scholarly journals Sound source localization with varying amount of visual information in virtual reality

2018 ◽  
Author(s):  
Axel Ahrens ◽  
Kasper Duemose Lund ◽  
Marton Marschall ◽  
Torsten Dau
Keyword(s):  
Virtual Reality ◽  
Visual Perception ◽  
Sound Localization ◽  
Visual Information ◽  
Right Hemisphere ◽  
Transfer Functions ◽  
Head Movements ◽  
Localization Accuracy ◽  
Localization Performance ◽  
The Right

AbstractTo achieve accurate spatial auditory perception, subjects typically require personal head-related transfer functions (HRTFs) and the freedom for head movements. Loudspeaker-based virtual sound environments allow for realism without individualized measurements. To study audio-visual perception in realistic environments, the combination of spatially tracked head mounted displays (HMDs), also known as virtual reality glasses, and virtual sound environments may be valuable. However, HMDs were recently shown to affect the subjects’ HRTFs and thus might influence sound localization performance. Furthermore, due to limitations of the reproduction of visual information on the HMD, audio-visual perception might be influenced. Here, a sound localization experiment was conducted both with and without an HMD and with a varying amount of visual information provided to the subjects. Furthermore, interaural time and level difference errors (ITDs and ILDs) as well as spectral perturbations induced by the HMD were analyzed and compared to the perceptual localization data. The results showed a reduction of the localization accuracy when the subjects were wearing an HMD and when they were blindfolded. The HMD-induced error in azimuth localization was found to be larger in the left than in the right hemisphere. Thus, the errors in ITD and ILD can only partly account for the perceptual differences. When visual information of the limited set of source locations was provided, the localization error induced by the HMD was found to be negligible. Presenting visual information of hand-location, room dimensions, source locations and pointing feedback on the HMD revealed similar effects as previously shown in real environments.

scholarly journals Ambisonics Sound Source Localization With Varying Amount of Visual Information in Virtual Reality

2021 ◽  
Vol 2 ◽  
Author(s):  
Thirsa Huisman ◽  
Axel Ahrens ◽  
Ewen MacDonald
Keyword(s):  
Virtual Reality ◽  
Visual Information ◽  
Right Hemisphere ◽  
Sound Field ◽  
Auditory Stimuli ◽  
Spatial Cues ◽  
Sound Sources ◽  
Acoustic Localization ◽  
Localization Performance ◽  
The Right

To reproduce realistic audio-visual scenarios in the laboratory, Ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, Ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st-, 3rd-, 5th- or 11th-order Ambisonics with and without visual information. Results showed that with 1st-order Ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small. The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the Ambisonics order, there was no interaction between the Ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using Ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of the auditory stimuli.

scholarly journals Experiments on localization accuracy with non-individual and individual HRTFs comparing static and dynamic reproduction methods

2020 ◽  
Author(s):  
Josefa Oberem ◽  
Jan-Gerrit Richter ◽  
Dorothea Setzer ◽  
Julia Seibold ◽  
Iring Koch ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Transfer Functions ◽  
Real Life ◽  
Good Reproducibility ◽  
Sound Sources ◽  
Clear Trend ◽  
Listening Test ◽  
Localization Accuracy ◽  
Life Conditions ◽  
The Right

AbstractBinaural reproduction can be used in listening experiments under real-life conditions to achieve a high realism and good reproducibility. In recent years a clear trend to more individual reproduction can be observed as the ability to measure individual head-related-transfer-functions (HRTFs) is becoming more widespread. The question of the accuracy and reproduction methods needed for a realistic playback however has not been sufficiently answered. To evaluate an appropriate approach for binaural reproduction via headphones different head-related-transfer-functions (HRTFs) and reproduction methods were compared in this paper. In a listening test eleven explicitly trained participants were asked to localize eleven sound sources positioned in the right hemisphere using the proximal pointing method. Binaural stimuli based on individually measured HRTFs were compared to those of an artificial head in a static reproduction of stimuli and in three dynamic reproduction methods of different resolutions (5°, 2.5° and 1°). Unsigned errors in azimuth and elevation as well as front-back-confusions and in-head-localization were observed. Dynamic reproduction of any resolution applied turned out fundamental for a reduction of undesired front-back-confusions and in-head-localization. Individually measured HRTFs showed a smaller effect on localization accuracy compared to the influence of dynamic sound reproduction. They were mainly observed to reduce the front-back-confusion rate.

