scholarly journals Re-weighting of Sound Localization Cues by Audiovisual Training

2019 ◽  
Author(s):  
Daniel P. Kumpik ◽  
Connor Campbell ◽  
Jan W.H. Schnupp ◽  
Andrew J King

AbstractSound localization requires the integration in the brain of auditory spatial cues generated by interactions with the external ears, head and body. Perceptual learning studies have shown that the relative weighting of these cues can change in a context-dependent fashion if their relative reliability is altered. One factor that may influence this process is vision, which tends to dominate localization judgments when both modalities are present and induces a recalibration of auditory space if they become misaligned. It is not known, however, whether vision can alter the weighting of individual auditory localization cues. Using non-individualized head-related transfer functions, we measured changes in subjects’ sound localization biases and binaural localization cue weights after ~55 minutes of training on an audiovisual spatial oddball task. Four different configurations of spatial congruence between visual and auditory cues (interaural time differences (ITDs) and frequency-dependent interaural level differences (interaural level spectra, ILS) were used. When visual cues were spatially congruent with both auditory spatial cues, we observed an improvement in sound localization, as shown by a reduction in the variance of subjects’ localization biases, which was accompanied by an up-weighting of the more salient ILS cue. However, if the position of either one of the auditory cues was randomized during training, no overall improvement in sound localization occurred. Nevertheless, the spatial gain of whichever cue was matched with vision increased, with different effects observed on the gain for the randomized cue depending on whether ITDs or ILS were matched with vision. As a result, we observed a similar up-weighting in ILS when this cue alone was matched with vision, but no overall change in binaural cue weighting when ITDs corresponded to the visual cues and ILS were randomized. Consistently misaligning both cues with vision produced the ventriloquism aftereffect, i.e., a corresponding shift in auditory localization bias, without affecting the variability of the subjects’ sound localization judgments, and no overall change in binaural cue weighting. These data show that visual contextual information can invoke a reweighting of auditory localization cues, although concomitant improvements in sound localization are only likely to accompany training with fully congruent audiovisual information.


2000 ◽  
Vol 83 (4) ◽  
pp. 2300-2314 ◽  
Author(s):  
U. Koch ◽  
B. Grothe

To date, most physiological studies that investigated binaural auditory processing have addressed the topic rather exclusively in the context of sound localization. However, there is strong psychophysical evidence that binaural processing serves more than only sound localization. This raises the question of how binaural processing of spatial cues interacts with cues important for feature detection. The temporal structure of a sound is one such feature important for sound recognition. As a first approach, we investigated the influence of binaural cues on temporal processing in the mammalian auditory system. Here, we present evidence that binaural cues, namely interaural intensity differences (IIDs), have profound effects on filter properties for stimulus periodicity of auditory midbrain neurons in the echolocating big brown bat, Eptesicus fuscus. Our data indicate that these effects are partially due to changes in strength and timing of binaural inhibitory inputs. We measured filter characteristics for the periodicity (modulation frequency) of sinusoidally frequency modulated sounds (SFM) under different binaural conditions. As criteria, we used 50% filter cutoff frequencies of modulation transfer functions based on discharge rate as well as synchronicity of discharge to the sound envelope. The binaural conditions were contralateral stimulation only, equal stimulation at both ears (IID = 0 dB), and more intense at the ipsilateral ear (IID = −20, −30 dB). In 32% of neurons, the range of modulation frequencies the neurons responded to changed considerably comparing monaural and binaural (IID =0) stimulation. Moreover, in ∼50% of neurons the range of modulation frequencies was narrower when the ipsilateral ear was favored (IID = −20) compared with equal stimulation at both ears (IID = 0). In ∼10% of the neurons synchronization differed when comparing different binaural cues. Blockade of the GABAergic or glycinergic inputs to the cells recorded from revealed that inhibitory inputs were at least partially responsible for the observed changes in SFM filtering. In 25% of the neurons, drug application abolished those changes. Experiments using electronically introduced interaural time differences showed that the strength of ipsilaterally evoked inhibition increased with increasing modulation frequencies in one third of the cells tested. Thus glycinergic and GABAergic inhibition is at least one source responsible for the observed interdependence of temporal structure of a sound and spatial cues.



