The Experts below are selected from a list of 10506 Experts worldwide ranked by ideXlab platform
Shigeaki Aoki - One of the best experts on this subject based on the ideXlab platform.
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Sound Localization of stereo reproduction with parametric loudspeakers
Applied Acoustics, 2012Co-Authors: Shigeaki Aoki, Masayoshi Toba, Norihisa TsujitaAbstract:Abstract A parametric loudspeaker radiates an audible signal by the interaction of the primary wave that is amplitude modulated and is known as a super-directivity loudspeaker. The parametric loudspeaker is one of the prominent applications of nonlinear acoustics. So far, the applications have been limited monaural reproduction Sound system for public address in museum, station, street etc. In this paper, we investigated Sound Localization of stereo reproduction using two parametric loudspeakers in comparison with that using two ordinary dynamic loudspeakers. In subjective tests, the binaural information ILD (Interaural Level Difference) or ITD (Interaural Time Delay) was focused on. To investigate the characteristics of Sound Localization in a wide listening area, three typical listening positions were picked up. Signals were 500 Hz, 1 kHz, 2 kHz and 4 kHz pure tones and pink noise. The used parametric loudspeaker was an equilateral hexagon. The subjective test led to the results that when the parametric loudspeakers were used, the listeners at the three typical listening positions perceived the correct Sound Localization of not only pure tone but also pink noise and when the ordinary dynamic loudspeakers were used, except for the case of pure tone with ITD, the tendency was almost similar to those using the parametric loudspeakers. The second subjective tests were conducted in order to investigate in details the difference between parametric loudspeakers and ordinary dynamic loudspeakers by increasing the number of subjects. In the case of ITD and 500 Hz using the ordinary dynamic loudspeakers, three types of Sound Localization were categorized, in which the reversed type was major and the normal and the other types were minor. The ILDs which were measured with a dummy head and were calculated with several formulas were almost the same and indicated the reasons of the reversed typed Sound Localization and a serious influence of the crosstalk. It was found that in the case of pure tone with ITD, the contradiction between the binaural information ILD and ITD is remarkable, because the directivity of the ordinary dynamic loudspeakers was so dull that the crosstalk components had a serious influence on Sound Localization. It was determined the parametric loudspeaker could transmit correct binaural information to the listener, because the directivity of the parametric loudspeakers was so sharp that it suppressed the cross talk components.
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Sound Localization During Head Movement Using an Acoustical Telepresence Robot : TeleHead
Advanced Robotics, 2009Co-Authors: Iwaki Toshima, Shigeaki AokiAbstract:Using our developed acoustical telepresence robot, TeleHead, we have so far confirmed that not only stationary binaural features, but also dynamic cues from head movement play important roles in Sound Localization. In this study, aiming towards the realization of an ideal acoustical telepresence robot, we clarify the relation between the head movement and the accuracy of Sound Localization in Sound Localization experiments. We examined two factors related to head movement that should have an impact on Sound Localization accuracy: observation from multiple postures and dynamic information during head movement. The results suggest that both factors improve the accuracy of Sound Localization in experiments. Moreover, even when we can use only one of these factors, the accuracy of Sound Localization is almost the same as the subject's original accuracy. The results confirm that even under very bad communication, control and head-shape conditions, the synchronization of head movement is important for building ...
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Sound Localization using an acoustical telepresence robot: Telehead ii
Presence: Teleoperators and Virtual Environments, 2008Co-Authors: Iwaki Toshima, Shigeaki Aoki, Tatsuya HiraharaAbstract:TeleHead I is an acoustical telepresence robot that we built on the basis of the concept that remote Sound Localization could be best achieved by using a user-like dummy head whose movement synchronizes with the user's head movement in real time. We clarified the characteristics of the latest version of TeleHead I, TeleHead II, and verified the validity of this concept by Sound Localization experiments. TeleHead II can synchronize stably with the user's head movement with a 120-ms delay. The driving noise level measured through headphones is below 24 dB SPL from 1 to 4 kHz. The shape difference between the dummy head and the user is about 3% in head width and 5% in head length. An overall measurement metric indicated that the difference between the head-related transfer functions (HRTFs) of the dummy head and the modeled listener is about 5 dB. The results of the Sound Localization experiments using TeleHead II clarified that head movement improves horizontal-plane Sound Localization performance even when the dummy head shape differs from the user's head shape. In contrast, the results for head movement when the dummy head shape and user head shape are different were inconsistent in the median plane. The accuracy of Sound Localization when using the same-shape dummy head with movement tethered to the user's head movement was always good. These results show that the TeleHead concept is acceptable for building an acoustical telepresence robot. They also show that the physical characteristics of TeleHead II are sufficient for conducting Sound Localization experiments.
