koch, Fels (2014), Acta Acust united Ac] 18 of 23 Self-portrayal Institute of Technical Acoustics RWTH Aachen University Medical Acoustics Group October 2016

18 Definition of Transition of Target - Binaural Repetition of Target s Position Switch of Target s Position 19 of 23

19 Definition of Congruency - Binaural Congruent: Digits are both smaller than 5, or both greater than 5 (2 < 5 and 4 < 5). Incongruent: One digit is smaller than 5 and the other is greater than 5 (3 < 5 and 7 > 5). 20 of 23

20 Results RT - Binaural Oberem, J., Lawo, V., Koch, I. & Fels, J. (2014). Intentional switching in auditory selective attention: Exploring different binaural reproduction methods in an anechoic chamber. Acta Acustica, 100, of 23

21 Motivation = Outlook Research, Diagnosis & Rehabilitation using Complex Realistic Scenes Complex virtual scene Rendering of realistic scenes using Acoustic Virtual Reality methods Arbitrary research paradigms Multiple-way, efficient treatment & rehabilitation 22 of 23

22 Thank you for your attention Janina Fels, Florian Pausch, Josefa Oberem, Ramona Bomhardt, Jan-Gerrit-Richter Teaching and Research Area for Medical Acoustics Institute of Technical Acoustics RWTH Aachen University Kopernikusstraße Aachen Germany Janina.Fels@akustik.rwth-aachen.de