The source and effects of binaural cue ambiguity in free-field stereo sound localization—Modeling simulation

2017 ◽  
Vol 141 (5) ◽  
pp. 3637-3638
Author(s):  
Yi Zhou ◽  
Christopher Montagne
Keyword(s):  
Sound Localization ◽  
Free Field ◽  
Modeling Simulation

scholarly journals Sound Localization Test in Presence of Noise (Sound Localization Test) in Adults without Hearing Alteration

2019 ◽  
Vol 23 (03) ◽  
pp. e276-e280
Author(s):  
Gleide Viviani Maciel Almeida ◽  
Angela Ribas ◽  
Jorge Calleros
Keyword(s):  
Sound Localization ◽  
Free Field ◽  
Normal Hearing ◽  
Average Score ◽  
Test Environment ◽  
Noise Interference ◽  
Localization Test ◽  
The Subject ◽  
Set Up ◽  
The Right

Introduction Even people with normal hearing may have difficulties locating a sound source in unfavorable sound environments where competitive noise is intense. Objective To develop, describe, validate and establish the normality curve of the sound localization test. Method The sample consisted of 100 healthy subjects with normal hearing, > 18 years old, who agreed to participate in the study. The sound localization test was applied after the subjects underwent a tonal audiometry exam. For this purpose, a calibrated free field test environment was set up. Then, 30 random pure tones were presented in 2 speakers placed at 45° (on the right and on the left sides of the subject), and the noise was presented from a 3rd speaker, placed at 180°. The noise was presented in 3 hearing situations: optimal listening condition (no noise), noise in relation to 0 dB, and noise in relation to - 10 dB. The subject was asked to point out the side where the pure tone was being perceived, even in the presence of noise. Results All of the 100 participants performed the test in an average time of 99 seconds. The average score was 21, the medium score was 23, and the standard deviation was 3.05. Conclusion The sound localization test proved to be easy to set-up and to apply. The results obtained in the validation of the test suggest that individuals with normal hearing should locate 70% of the presented stimuli. The test can constitute an important instrument in the measurement of noise interference in the ability to locate the sound.

A comparison of free-field and headphone based sound localization tasks

2018 ◽  
Vol 143 (3) ◽  
pp. 1814-1814 ◽  
Author(s):  
Devon Brichetto ◽  
Brock Carlson ◽  
Mary Landis Gaston ◽  
Thomas Olson ◽  
Jeremy Loebach
Keyword(s):  
Sound Localization ◽  
Free Field

scholarly journals Bimodal Cochlear Implant Listeners’ Ability to Perceive Minimal Audible Angle Differences

2019 ◽  
Vol 30 (08) ◽  
pp. 659-671 ◽  
Author(s):  
Ashley Zaleski-King ◽  
Matthew J. Goupell ◽  
Dragana Barac-Cikoja ◽  
Matthew Bakke
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
Repeated Measures ◽  
Free Field ◽  
Low Frequency ◽  
Spatial Location ◽  
Speech Understanding ◽  
Repeated Measures Design ◽  
Acoustic Environments ◽  
The Right

AbstractBilateral inputs should ideally improve sound localization and speech understanding in noise. However, for many bimodal listeners [i.e., individuals using a cochlear implant (CI) with a contralateral hearing aid (HA)], such bilateral benefits are at best, inconsistent. The degree to which clinically available HA and CI devices can function together to preserve interaural time and level differences (ITDs and ILDs, respectively) enough to support the localization of sound sources is a question with important ramifications for speech understanding in complex acoustic environments.To determine if bimodal listeners are sensitive to changes in spatial location in a minimum audible angle (MAA) task.Repeated-measures design.Seven adult bimodal CI users (28–62 years). All listeners reported regular use of digital HA technology in the nonimplanted ear.Seven bimodal listeners were asked to balance the loudness of prerecorded single syllable utterances. The loudness-balanced stimuli were then presented via direct audio inputs of the two devices with an ITD applied. The task of the listener was to determine the perceived difference in processing delay (the interdevice delay [IDD]) between the CI and HA devices. Finally, virtual free-field MAA performance was measured for different spatial locations both with and without inclusion of the IDD correction, which was added with the intent to perceptually synchronize the devices.During the loudness-balancing task, all listeners required increased acoustic input to the HA relative to the CI most comfortable level to achieve equal interaural loudness. During the ITD task, three listeners could perceive changes in intracranial position by distinguishing sounds coming from the left or from the right hemifield; when the CI was delayed by 0.73, 0.67, or 1.7 msec, the signal lateralized from one side to the other. When MAA localization performance was assessed, only three of the seven listeners consistently achieved above-chance performance, even when an IDD correction was included. It is not clear whether the listeners who were able to consistently complete the MAA task did so via binaural comparison or by extracting monaural loudness cues. Four listeners could not perform the MAA task, even though they could have used a monaural loudness cue strategy.These data suggest that sound localization is extremely difficult for most bimodal listeners. This difficulty does not seem to be caused by large loudness imbalances and IDDs. Sound localization is best when performed via a binaural comparison, where frequency-matched inputs convey ITD and ILD information. Although low-frequency acoustic amplification with a HA when combined with a CI may produce an overlapping region of frequency-matched inputs and thus provide an opportunity for binaural comparisons for some bimodal listeners, our study showed that this may not be beneficial or useful for spatial location discrimination tasks. The inability of our listeners to use monaural-level cues to perform the MAA task highlights the difficulty of using a HA and CI together to glean information on the direction of a sound source.