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Audio teleconferencing systems with Sound Localization effects
The Journal of the Acoustical Society of America, 1999Co-Authors: Shigeaki Aoki, Manabu OkamotoAbstract:In teleconferencing, conversation should flow naturally between separate sites. The acoustic design should, of course, be able to at least convey the correct volume. However, Sound Localization is also very important for realizing the kind of virtual reality world that is teleconferencing. Coordinating the visual image (a speaker’s face) and the Sound image (his or her voice) creates a kind of virtual environment in which the participants at each site feel as if they are having a conversation in the same room. Two prototype teleconferencing systems with Sound Localization effects have been developed. The more primitive of the two is a small teleconferencing system that can connect two sites with stereo reproduction in a way that utilizes psychological acoustic phenomena. The other is a high‐presence system that aims at achieving a high level of ambience among three separate sites. Its features and key technologies are natural images on a large super‐high‐resolution display, good Sound Localization from remote locations through the use of a multichannel Sound image Localization system, and high‐definition images as a result of HDTV coding and transmission. The proposed multichannel Sound system comprises four subsystems, one each for Sound input, reproduction, acoustic feedback control, and transmission.
Rickye S. Heffner - One of the best experts on this subject based on the ideXlab platform.
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The Sound-Localization ability of cats.
Journal of Neurophysiology, 2005Co-Authors: Henry E. Heffner, Rickye S. HeffnerAbstract:The paper by Tollin and colleagues in the March 2005 issue of the Journal of Neurophysiology describes the Sound-Localization ability of cats trained to orient their eyes to the source of a Sound ([Tollin et al. 2005][1]). The main finding of this paper, which was the subject of an Editorial Focus
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passive Sound Localization ability of the big brown bat eptesicus fuscus
Hearing Research, 1998Co-Authors: Gimseong Koay, Henry E. Heffner, Dara Kearns, Rickye S. HeffnerAbstract:The passive Sound-Localization ability (i.e. minimum audible angle) of the big brown bat, Eptesicus fuscus, was determined using a conditioned avoidance procedure in which the animals were trained to discriminate left Sounds from right Sounds. The mean threshold of three bats for a 100-ms broadband noise burst was 14°, a value that is about average for mammals. A similar threshold of 15° was obtained for one animal when it was retested with one of its own recorded echolocation calls as the stimulus. The two bats tested on pure-tone Localization were able to localize high-frequency, but not low-frequency tones, even when a low-frequency tone was amplitude modulated, a result indicating that these bats are not able to use binaural time-difference cues for Localization. Finally, given the width of the bat's field of best vision, as determined by a count of its ganglion-cell density, its Sound-Localization acuity is consistent with the hypothesis that the role of passive Sound Localization is to direct the eyes to the source of a Sound.
Noboru Sugie - One of the best experts on this subject based on the ideXlab platform.
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A model-based Sound Localization system and its application to robot navigation
Robotics and Autonomous Systems, 1999Co-Authors: Jie Huang, Noboru Ohnishi, T. Supaongprapa, I. Terakura, Fuming Wang, Noboru SugieAbstract:This paper describes a mobile robot equipped with a real time Sound Localization system as well as a sonar system for obstacle detection. The Sound Localization method is based on a model of the precedence effect of the human auditory system to cope with echoes and reverberations. Sound Localization and robot navigation experiments were conducted. The results show that the robot is capable of localizing Sounding objects in a reverberant environment and approaching the objects without collisions, even when the objects were behind obstacles. Environment flexibility and error robustness of the system were discussed as well.