scholarly journals Sound source localization in virtual reality with ambisonics sound reproduction

2021 ◽  
Author(s):  
Thirsa Huisman ◽  
Axel Ahrens ◽  
Ewen MacDonald
Keyword(s):  
Virtual Reality ◽  
Visual Information ◽  
Right Hemisphere ◽  
Sound Field ◽  
Auditory Stimuli ◽  
Spatial Cues ◽  
Sound Sources ◽  
Acoustic Localization ◽  
Sound Reproduction ◽  
The Right

To reproduce realistic audio-visual scenarios in the laboratory, ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st, 3rd, 5th or 11th order ambisonics with and without visual information. Results showed that with 1st order ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small.The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the ambisonics order, there was no interaction between the ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of auditory stimuli.

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

Sound-Localization Performance in the Cat: The Effect of Restraining the Head

2005 ◽  
Vol 93 (3) ◽  
pp. 1223-1234 ◽  
Author(s):  
Daniel J. Tollin ◽  
Luis C. Populin ◽  
Jordan M. Moore ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Short Duration ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Localization Accuracy ◽  
Head Restraint ◽  
The Gaze ◽  
Long Duration ◽  
Localization Performance ◽  
Visual Targets

In oculomotor research, there are two common methods by which the apparent location of visual and/or auditory targets are measured, saccadic eye movements with the head restrained and gaze shifts (combined saccades and head movements) with the head unrestrained. Because cats have a small oculomotor range (approximately ±25°), head movements are necessary when orienting to targets at the extremes of or outside this range. Here we tested the hypothesis that the accuracy of localizing auditory and visual targets using more ethologically natural head-unrestrained gaze shifts would be superior to head-restrained eye saccades. The effect of stimulus duration on localization accuracy was also investigated. Three cats were trained using operant conditioning with their heads initially restrained to indicate the location of auditory and visual targets via eye position. Long-duration visual targets were localized accurately with little error, but the locations of short-duration visual and both long- and short-duration auditory targets were markedly underestimated. With the head unrestrained, localization accuracy improved substantially for all stimuli and all durations. While the improvement for long-duration stimuli with the head unrestrained might be expected given that dynamic sensory cues were available during the gaze shifts and the lack of a memory component, surprisingly, the improvement was greatest for the auditory and visual stimuli with the shortest durations, where the stimuli were extinguished prior to the onset of the eye or head movement. The underestimation of auditory targets with the head restrained is explained in terms of the unnatural sensorimotor conditions that likely result during head restraint.

Split brains

2018 ◽  
Author(s):  
Elizabeth Schechter
Keyword(s):  
Visual Field ◽  
Information Exchange ◽  
Visual Information ◽  
Right Hemisphere ◽  
The Other ◽  
Brain Surgery ◽  
Interhemispheric Interaction ◽  
Split Brain ◽  
The One ◽  
The Right