Sound Localization in Free Field and Interaural Threshold Differences

1964 ◽  
Vol 57 (sup188) ◽  
pp. 293-297
Author(s):  
Thorleif Sohoel ◽  
Gunnar Arnesen ◽  
Kjell Gjavenes
Keyword(s):  
Sound Localization ◽  
Free Field

scholarly journals Influence of aging on human sound localization

2011 ◽  
Vol 105 (5) ◽  
pp. 2471-2486 ◽  
Author(s):  
Marina S. Dobreva ◽  
William E. O'Neill ◽  
Gary D. Paige
Keyword(s):  
Sound Localization ◽  
Target Location ◽  
Free Field ◽  
Auditory Target ◽  
Intensity Difference ◽  
Middle Aged ◽  
Auditory Temporal Processing ◽  
Age Related ◽  
Low Pass ◽  
High Pass

Errors in sound localization, associated with age-related changes in peripheral and central auditory function, can pose threats to self and others in a commonly encountered environment such as a busy traffic intersection. This study aimed to quantify the accuracy and precision (repeatability) of free-field human sound localization as a function of advancing age. Head-fixed young, middle-aged, and elderly listeners localized band-passed targets using visually guided manual laser pointing in a darkened room. Targets were presented in the frontal field by a robotically controlled loudspeaker assembly hidden behind a screen. Broadband targets (0.1–20 kHz) activated all auditory spatial channels, whereas low-pass and high-pass targets selectively isolated interaural time and intensity difference cues (ITDs and IIDs) for azimuth and high-frequency spectral cues for elevation. In addition, to assess the upper frequency limit of ITD utilization across age groups more thoroughly, narrowband targets were presented at 250-Hz intervals from 250 Hz up to ∼2 kHz. Young subjects generally showed horizontal overestimation (overshoot) and vertical underestimation (undershoot) of auditory target location, and this effect varied with frequency band. Accuracy and/or precision worsened in older individuals for broadband, high-pass, and low-pass targets, reflective of peripheral but also central auditory aging. In addition, compared with young adults, middle-aged, and elderly listeners showed pronounced horizontal localization deficiencies (imprecision) for narrowband targets within 1,250–1,575 Hz, congruent with age-related central decline in auditory temporal processing. Findings underscore the distinct neural processing of the auditory spatial cues in sound localization and their selective deterioration with advancing age.

Aurally Aided Visual Search under Virtual and Free-Field Listening Conditions

1996 ◽  
Vol 38 (4) ◽  
pp. 702-715 ◽  
Author(s):  
David R. Perrott ◽  
John Cisneros ◽  
Richard L. Mckinley ◽  
William R. D'Angelo
Keyword(s):  
Visual Search ◽  
Sound Localization ◽  
Visual Target ◽  
Free Field ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Visually Guided ◽  
Guided Search ◽  
Minimum Latency ◽  
Initial Line

We examined the minimum latency required to locate and identify a visual target (visual search) in a two-alternative forced-choice paradigm in which the visual target could appear from any azimuth (0° to 360°) and from a broad range of elevations (from 90° above to 70° below the horizon) relative to a person's initial line of gaze. Seven people were tested in six conditions: unaided search, three aurally aided search conditions, and two visually aided search conditions. Aurally aided search with both actual and virtual sound localization cues proved to be superior to unaided and visually guided search. Application of synthesized three dimensional and two-dimensional sound cues in the workstations are discussed.

