Volume 5, 2021
|Number of page(s)||21|
|Section||Hearing, Audiology and Psychoacoustics|
|Published online||17 February 2021|
On the influence of non-individual binaural cues and the impact of level normalization on auditory distance estimation of nearby sound sources
Institute of Communications Engineering, TH Köln – University of Applied Sciences, Betzdorfer Str. 2, 50679 Cologne, Germany
2 Audio Communication Group, Technical University of Berlin, Einsteinufer 17c, 10587 Berlin, Germany
3 Department of Psychology, University of Bremen, Hochschulring 18, 28359 Bremen, Germany
4 Department of Psychology, Ludwig-Maximilians-Universität München, Leopoldstr. 13, 80802 Munich, Germany
* Corresponding author: Johannes.Arend@th-koeln.de
Accepted: 14 January 2021
Nearby sound sources provide distinct binaural cues, mainly in the form of interaural level differences, which vary with respect to distance and azimuth. However, there is a long-standing controversy regarding whether humans can actually utilize binaural cues for distance estimation of nearby sources. Therefore, we conducted three experiments using non-individual binaural synthesis. In Experiment 1, subjects had to estimate the relative distance of loudness-normalized and non-normalized nearby sources in static and dynamic binaural rendering in a multi-stimulus comparison task under anechoic conditions. Loudness normalization was used as a plausible method to compensate for noticeable intensity differences between stimuli. With the employed loudness normalization, nominal distance did not significantly affect distance ratings for most conditions despite the presence of non-individual binaural distance cues. In Experiment 2, subjects had to judge the relative distance between loudness-normalized sources in dynamic binaural rendering in a forced-choice task. Below chance performance in this more sensitive task revealed that the employed loudness normalization strongly affected distance estimation. As this finding indicated a general issue with loudness normalization for studies on relative distance estimation, Experiment 3 directly tested the validity of loudness normalization and a frequently used amplitude normalization. Results showed that both normalization methods lead to remaining (incorrect) intensity cues, which subjects most likely used for relative distance estimation. The experiments revealed that both examined normalization methods have consequential drawbacks. These drawbacks might in parts explain conflicting findings regarding the effectiveness of binaural cues for relative distance estimation in the literature.
© J.M. Arend et al., Published by EDP Sciences, 2020
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.