The largest fibre tract in the human brain connects the two cerebral hemispheres. A ‘split-brain’ surgery severs this structure, sometimes together with other white matter tracts connecting the right hemisphere and the left. Split-brain surgeries have long been performed on non-human animals for experimental purposes, but a number of these surgeries were also performed on adult human beings in the second half of the twentieth century, as a medical treatment for severe cases of epilepsy. A number of these people afterwards agreed to participate in ongoing research into the psychobehavioural consequences of the procedure. These experiments have helped to show that the corpus callosum is a significant source of interhemispheric interaction and information exchange in the ‘neurotypical’ brain. After split-brain surgery, the two hemispheres operate unusually independently of each other in the realm of perception, cognition, and the control of action. For instance, each hemisphere receives visual information directly from the opposite (‘contralateral’) side of space, the right hemisphere from the left visual field and the left hemisphere from the right visual field. This is true of the normal (‘neurotypical’) brain too, but in the neurotypical case interhemispheric tracts allow either hemisphere to gain access to the information that the other has received. In a split-brain subject however the information more or less stays put in whatever hemisphere initially received it. And it isn’t just visual information that is confined to one hemisphere or the other after the surgery. Rather, after split-brain surgery, each hemisphere is the source of proprietary perceptual information of various kinds, and is also the source of proprietary memories, intentions, and aptitudes. Various notions of psychological unity or integration have always been central to notions of mind, personhood, and the self. Although split-brain surgery does not prevent interhemispheric interaction or exchange, it naturally alters and impedes it. So does the split-brain subject as a whole nonetheless remain a unitary psychological being? Or could there now be two such psychological beings within one human animal – sharing one body, one face, one voice? Prominent neuropsychologists working with the subjects have often appeared to argue or assume that a split-brain subject has a divided or disunified consciousness and even two minds. Although a number of philosophers agree, the majority seem to have resisted these conscious and mental ‘duality claims’, defending alternative interpretations of the split-brain experimental results. The sources of resistance are diverse, including everything from a commitment to the necessary unity of consciousness, to recognition of those psychological processes that remain interhemispherically integrated, to concerns about what the moral and legal consequences would be of recognizing multiple psychological beings in one body. On the other hand underlying most of these arguments against the various ‘duality’ claims is the simple fact that the split-brain subject does not appear to be two persons, but one – and there are powerful conceptual, social, and moral connections between being a unitary person on the one hand and having a unified consciousness and mind on the other.

scholarly journals Fundamental Nature of Human Infant's Brain Asymmetry

1977 ◽  
Vol 4 (3) ◽  
pp. 203-207 ◽  
Author(s):  
Juhn A. Wada ◽  
Alan E. Davis
Keyword(s):  
Visual Information ◽  
Right Hemisphere ◽  
Functional Implication ◽  
Speech Stimuli ◽  
Morphological Asymmetry ◽  
Developmental Factors ◽  
Verbal Content ◽  
The Right ◽  
Temporal Coherency

SUMMARY:Morphological speech zone asymmetry in man cannot be due to environmental or developmental factors after birth. The functional implication of such a finding is not yet clear. Morphological asymmetry of the human brain is paralleled by electrophysiological evidence of cerebral hemispheric asymmetries. The results of our analysis of 50 infants suggest that clear occipital-temporal coherency asymmetry similar, but not identical to the adult pattern, also exists at or near birth. These asymmetries are generated by stimuli with no verbal content and in infants who presumably have no or an undeveloped capability for language. It is suggested that language is only a part of much more fundamental asymmetries which include the processing of auditory and visual information. Our results, and those of others, are consistent with the assumption that the left hemisphere is more able to relate stimuli to past experience, either short or long-term, while the right hemisphere is more able to process stimuli which are not easily identifiable or referable. These capabilities would not be based on language, and hence would be expected to develop independently and possibly before speech. The demonstration that reversing electrophysiological asymmetries can be generated with non-speech stimuli in the visual and auditory modalities, and in neonates, supports such an assumption.

scholarly journals Virtual reality-based sensorimotor adaptation shapes subsequent spontaneous and naturalistic stimulus-driven brain activity

2021 ◽  
Author(s):  
Meytal Wilf ◽  
Celine Dupuis ◽  
Davide Nardo ◽  
Diana Huber ◽  
Sibilla Sander ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Large Scale ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Visual Response ◽  
Spatial Shift ◽  
Before And After ◽  
Behavioural Tests ◽  
The Right

Our everyday life summons numerous novel sensorimotor experiences, to which our brain needs to adapt in order to function properly. However, tracking plasticity of naturalistic behaviour and associated brain modulations is challenging. Here we tackled this question implementing a prism adaptation training in virtual reality (VRPA) in combination with functional neuroimaging. Three groups of healthy participants (N=45) underwent VRPA (with a spatial shift either to the left/right side, or with no shift), and performed fMRI sessions before and after training. To capture modulations in free-flowing, task-free brain activity, the fMRI sessions included resting state and free viewing of naturalistic videos. We found significant decreases in spontaneous functional connectivity between large-scale cortical networks, namely attentional and default mode/fronto-parietal networks, only for adaptation groups. Additionally, VRPA was found to bias visual representations of naturalistic videos, as following rightward adaptation, we found upregulation of visual response in an area in the parieto-occipital sulcus (POS) in the right hemisphere. Notably, the extent of POS upregulation correlated with the size of the VRPA induced after-effect measured in behavioural tests. This study demonstrates that a brief VRPA exposure is able to change large-scale cortical connectivity and correspondingly bias the representation of naturalistic sensory inputs.

