AES Paris 2016
Paper Session P6
P6 - Perception: Part 1
Sunday, June 5, 09:00 — 12:00 (Room 353)
Chair:
Dan Mapes-Riordan, Etymotic Research - Elk Grove Village, IL, USA; DMR Consulting - Evanston, IL, USA
P6-1 Perception of Low Frequency Transient Acoustic Phenomena in Small Rooms for Music—Lorenzo Rizzi, Suono e Vita - Acoustic Engineering - Lecco, Italy; Federico Ascari, Politecnico di Milano - Milan, Italy; Gabriele Ghelfi, Suono e Vita - Acoustic Engineering - Lecco, Italy; Michele Ferroni, Politecnico di Milano - Milan, Italy
Reducing the gap between analysis of low-frequency behavior of small rooms and actual perception, we introduce the importance of transient energetic phenomena besides classic FFT steady state analysis. After a frequency and temporal domain analysis of real-world impulse responses of critical listening rooms, headphone tests were performed. Results show that, for short musical sounds, a new curve called “Overshoot Response” can be more useful than classic frequency response regarding the level perception. Furthermore, the perceived loss of definition after the convolution with R.I.R. is correlated with decaying time and two metrics that were defined—“Room Slowness” and “Room Inertia.”
Convention Paper 9512 (Purchase now)
P6-2 The Reduction of Vertical Interchannel Crosstalk: The Analysis of Localization Thresholds for Musical Sources—Rory Wallis, University of Huddersfield - Huddersfield, West Yorkshire, UK; Hyunkook Lee, University of Huddersfield - Huddersfield, UK
Musical sources were presented to subjects as phantom images from vertically arranged stereophonic loudspeakers. Loudspeakers were arranged in two layers: “main” and “height.” Subjects reduced the amplitude of the height layer until the resultant phantom image matched the position of the same source presented from the lower loudspeaker alone; this was referred to as the “localization threshold.” Delays ranging from 0–10 ms were applied to the height layer. The localization threshold was only significantly affected by the ICTD. The median threshold for 0 ms was –9.5 dB, which was significantly lower than the –7 dB found for the stimuli in which the height layer was delayed. No evidence was found to support the existence of the precedence effect in the median plane.
Convention Paper 9513 (Purchase now)
P6-3 The Perception of Vertical Image Spread by Interchannel Decorrelation—Christopher Gribben, University of Huddersfield - Huddersfield, West Yorkshire, UK; Hyunkook Lee, University of Huddersfield - Huddersfield, UK
Subjective listening tests were conducted to assess the general perception of decorrelation in the vertical domain. Interchannel decorrelation was performed between a pair of loudspeakers in the median plane; one at ear level and the other elevated 30° above. The test stimuli consisted of decorrelated octave-band pink noise samples (63–8000 Hz), generated using three decorrelation techniques—each method featured three degrees of the interchannel cross-correlation coefficient (ICCC): 0.1, 0.4, and 0.7. Thirteen subjects participated in the experiment, using a pairwise comparison method to grade the sample with the greater perceived vertical image spread (VIS). Results suggest there is broadly little difference of overall VIS between decorrelation methods, and changes to vertical interchannel decorrelation appear to be better perceived in the upper-middle-frequencies.
[Also a poster—see session 12-16]
Convention Paper 9514 (Purchase now)
P6-4 Measurements to Determine the Ranking Accuracy of Perceptual Models—Andy Pearce, University of Surrey - Guildford, Surrey, UK; Tim Brookes, University of Surrey - Guildford, Surrey, UK; Russell Mason, University of Surrey - Guildford, Surrey, UK; Martin Dewhirst, University of Surrey - Guildford, Surrey, UK
Linear regression is commonly used in the audio industry to create objective measurement models that predict subjective data. For any model development, the measure used to evaluate the accuracy of the prediction is important. The most common of these assume a linear relationship between the subjective data and the prediction, though in the early stages of model development this is not always the case. Measures based on rank ordering (such as Spearman’s test), can alternatively be used. Spearman’s test, however, does not consider the variance of the subjective results. This paper presents a method of incorporating the subjective variance in the Spearman’s rank ordering test using Monte Carlo simulations and shows how this can be used to develop predictive models.
Convention Paper 9515 (Purchase now)
P6-5 Assessment of the Impact of Spatial Audiovisual Coherence on Source Unmasking—Julian Palacino, UBO - LabSTICC - Lorient, France; Mathieu Paquier, UBO - Brest, France; Vincent Koehl, UBO - Lab-STICC - Brest, France; Frédéric Changenet, Radio France - Paris, France; Etienne Corteel, Sonic Emotion Labs - Paris, France
The present study aims at evaluating the contribution of spatial audiovisual coherence for sound source unmasking for live music mixing. Sound engineers working with WFS technologies for live sound mixing have reported that their mixing methods have radically changed. Using conventional mixing methods, the audio spectrum is balanced in order to get each instrument intelligible inside the stereo mix. In contrast, when using WFS technologies, the source intelligibility can be achieved thanks to spatial audiovisual coherence and/or sound spatialization (and without using spectral modifications). The respective effects of spatial audiovisual coherence and sound spatialization should be perceptually evaluated. As a first step, the ability of naive and expert subjects to identify a spatialized mix was evaluated by a discrimination task. For this purpose, live performances (rock, jazz, and classic) were played back to subjects with and without stereoscopic video display and VBAP or WFS audio rendering. Two sound engineers realized the audio mixing for three pieces of music and for both audio technologies in the same room where the test have been carried out.
[Also a poster—see session P12-10]
Convention Paper 9516 (Purchase now)
P6-6 Auditory Perception of the Listening Position in Virtual Rooms Using Static and Dynamic Binaural Synthesis—Annika Neidhardt, Technische Universität Ilmenau - Ilmenau, Germany; Bernhard Fiedler, University of Technology Ilmenau - Ilmenau, Germany; Tobias Heinl, University of Technology Ilmenau - Ilmenau, Germany
Virtual auditory environments (VAEs) can be explored by controlling the position and orientation of an avatar and listening to the scene from its changing perspective. Reverberation is essential for immersion and plausibility as well as for externalization and the distance perception of the sound sources. These days, room simulation algorithms provide a high degree of realism for static and dynamic binaural reproduction. In this investigation, the ability of people to discriminate listening positions within a virtual room is studied. This is interesting to find out whether the state of the art room simulation algorithms are perceptually appropriate, but also to learn more about people’s capability of orientating themselves within a purely acoustical scene. New findings will help designing suitable VAEs.
Also a poster—see session P12-1]
Convention Paper 9517 (Purchase now)