2013 ◽  
Vol 24 (09) ◽  
pp. 782-788 ◽  
Author(s):  
Xuan Zhong ◽  
William A. Yost

Background: Maintaining balance is known to be a multisensory process that uses information from different sensory organs. Although it has been known for a long time that spatial hearing cues provide humans with moderately accurate abilities to localize sound sources, how the auditory system interacts with balance mediated by the vestibular system remains largely a mystery. Purpose: The primary goal of the current study was to determine whether auditory spatial cues obtained from a fixed sound source can help human participants balance themselves as compared to conditions in which participants use vision. Research Design: The experiment uses modified versions of conventional clinical tests: the Tandem Romberg test and the Fukuda Stepping test. In the Tandem Romberg test, participants stand with their feet in a heel-to-toe position, and try to maintain balance for 40 sec. In the Fukuda Stepping test, a participant is asked to close his or her eyes and to march in place for 100 steps. The sway and angular deviation of each participant was measured with and without vision and spatial auditory cues. An auditory spatial reference was provided by presenting a broadband noise source from a loudspeaker directly in front of the participant located 1–2 m away. Study Sample: A total of 19 participants (11 women and 8 men; mean age = 27 yr; age range = 18 ˜ 52 yr), voluntarily participated in the experiment. All participants had normal vision, hearing, and vestibular function. Intervention: The primary intervention was the use of a broadband noise source to provide an auditory spatial referent for balance measurements in the Tandem Romberg test and Fukuda Stepping test. Conditions were also tested in which the participants had their eyes opened or closed. Data Collection and Analysis: A head tracker recorded the position of the participant's head for the Tandem Romberg test. The angular deviation of the feet after 100 steps was measured in the Fukuda Stepping test. An average distance or angle moved by the head or feet was calculated relative to the head or feet resting position for each test. The average head sway or angular deviation was measured in an eyes-open condition (no sound), eyes-closed condition (no sound), and an eyes-closed condition with sound. Repeated-measures analysis of variance was used for both tests. Results: The results showed a significant benefit in postural stability in both experiments when spatial auditory cues were present (p < .01). For the Tandem Romberg test, the benefit from spatial auditory cues alone is a 9% reduction in mean sway, as compared to 44% from visual cues alone. For the Fukuda Stepping test, the benefit from spatial auditory cues alone is a 76% reduction in mean body sway, as compared to 98% from visual cues alone. Conclusions: The current study demonstrated a connection between spatial hearing and balance. The experiments showed that a single fixed sound source can provide sufficient spatial cues for the central nervous system to better control postural stability. The compensation effect that the vestibular system receives from the auditory cues, however, is weaker than that received from visual cues.



2019 ◽  
Author(s):  
Yuqi Deng ◽  
Inyong Choi ◽  
Barbara Shinn-Cunningham ◽  
Robert Baumgartner

AbstractSpatial selective attention enables listeners to process a signal of interest in natural settings. However, most past studies on auditory spatial attention used impoverished spatial cues: presenting competing sounds to different ears, using only interaural differences in time (ITDs) and/or intensity (IIDs), or using non-individualized head-related transfer functions (HRTFs). Here we tested the hypothesis that impoverished spatial cues impair spatial auditory attention by only weakly engaging relevant cortical networks. Eighteen normal-hearing listeners reported the content of one of two competing syllable streams simulated at roughly +30 ° and −30° azimuth. The competing streams consisted of syllables from two different-sex talkers. Spatialization was based on natural spatial cues (individualized HRTFs), individualized IIDs, or generic ITDs. We measured behavioral performance as well as electroencephalographic markers of selective attention. Behaviorally, subjects recalled target streams most accurately with natural cues. Neurally, spatial attention significantly modulated early evoked sensory response magnitudes only for natural cues, not in conditions using only ITDs or IIDs. Consistent with this, parietal oscillatory power in the alpha band (8-14 Hz; associated with filtering out distracting events from unattended directions) showed significantly less attentional modulation with isolated spatial cues than with natural cues. Our findings support the hypothesis that spatial selective attention networks are only partially engaged by impoverished spatial auditory cues. These results not only suggest that studies using unnatural spatial cues underestimate the neural effects of spatial auditory attention, they also illustrate the importance of preserving natural spatial cues in assistive listening devices to support robust attentional control.



1974 ◽  
Vol 26 (2) ◽  
pp. 235-251 ◽  
Author(s):  
James R. Lackner

Studies of auditory localization revealed that where a subject hears a sound is dependent on both his perceived head position and the auditory cues at his ears. If an error is induced between his true and registered head posture, then errors in his auditory localizations of corresponding size and time course result. The presence of visual information prevents the development of postural errors and, consequently, prevents the development of errors in auditory localization, too. These observations are related to the oculogravic illusion and are interpreted as one aspect of the functioning of a spatial reference system involved in the maintenance of the constancies of auditory and visual detection.