scholarly journals Independent means of business communication in manager personnel

2018 ◽  
Vol 20 (86) ◽  
pp. 48-52
Author(s):  
K.M. Hirniak
Keyword(s):  
Personnel Management ◽  
Visual Information ◽  
Right Hemisphere ◽  
Human Resources Management ◽  
Business Communication ◽  
Management Tools ◽  
Business Partners ◽  
Tone Of Voice ◽  
Verbal Messages ◽  
The Right

Non-verbal means of business communication for the personnel management system are considered in the article. Business communication is disclosed as the communication of various meetings with personal acquaintance, which is a necessary component of cooperation with non-verbal means. Individual substantiation of non-verbal communication, built on the system of non-verbal characters, serving as means for the exchange of information between people. Research is used to provide information transmitted by verbal means (only words) by about 7%, only by voice – by 38% (in particular due to the tone of voice, intonation and other sounds) and non-verbal means – 55%. Non-verbal messages have certain features, they are: unstructured, can not be decomposed into separate components; tied to the terms of communication; non-intentional, spontaneous; more innate than acquired; are formed under the dominant influence of the right hemisphere of the brain. It is proved that there are reasons to trust non-verbal means of communication. The emphasis is on the management of personnel, which obliges to business communication and determined by the ability to correctly interpret the visual information, as well as the partner's look, his facial expressions, gestures, timbre and tempo of the language. Ability to recognize non-verbal signals allows a business person: the ability to recognize the obstacles that arise at the level of personal relationships at the time of their origin, intercept and neutralize the corresponding signals, rebuild a conversation with these signals, change the timing of the conversation; the ability to verify the correctness of their interpretation of signals. The purpose of this article is to study non-verbal (non-verbal) human resources management tools used in business communication. In the course of the presentation of the article came to the conclusion that non-verbal means of business communication can provide some assistance in achieving the desired result in the process of negotiations with business partners or in personnel management; feelings, emotions, relationships of people, allows you to convey proper information, the content of which is reviewed by language, that is verbal means. In the future, we see that non-verbal means of business communication in the management of personnel, which must comply with the norms and verbal etiquette adopted in the appropriate environment, as well as intellectual and professional levels.

scholarly journals Overlapping Anatomical Networks Convey Cross-Modal Suppression in the Sighted and Coactivation of “Visual” and Auditory Cortex in the Blind

2019 ◽  
Vol 29 (11) ◽  
pp. 4863-4876 ◽  
Author(s):  
Irina Anurova ◽  
Synnöve Carlson ◽  
Josef P Rauschecker
Keyword(s):  
Sound Localization ◽  
Right Hemisphere ◽  
Adaptive Plasticity ◽  
Identification Task ◽  
Fmri Study ◽  
Inferior Longitudinal Fasciculus ◽  
Visual Areas ◽  
Frontal White Matter ◽  
The Right ◽  
Anterior Thalamic Radiation

Abstract In the present combined DTI/fMRI study we investigated adaptive plasticity of neural networks involved in controlling spatial and nonspatial auditory working memory in the early blind (EB). In both EB and sighted controls (SC), fractional anisotropy (FA) within the right inferior longitudinal fasciculus correlated positively with accuracy in a one-back sound localization but not sound identification task. The neural tracts passing through the cluster of significant correlation connected auditory and “visual” areas in the right hemisphere. Activity in these areas during both sound localization and identification correlated with FA within the anterior corpus callosum, anterior thalamic radiation, and inferior fronto-occipital fasciculus. In EB, FA in these structures correlated positively with activity in both auditory and “visual” areas, whereas FA in SC correlated positively with activity in auditory and negatively with activity in visual areas. The results indicate that frontal white matter conveys cross-modal suppression of occipital areas in SC, while it mediates coactivation of auditory and reorganized “visual” cortex in EB.

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