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Building ears for robots: Sound Localization and separation
Artificial Life and Robotics, 1997Co-Authors: Jie Huang, Noboru Ohnishi, Noboru SugieAbstract:This paper describes our research on bio-mimetic robot audition. Among the many binaural and monaural Sound Localization cues in the human auditory system, the interaural time difference cue is selected as it can easily be obtained by omnidirectional microphones. We have used a three-microphone system to remove the anterior-posterior ambiguity which occurs in two-microphone (or ear) systems. The echo-avoidance model of the precedence effect is used to cope with the echoes and reverberations of real environments. We mimicked the cocktail party effect by perceptual grouping of continuous components according to the spatial information obtained by the Sound Localization method. A wheel-based mobile robot equipped with an auditory system was developed. The auditory system has two Sound processing parts. One is a DSP-based realtime system; the other is an off-line system composed of remote computers. Experiments of localizing and separating multiple Sound sources and robot navigation were conducted to demonstrate the system's ability and potential applications.
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IROS - Mobile robot and Sound Localization
Proceedings of the 1997 IEEE RSJ International Conference on Intelligent Robot and Systems. Innovative Robotics for Real-World Applications. IROS '97, 1Co-Authors: Jie Huang, Noboru Ohnishi, T. Supaongprapa, I. Terakura, Noboru SugieAbstract:This paper describes a mobile robot equipped with a real time Sound Localization system as well as a sonar system for obstacle detection. The Sound Localization method is based on a model of the precedence effect of the human auditory system to cope with echoes and reverberations. The Sound Localization and robot navigation experiments were conducted. The results show that the robot is capable of localizing Sounding objects in a reverberant environment and approaching the objects without collisions, even when the objects were behind obstacles. Environment flexibility and error robustness of the system were discussed as well.
Yoiti Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Effects of listener's whole-body rotation and Sound duration on Sound Localization accuracy
Journal of the Acoustical Society of America, 2017Co-Authors: Akio Honda, Sayaka Tsunokake, Yoiti Suzuki, Shuichi SakamotoAbstract:Listener's head movement is known to facilitate Sound Localization, which creates dynamic changes to the information input to both ears. For this study, we used a digitally controlled spinning chair to examine the effects of a listener’s whole-body rotation and Sound duration on Sound Localization accuracy. We measured their Sound Localization accuracy at locations from left 30 deg to right 30 deg with respect to the listener. Stimuli were 1/3-octave band noise burst (fc = 1 kHz, SPL = 65 dB) with duration of 50, 200, and 1000 ms. Each stimulus was presented from a loudspeaker in a circular array. The listener, sitting on the chair at the circle center, reported the position of the presented stimulus in chair-still (0 deg/s) and chair-rotation (10 deg/s) conditions. Results showed superior Sound Localization accuracy of chair-rotation condition to that of a chair-still condition. Moreover, a significant effect of Sound duration was observed, but interaction of the test condition and the Sound duration was...
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Effects of a listener’s very slow rotation on Sound Localization accuracy
The Journal of the Acoustical Society of America, 2016Co-Authors: Sayaka Tsunokake, Yoiti Suzuki, Akio Honda, Shuichi SakamotoAbstract:A listener’s head movement is effectively used to accurately localize Sounds. By contrast, when a Sound stimulus is presented during head rotation, Sound Localization acuity decreases. Previous studies have shown that Sound Localization accuracy is degraded even during slow head rotation at 50/s. In this study, we investigated the Sound Localization accuracy during very slow head rotation from 0.6250/s to 50/s. We measured the detection thresholds (DTs) at the listener’s subjective front. The experiment consisted of static and rotation conditions. Listeners were asked to report whether a 30 ms noise burst was presented from the left or right of the subjective front (2 Alternative Forced Choice Task). In the results, the DTs in the rotation condition were larger than that in the static condition. Moreover, DTs seem almost independent of the rotation speed. This suggests that the Sound Localization resolution at the subjective front is degraded by a listener's passive rotation irrespective of the rotation s...