2019 ◽  
Vol 6 (7) ◽  
pp. 190423 ◽  
Author(s):  
L. Papet ◽  
N. Grimault ◽  
N. Boyer ◽  
N. Mathevon

As top predators, crocodilians have an acute sense of hearing that is useful for their social life and for probing their environment in hunting situations. Although previous studies suggest that crocodilians are able to localize the position of a sound source, how they do this remains largely unknown. In this study, we measured the potential monaural sound localization cues (head-related transfer functions; HRTFs) on alive animals and skulls in two situations, both mimicking natural positions: basking on the land and cruising at the interface between air and water. Binaural cues were also estimated by measuring the interaural level differences (ILDs) and the interaural time differences (ITDs). In both conditions, HRTF measurements show large spectral variations (greater than 10 dB) for high frequencies, depending on the azimuthal angle. These localization cues are influenced by head size and by the internal coupling of the ears. ITDs give reliable information regarding sound-source position for low frequencies, while ILDs are more suitable for frequencies higher than 1.5 kHz. Our results support the hypothesis that crocodilian head morphology is adapted to acquire reliable localization cues from sound sources when outside the water, but also when only a small part of their head is above the air–water interface.



2007 ◽  
Author(s):  
Marco Sperduti ◽  
Ralf Veit ◽  
Andrea Caria ◽  
Paolo Belardinelli ◽  
Niels Birbaumer ◽  
...  


Author(s):  
Adam F. Werner ◽  
Jamie C. Gorman

Objective This study examines visual, auditory, and the combination of both (bimodal) coupling modes in the performance of a two-person perceptual-motor task, in which one person provides the perceptual inputs and the other the motor inputs. Background Parking a plane or landing a helicopter on a mountain top requires one person to provide motor inputs while another person provides perceptual inputs. Perceptual inputs are communicated either visually, auditorily, or through both cues. Methods One participant drove a remote-controlled car around an obstacle and through a target, while another participant provided auditory, visual, or bimodal cues for steering and acceleration. Difficulty was manipulated using target size. Performance (trial time, path variability), cue rate, and spatial ability were measured. Results Visual coupling outperformed auditory coupling. Bimodal performance was best in the most difficult task condition but also high in the easiest condition. Cue rate predicted performance in all coupling modes. Drivers with lower spatial ability required a faster auditory cue rate, whereas drivers with higher ability performed best with a lower rate. Conclusion Visual cues result in better performance when only one coupling mode is available. As predicted by multiple resource theory, when both cues are available, performance depends more on auditory cueing. In particular, drivers must be able to transform auditory cues into spatial actions. Application Spotters should be trained to provide an appropriate cue rate to match the spatial ability of the driver or pilot. Auditory cues can enhance visual communication when the interpersonal task is visual with spatial outputs.



1976 ◽  
Vol 28 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Philip Merikle

Report of single letters from centrally-fixated, seven-letter, target rows was probed by either auditory or visual cues. The target rows were presented for 100 ms, and the report cues were single digits which indicated the spatial location of a letter. In three separate experiments, report was always better with the auditory cues. The advantage for the auditory cues was maintained both when target rows were masked by a patterned stimulus and when the auditory cues were presented 500 ms later than comparable visual cues. The results indicate that visual cues produce modality-specific interference which operates at a level of processing beyond iconic representation.



i-Perception ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 204166952110271
Author(s):  
Aijun Wang ◽  
Heng Zhou ◽  
Yuanyuan Hu ◽  
Qiong Wu ◽  
Tianyang Zhang ◽  
...  

The Colavita effect refers to the phenomenon wherein people tend to not respond to an auditory stimulus when a visual stimulus is simultaneously presented. Although previous studies have shown that endogenous modality attention influences the Colavita effect, whether the Colavita effect is influenced by endogenous spatial attention remains unknown. In the present study, we established endogenous spatial cues to investigate whether the size of the Colavita effect changes under visual or auditory cues. We measured three indexes to investigate the effect of endogenous spatial attention on the size of the Colavita effect. These three indexes were developed based on the following observations in bimodal trials: (a) The proportion of the “only vision” response was significantly higher than that of the “only audition” response; (b) the proportion of the “vision precedes audition” response was significantly higher than that of the “audition precedes vision” response; and (c) the reaction time difference of the “vision precedes audition” response was significantly higher than that of the “audition precedes vision” response. Our results showed that the Colavita effect was always influenced by endogenous spatial attention and that its size was larger at the cued location than at the uncued location; the cue modality (visual vs. auditory) had no effect on the size of the Colavita effect. Taken together, the present results shed light on how endogenous spatial attention affects the Colavita effect.



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