auditory localization
Recently Published Documents


TOTAL DOCUMENTS

288
(FIVE YEARS 20)

H-INDEX

35
(FIVE YEARS 1)

Author(s):  
Lore Thaler ◽  
Liam J. Norman

AbstractWhat factors are important in the calibration of mental representations of auditory space? A substantial body of research investigating the audiospatial abilities of people who are blind has shown that visual experience might be an important factor for accurate performance in some audiospatial tasks. Yet, it has also been shown that long-term experience using click-based echolocation might play a similar role, with blind expert echolocators demonstrating auditory localization abilities that are superior to those of people who are blind and who do not use click-based echolocation by Vercillo et al. (Neuropsychologia 67: 35–40, 2015). Based on this hypothesis we might predict that training in click-based echolocation may lead to improvement in performance in auditory localization tasks in people who are blind. Here we investigated this hypothesis in a sample of 12 adult people who have been blind from birth. We did not find evidence for an improvement in performance in auditory localization after 10 weeks of training despite significant improvement in echolocation ability. It is possible that longer-term experience with click-based echolocation is required for effects to develop, or that other factors can explain the association between echolocation expertise and superior auditory localization. Considering the practical relevance of click-based echolocation for people who are visually impaired, future research should address these questions.


2021 ◽  
Vol 17 (5) ◽  
pp. e1008973
Author(s):  
Lakshitha P. Wijesinghe ◽  
Melville J. Wohlgemuth ◽  
Richard H. Y. So ◽  
Jochen Triesch ◽  
Cynthia F. Moss ◽  
...  

Animals utilize a variety of active sensing mechanisms to perceive the world around them. Echolocating bats are an excellent model for the study of active auditory localization. The big brown bat (Eptesicus fuscus), for instance, employs active head roll movements during sonar prey tracking. The function of head rolls in sound source localization is not well understood. Here, we propose an echolocation model with multi-axis head rotation to investigate the effect of active head roll movements on sound localization performance. The model autonomously learns to align the bat’s head direction towards the target. We show that a model with active head roll movements better localizes targets than a model without head rolls. Furthermore, we demonstrate that active head rolls also reduce the time required for localization in elevation. Finally, our model offers key insights to sound localization cues used by echolocating bats employing active head movements during echolocation.


2020 ◽  
pp. 244-252
Author(s):  
Edmund T. Rolls

Mechanisms for left-right auditory localization involving time differences for low frequencies, and intensity differences for high frequencies, performed in the brainstem are described. Auditory localization in 3D space using the pinna as an asymmetrical antenna is described. The auditory cortical areas in the superior temporal gyrus are hierarchically organised and can detect feature combinations. Auditory neurons in the orbitofrontal cortex and nearby inferior frontal gyrus can respond to vocalizations used in communication; and the human orbitofrontal cortex is involved in identifying the emotional expression in a voice, which is useful in social behaviour.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Manon Carrière ◽  
Helena Cassol ◽  
Charlène Aubinet ◽  
Rajanikant Panda ◽  
Aurore Thibaut ◽  
...  

Abstract Auditory localization (i.e. turning the head and/or the eyes towards an auditory stimulus) is often part of the clinical evaluation of patients recovering from coma. The objective of this study is to determine whether auditory localization could be considered as a new sign of minimally conscious state, using a multimodal approach. The presence of auditory localization and the clinical outcome at 2 years of follow-up were evaluated in 186 patients with severe brain injury, including 64 with unresponsive wakefulness syndrome, 28 in minimally conscious state minus, 71 in minimally conscious state plus and 23 who emerged from the minimally conscious state. Brain metabolism, functional connectivity and graph theory measures were investigated by means of 18F-fluorodeoxyglucose positron emission tomography, functional MRI and high-density electroencephalography in two subgroups of unresponsive patients, with and without auditory localization. These two subgroups were also compared to a subgroup of patients in minimally conscious state minus. Auditory localization was observed in 13% of unresponsive patients, 46% of patients in minimally conscious state minus, 62% of patients in minimally conscious state plus and 78% of patients who emerged from the minimally conscious state. The probability to observe an auditory localization increased along with the level of consciousness, and the presence of auditory localization could predict the level of consciousness. Patients with auditory localization had higher survival rates (at 2-year follow-up) than those without localization. Differences in brain function were found between unresponsive patients with and without auditory localization. Higher connectivity in unresponsive patients with auditory localization was measured between the fronto-parietal network and secondary visual areas, and in the alpha band electroencephalography network. Moreover, patients in minimally conscious state minus significantly differed from unresponsive patients without auditory localization in terms of brain metabolism and alpha network centrality, whereas no difference was found with unresponsive patients who presented auditory localization. Our multimodal findings suggest differences in brain function between unresponsive patients with and without auditory localization, which support our hypothesis that auditory localization should be considered as a new sign of minimally conscious state. Unresponsive patients showing auditory localization should therefore no longer be considered unresponsive but minimally conscious. This would have crucial consequences on these patients’ lives as it would directly impact the therapeutic orientation or end-of-life decisions usually taken based on the diagnosis.


CoDAS ◽  
2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Maria Fernanda Capoani Garcia Mondelli ◽  
Marina De Marchi dos Santos ◽  
Mariza Ribeiro Feniman

ABSTRACT Purpose To assess the hearing abilities of temporal ordering, temporal resolution and sound localization before and after the fitting of a hearing aid (HA) in individuals with unilateral hearing loss (UHL). Methods There were evaluated 22 subjects, aged 18 to 60 years, diagnosed with sensorineural or mixed UHL, from mild to severe degrees. The study was divided into two stages: the pre and post-adaptation of HA. In both phases, subjects performed an interview, application of Questionnaire for Disabilities Associated with Impaired Auditory Localization, auditory processing screening protocol (APSP) and Random Gap Detection Test (RGDT). Results This study found no statistically significant difference in sound localization and memory evaluations for verbal sounds in sequence, in RGDT and Questionnaire for Disabilities Associated with Impaired Auditory Localization. Conclusion With the effective use of hearing aids, individuals with UHL showed improvement in the auditory abilities of sound localization, ordering and temporal resolution.


2019 ◽  
Author(s):  
David Aagten-Murphy ◽  
Martin Szinte ◽  
Robert Taylor ◽  
Heiner Deubel

AbstractVisual objects that are present both before and after eye movements can act as landmarks, aiding localization of other visual stimuli. We investigated whether visual landmarks would also influence auditory localization – despite participants’ head position remaining unchanged. Participants made eye-movements from central fixation to a peripheral visual landmark, which either remained stationary or was covertly displaced. Following the movement, participants judged whether a stimulus (auditory or visual) was shifted in location relative to before the movement. Visual localization estimates shifted along with the landmark, although the landmark displacement itself went unnoticed. Interestingly, auditory localization estimates were also displaced. Thus, despite identical auditory input reaching the ears, two auditory stimuli originating from the same position were perceived as spatially distinct when the visual landmark moved. These results are consistent with the idea that auditory spatial information is encoded within an eye-centered reference frame and subject to spatial recalibration by visual landmarks.HighlightsVisual landmarks affect stimulus localization across eye movementsWe show this also for auditory stimuli, even when the head remains stableDue to a visual landmark displacement, identical auditory stimuli are perceived as shiftedThis suggests that auditory space is calibrated on eye-centered maps across saccades


Sign in / Sign up

Export Citation Format

Share Document