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Effects of Head Movement and Proprioceptive Feedback in Training of Sound Localization
i-Perception, 2013Co-Authors: Akio Honda, Hiroshi Shibata, Souta Hidaka, Jiro Gyoba, Yukio Iwaya, Yoiti SuzukiAbstract:We investigated the effects of listeners' head movements and proprioceptive feedback during Sound Localization practice on the subsequent accuracy of Sound Localization performance. The effects were examined under both restricted and unrestricted head movement conditions in the practice stage. In both cases, the participants were divided into two groups: a feedback group performed a Sound Localization drill with accurate proprioceptive feedback; a control group conducted it without the feedback. Results showed that (1) Sound Localization practice, while allowing for free head movement, led to improvement in Sound Localization performance and decreased actual angular errors along the horizontal plane, and that (2) proprioceptive feedback during practice decreased actual angular errors in the vertical plane. Our findings suggest that unrestricted head movement and proprioceptive feedback during Sound Localization training enhance perceptual motor learning by enabling listeners to use variable auditory cues and proprioceptive information.
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The Effects of Head Movement and Accurate Proprioceptive Feedback in Training of Sound Localization
i-Perception, 2011Co-Authors: Akio Honda, Hiroshi Shibata, Souta Hidaka, Jiro Gyoba, Yukio Iwaya, Yoiti SuzukiAbstract:We investigated the effects of listeners' head movement and proprioceptive feedback on the accuracy of Sound Localization. The effects were examined under the conditions that their head movement was restricted (study 1) or unrestricted (study 2) on the Sound Localization training. In both experiments, participants divided into two groups: training group performed the Sound Localization training with accurate proprioceptive feedback, while control group conducted the training with no-feedback. The results indicated that: (1) Sound Localization training under active head movements increased the accuracy of Sound Localization; (2) accurate proprioceptive feedback facilitated the Sound Localization during the initial training phase; and (3) training with the feedback dominantly decreased the rate of vertical Localization errors in Sound Localization performance.
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Detection Thresholds of Sound Image Movement Deteriorate during Sound Localization
i-Perception, 2011Co-Authors: Kagesho Ohba, Yukio Iwaya, Akio Honda, Yoiti SuzukiAbstract:Although a Sound position without head movement localized, front-back confusion frequently occurs. Moreover, Sound Localization accuracy, especially front-back confusion, can be dramatically improved by listener head movement. This clearly shows that in Sound Localization both static cues involved in the Sound signal input to the two ears and dynamic cues caused by listener motion are used. However, there have been few studies concerning spatial hearing dynamic situations. In this study, therefore, listener detection thresholds of movement of a Sound stimulus during a Sound Localization task with head rotation were measured. Participants were first trained to rotate their heads at an indicated speed. Then during a Sound Localization trial, they were instructed to rotate their heads the direction of a Sound stimulus at the speed. As a 2AFC paradigm was used, in one of two successive trials, the Sound position (azimuthal angle) slightly moved during the rotation. Participants were asked to judge in which trial the Sound stimuli moved. Results revealed that detection thresholds were dynamically raised when participants rotated their heads. Moreover, this effect did not depend on the velocities. These findings may suggest that a process similar to saccadic suppression in vision exists in dynamic Sound Localization
Gary D Paige - One of the best experts on this subject based on the ideXlab platform.
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Influence of aging on human Sound Localization
Journal of Neurophysiology, 2011Co-Authors: Marina S. Dobreva, William O'neill, Gary D PaigeAbstract: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.
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Plasticity in human Sound Localization induced by compressed spatial vision
Nature Neuroscience, 2003Co-Authors: Marcel P. Zwiers, A. John Van Opstal, Gary D PaigeAbstract:Auditory and visual target locations are encoded differently in the brain, but must be co-calibrated to maintain cross-sensory concordance. Mechanisms that adjust spatial calibration across modalities have been described (for example, prism adaptation in owls), though rudimentarily in humans. We quantified the adaptation of human Sound Localization in response to spatially compressed vision (0.5x lenses for 2-3 days). This induced a corresponding compression of auditory Localization that was most pronounced for azimuth (minimal for elevation) and was restricted to the visual field of the lenses. Sound Localization was also affected outside the field of visual-auditory interaction (shifted centrally, not compressed). These results suggest that spatially modified vision induces adaptive changes in adult human Sound Localization, including novel mechanisms that account for spatial compression. Findings are consistent with a model in which the central processing of Sound location is encoded by recruitment rather than by a place code.