AES Berlin 2017
Paper Session P01
P01 - Spatial Audio—Binaural 1
Saturday, May 20, 09:30 — 12:00 (Salon 1 Moscow)
David Griesinger (Chair)
P01-01 Perceptual Evaluation of Synthetic Early Binaural Room Impulse Responses Based on a Parametric Model
Philipp Stade (Presenting Author), Johannes M. Arend (Author), Christoph Pörschmann (Author)
Binaural synthesis is often applied in the field of spatial audio to create a virtual acoustic environment using binaural room impulse responses (BRIRs). In the same area of research, spherical microphone arrays are gaining importance and allow for a spatio-temporal analysis. We present a new approach to describe the acoustical environment by a parametric model using sound field analysis. Combining spherical head related impulse responses (HRIRs) with this description, early BRIRs are synthesized and compared to the measured counterparts in a perceptual evaluation. The listening experiment revealed adequate performance of the approach, almost independently from room and test signal. Surprisingly the synthesis of direct sound and only diffuse reverberation yielded nearly the same results as for the entire parametric model.
Convention Paper 9688
P01-02 Implementation and Evaluation of a Low-Cost Headtracker for Binaural Synthesis
Michael Romanov (Presenting Author), Paul Berghold (Author), Matthias Frank (Author), Daniel Rudrich (Author), Markus Zaunschirm (Author), Franz Zotter (Author)
Human auditory localization strongly relies on head movements. Thus, for plausible perception of virtual acoustic scenes the incorporation of head movements is mandatory. This is achieved via loudspeaker playback as a listener can move the head relatively to the scene. When using binaural synthesis the head movements need to be tracked and the scene needs to be rotated accordingly to achieve a stable perception of the acoustic scene. We present a low-cost, plug-and-play device (MrHeadTracker ) to facilitate head-tracking based on the Arduino platform and the BNO055 sensor. Its performance is compared against another low-cost device (GY-85) and an optical tracking system (Optitrack Flex 13). The proposed MrHeadTracker outperforms the GY-85 device in terms of accuracy and latency and yields comparable results to the optical tracking system.
Convention Paper 9689
P01-03 Influence of Head Tracking on the Externalization of Auditory Events at Divergence between Synthesized and Listening Room Using a Binaural Headphone System
Stephan Werner (Presenting Author), Georg Götz (Author), Florian Klein (Author)
This contribution presents an investigation on the influence of head tracking on the perceived externalization of auditory events using a binaural headphone system. Recordings of individual binaural room impulse responses of a five channel loudspeaker setup in two acoustic different rooms are conducted. Test persons are divided into two groups, while for the first group the listening and synthesized rooms do match (convergence), they do not for the second group (divergence). Moving the head during listening is mandatory and controlled by the test procedure. Perceived externalization of auditory events is used as a quality feature. The analysis of the ratings confirms that head tracking increases perceived externalization. Furthermore, the room divergence effect can be confirmed. Significantly lower externalization is observed if a divergence between the resynthesized and listening room occurs. However, the results clearly show that the benefit of head tracking on externalization does not overcome the room divergence effect.
Convention Paper 9690
P01-04 Laboratory Reproduction of Binaural Concert Hall Measurements through Individual Headphone Equalization at the Eardrum
David Griesinger (Presenting Author)
Progress relating measurements to perception of acoustics of all kinds has been stymied by the difficulty of accurately reproducing a room sound in a laboratory. Spatial aliasing above 1000 Hz, where most information in speech and music resides, severely limits the ability of multiple loudspeaker systems to reproduce proximity. We have developed a simple method of equalizing headphones that accurately reproduces the timbre of a frontal sound source at the eardrums. Combining individual headphone playback with Tapio Lokki’s anechoic recordings makes hall research inexpensive, rapid, and accurate. We can easily test the effects of early reflections and other spatial properties. We find the earliest reflections, whether medial or lateral, are almost always detrimental. Examples from real halls will be presented.
Convention Paper 9691
P01-05 Approaching Immersive 3D Audio Broadcast Streams of Live Performances
Giordano Jacuzzi (Presenting Author), Sofia Brazzola (Author), Johannes Kares (Author)
This paper explores the requirements and best practices of recording, mixing, and streaming broadcasts of live music performances in binaural and ambisonics formats. We outline the optimal workflows for incorporating and executing 3D audio streams with existing in-house infrastructure, as determined from our experience gathered testing and broadcasting public concert events in partnership with Moods jazz club in Zurich, Switzerland, and Vienna State Opera in Vienna, Austria. In addition, this paper discusses the current technological barriers for immersive audio content creation and consumption, areas for growth and improvement, and future projections for 3D immersive audio technology.
Convention Paper 9692