Monday, May 22, 09:00 — 12:30
Russell Mason (Chair)
P14-01 Evaluation of Auditory Events with Projected Sound Sources Using Perceptual Attributes
Tom Wühle (Presenting Author), M. Ercan Altinsoy (Author), Sebastian Merchel (Author)
The main aim of the projection of sound sources is to change the perceived direction of the auditory event from the direction of the real source to the direction of the projected source. However, the focusing capabilities of projecting sound sources are physically limited. Therefore, the perception of the listener is not only influenced by the projected sound but also by the sound that is directly radiated from the real source. In a scenario with projected sound sources a complex mixture of perceptual attributes change besides the direction of the auditory event. The present study describes this perceptual processes and investigates some of those attributes.
Convention Paper 9753
P14-02 The Evaluation of the Effect of Sound Directionality in Horizontal Plane on the Human Auditory Distance Perception in a Large Reverberant Room
Tahereh Afghah (Presenting Author), Andrew Allen (Author), Aravindan Joseph Benjamin (Author), Peter Otto (Author)
An evaluation of sound localization effect on the auditory distance estimation in a user study is presented. Binaural Room Impulse Responses of 60 positions were recorded in a reverberant space using a dummy head. The recordings were evaluated by the users in a headphone-based listening test to analyze the listeners’ ability to perceive the distance with and without prior knowledge of direction of origin. When known, the distance estimation accuracy in left and right sides of the head in near field (2m, 4m) was improved and at some angles saw a significant improvement. However, known direction did not assist the users in determining the larger distance levels (6m, 8m, 10m). No improvements were seen in the front and back sides for all directions.
Convention Paper 9754
P14-03 Improvement of the Reporting Method for Closed-Loop Human Localization Experiments
Fiete Winter (Presenting Author), Sascha Spors (Author), Hagen Wierstorf (Author)
Sound Field Synthesis reproduces a desired sound field within an extended listening area using up to hundreds of loudspeakers. The perceptual evaluation of such methods is challenging, as many degrees of freedom have to be considered. Binaural Synthesis simulating the loudspeakers over headphones is an effective tool for the evaluation. A prior study has investigated whether non-individual anechoic binaural synthesis is perceptually transparent enough to evaluate human localization in sound field synthesis. With the used apparatus, an undershoot for lateral sound sources was observed for real loudspeakers and their binaural simulation. This paper reassesses human localization for the mentioned technique using a slightly modified setup. The results show that the localization error decreased and no undershoot was observed.
Convention Paper 9755
P14-04 Investigations on Perceptual Phenomena of the Precedence Effect Using a Bessel Sequence
Florian Wendt (Presenting Author)
The precedence effect is typically investigated by presenting two instances of a sound with delay in between. Respective studies found various phenomena indicating that in human auditory localization the contribution of the first sound instance often prevails over a later sound or an acoustic reflection. In reverberant environments, the direct sound is typically followed by more than one reflection. Nevertheless, only little is known about the contribution of multiple reflections on the precedence effect. Understandably, a free number of sound instances increases the number of thinkable conditions drastically and an exhaustive systematic investigation appears infeasible. Directionally distributed impulses weighted by a Bessel sequence offer a neat set of free parameters. We chose this scheme to gain quantitative insights into the influence of multiple reflections on the precedence effect. Our study covers the transient precedence effect, the ongoing precedence effect, and the onset capture effect, which we investigate using sounds of different envelope, frequency range, angular and temporal spread.
Convention Paper 9756
P14-05 Just Noticeable Difference in Apparent Source Width Depending on the Direction of a Single Reflection
Dale Johnson (Presenting Author), Hyunkook Lee (Author)
An investigation on the just noticeable difference in angle of a single reflection in terms of apparent source width was performed using a staircase method to obtain two, single reflection angles between 0° and 180°. In the presence of a direct sound, subjects compared the apparent source width produced by a single 90° reference reflection, and a single test reflection ranging between 0° to 90° and 0° to 180° for each threshold. Subjects repeated this test for four delay times of 5 ms, 10 ms, 20 ms, and 30 ms. Reflection angles were found to be approximately 40° and 130° and, however, do not appear to vary with delay time. This implies that human hearing is not sensitive to changes in reflection angle in terms of apparent source width between the threshold angles.
Convention Paper 9757
P14-06 Modeling Horizontal Audio-Visual Coherence with the Psychometric Function
Hanne Stenzel (Presenting Author), Jon Francombe (Author), Philip J. B. Jackson (Author)
Studies on perceived audio-visual spatial coherence in the literature have commonly employed continuous judgment scales. This method requires listeners to detect and to quantify their perception of a given feature and is a difficult task, particularly for untrained listeners. An alternative method is the quantification of a percept by conducting a simple forced choice test with subsequent modeling of the psychometric function. An experiment to validate this alternative method for the perception of azimuthal audio-visual spatial coherence was performed. Furthermore, information on participant training and localization ability was gathered. The results are consistent with previous research and show that the proposed methodology is suitable for this kind of test. The main differences between participants result from the presence or absence of musical training.
Convention Paper 9758
P14-07 How Important Is Accurate Localization in Reproduced Sound?
Russell Mason (Presenting Author)
A meta-analysis was conducted on elicitation studies to examine the perceptual importance of localization-specific and localization-related attributes. It was found that the majority of attributes were localization-related, including (in order of commonality) extent, locatedness , distribution, spaciousness, and movement. The most common localization-specific attribute was distance, with only 2.6% of the attributes relating to the perceived lateral position. It is concluded that localization accuracy experiments may enable experimenters to make predictions about a reasonable proportion of the attributes found, though further research is needed to develop suitable analysis techniques. In addition, more research is required to develop subjective and objective methods for judging perceived distance.
Convention Paper 9759