scholarly journals Unraveling the Relation between EEG Correlates of Attentional Orienting and Sound Localization Performance: A Diffusion Model Approach

2020 ◽  
Vol 32 (5) ◽  
pp. 945-962
Author(s):  
Laura-Isabelle Klatt ◽  
Daniel Schneider ◽  
Anna-Lena Schubert ◽  
Christina Hanenberg ◽  
Jörg Lewald ◽  
...  
Keyword(s):  
Diffusion Model ◽  
Sound Localization ◽  
Drift Rate ◽  
Free Field ◽  
Decision Time ◽  
Model Parameters ◽  
Alpha Power ◽  
Model Framework ◽  
Performance Accuracy ◽  
Localization Performance

Understanding the contribution of cognitive processes and their underlying neurophysiological signals to behavioral phenomena has been a key objective in recent neuroscience research. Using a diffusion model framework, we investigated to what extent well-established correlates of spatial attention in the electroencephalogram contribute to behavioral performance in an auditory free-field sound localization task. Younger and older participants were instructed to indicate the horizontal position of a predefined target among three simultaneously presented distractors. The central question of interest was whether posterior alpha lateralization and amplitudes of the anterior contralateral N2 subcomponent (N2ac) predict sound localization performance (accuracy, mean RT) and/or diffusion model parameters (drift rate, boundary separation, non-decision time). Two age groups were compared to explore whether, in older adults (who struggle with multispeaker environments), the brain–behavior relationship would differ from younger adults. Regression analyses revealed that N2ac amplitudes predicted drift rate and accuracy, whereas alpha lateralization was not related to behavioral or diffusion modeling parameters. This was true irrespective of age. The results indicate that a more efficient attentional filtering and selection of information within an auditory scene, reflected by increased N2ac amplitudes, was associated with a higher speed of information uptake (drift rate) and better localization performance (accuracy), while the underlying response criteria (threshold separation), mean RTs, and non-decisional processes remained unaffected. The lack of a behavioral correlate of poststimulus alpha power lateralization constrasts with the well-established notion that prestimulus alpha power reflects a functionally relevant attentional mechanism. This highlights the importance of distinguishing anticipatory from poststimulus alpha power modulations.

scholarly journals Ear-Specific Hemispheric Asymmetry in Unilateral Deafness Revealed by Auditory Cortical Activity

2021 ◽  
Vol 15 ◽  
Author(s):  
Ji-Hye Han ◽  
Jihyun Lee ◽  
Hyo-Jeong Lee
Keyword(s):  
Sound Localization ◽  
Hemispheric Asymmetry ◽  
Free Field ◽  
Binaural Hearing ◽  
Cortical Reorganization ◽  
Speech Sounds ◽  
Delayed Reaction ◽  
Unilateral Deafness ◽  
The Difference ◽  
The Right

Profound unilateral deafness reduces the ability to localize sounds achieved via binaural hearing. Furthermore, unilateral deafness promotes a substantial change in cortical processing to binaural stimulation, thereby leading to reorganization over the whole brain. Although distinct patterns in the hemispheric laterality depending on the side and duration of deafness have been suggested, the neurological mechanisms underlying the difference in relation to behavioral performance when detecting spatially varied cues remain unknown. To elucidate the mechanism, we compared N1/P2 auditory cortical activities and the pattern of hemispheric asymmetry of normal hearing, unilaterally deaf (UD), and simulated acute unilateral hearing loss groups while passively listening to speech sounds delivered from different locations under open free field condition. The behavioral performances of the participants concerning sound localization were measured by detecting sound sources in the azimuth plane. The results reveal a delayed reaction time in the right-sided UD (RUD) group for the sound localization task and prolonged P2 latency compared to the left-sided UD (LUD) group. Moreover, the RUD group showed adaptive cortical reorganization evidenced by increased responses in the hemisphere ipsilateral to the intact ear for individuals with better sound localization whereas left-sided unilateral deafness caused contralateral dominance in activity from the hearing ear. The brain dynamics of right-sided unilateral deafness indicate greater capability of adaptive change to compensate for impairment in spatial hearing. In addition, cortical N1 responses to spatially varied speech sounds in unilateral deaf people were inversely related to the duration of deafness in the area encompassing the right auditory cortex, indicating that early intervention would be needed to protect from maladaptation of the central auditory system following unilateral deafness.

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