scholarly journals Effects of amplitude modulation on sound localization in reverberant environments.

2015 ◽  
Author(s):  
Paul Anderson
Neuron ◽  
2009 ◽  
Vol 62 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Sasha Devore ◽  
Antje Ihlefeld ◽  
Kenneth Hancock ◽  
Barbara Shinn-Cunningham ◽  
Bertrand Delgutte

2021 ◽  
Vol 2 (2) ◽  
pp. 146-163
Author(s):  
Sebastian Schneider ◽  
Paul Wilhelm Dierkes

Locating a vocalizing animal can be useful in many fields of bioacoustics and behavioral research, and is often done in the wild, covering large areas. In zoos, however, the application of this method becomes particularly difficult, because, on the one hand, the animals are in a relatively small area and, on the other hand, reverberant environments and background noise complicate the analysis. Nevertheless, by localizing and analyzing animal sounds, valuable information on physiological state, sex, subspecies, reproductive state, social status, and animal welfare can be gathered. Therefore, we developed a sound localization software that is able to estimate the position of a vocalizing animal precisely, making it possible to assign the vocalization to the corresponding individual, even under difficult conditions. In this study, the accuracy and reliability of the software is tested under various conditions. Different vocalizations were played back through a loudspeaker and recorded with several microphones to verify the accuracy. In addition, tests were carried out under real conditions using the example of the giant otter enclosure at Dortmund Zoo, Germany. The results show that the software can estimate the correct position of a sound source with a high accuracy (median of the deviation 0.234 m). Consequently, this software could make an important contribution to basic research via position determination and the associated differentiation of individuals, and could be relevant in a long-term application for monitoring animal welfare in zoos.


2015 ◽  
Vol 114 (5) ◽  
pp. 2991-3001 ◽  
Author(s):  
Andrew D. Brown ◽  
Heath G. Jones ◽  
Alan Kan ◽  
Tanvi Thakkar ◽  
G. Christopher Stecker ◽  
...  

Normal-hearing human listeners and a variety of studied animal species localize sound sources accurately in reverberant environments by responding to the directional cues carried by the first-arriving sound rather than spurious cues carried by later-arriving reflections, which are not perceived discretely. This phenomenon is known as the precedence effect (PE) in sound localization. Despite decades of study, the biological basis of the PE remains unclear. Though the PE was once widely attributed to central processes such as synaptic inhibition in the auditory midbrain, a more recent hypothesis holds that the PE may arise essentially as a by-product of normal cochlear function. Here we evaluated the PE in a unique human patient population with demonstrated sensitivity to binaural information but without functional cochleae. Users of bilateral cochlear implants (CIs) were tested in a psychophysical task that assessed the number and location(s) of auditory images perceived for simulated source-echo (lead-lag) stimuli. A parallel experiment was conducted in a group of normal-hearing (NH) listeners. Key findings were as follows: 1) Subjects in both groups exhibited lead-lag fusion. 2) Fusion was marginally weaker in CI users than in NH listeners but could be augmented by systematically attenuating the amplitude of the lag stimulus to coarsely simulate adaptation observed in acoustically stimulated auditory nerve fibers. 3) Dominance of the lead in localization varied substantially among both NH and CI subjects but was evident in both groups. Taken together, data suggest that aspects of the PE can be elicited in CI users, who lack functional cochleae, thus suggesting that neural mechanisms are sufficient to produce the PE.


2007 ◽  
Vol 27 (7) ◽  
pp. 1782-1790 ◽  
Author(s):  
M. Pecka ◽  
T. P. Zahn ◽  
B. Saunier-Rebori ◽  
I. Siveke ◽  
F. Felmy ◽  
...  

2019 ◽  
Author(s):  
Jean-Hugues Lestang ◽  
Dan F. M. Goodman

Sound localization in reverberant environments is a difficult task that human listeners perform effortlessly. Many neural mechanisms have been proposed to account for this behavior. Generally they rely on emphasizing localization information at the onset of the incoming sound while discarding localization cues that arrive later. We modelled several of these mechanisms using neural circuits commonly found in the brain and tested their performance in the context of experiments showing that, in the dominant frequency region for sound localisation, we have a preference for auditory cues arriving during the rising slope of the sound energy (Dietz et al., 2013). We found that both single cell mechanisms (onset and adaptation) and population mechanisms (lateral inhibition) were easily able to reproduce the results across a very wide range of parameter settings. This suggests that sound localization in reverberant environments may not require specialised mechanisms specific to perform that task, but could instead rely on common neural circuits in the brain. This would allow for the possibility of individual differences in learnt strategies or neuronal parameters. This research is fully reproducible, and we made our code available to edit and run online via interactive live notebooks.


Sign in / Sign up

Export Citation Format

Share Document