Unit for Visually Impaired People (U-VIP), Center for Human Technologies, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy.
Dipartimento di Informatica, Bioingegneria, Robotica e Ingegneria dei Sistemi (DIBRIS) Department, University of Genoa, Genoa, Italy.
Sci Rep. 2020 Apr 14;10(1):6279. doi: 10.1038/s41598-020-62983-z.
Although vision is important for calibrating auditory spatial perception, it only provides information about frontal sound sources. Previous studies of blind and sighted people support the idea that azimuthal spatial bisection in frontal space requires visual calibration, while detection of a change in azimuth (minimum audible angle, MAA) does not. The influence of vision on the ability to map frontal, lateral and back space has not been investigated. Performance in spatial bisection and MAA tasks was assessed for normally sighted blindfolded subjects using bursts of white noise presented frontally, laterally, or from the back relative to the subjects. Thresholds for both tasks were similar in frontal space, lower for the MAA task than for the bisection task in back space, and higher for the MAA task in lateral space. Two interpretations of the results are discussed, one in terms of visual calibration and the use of internal representations of source location and the other based on comparison of the magnitude or direction of change of the available binaural cues. That bisection thresholds were increased in back space relative to front space, where visual calibration information is unavailable, suggests that an internal representation of source location was used for the bisection task.
虽然视觉对于校准听觉空间感知很重要，但它只能提供关于正面声源的信息。先前对盲人和视力正常者的研究支持这样一种观点，即正面空间中的方位空间二分法需要视觉校准，而方位变化的检测（最小可听角，MAA）则不需要。视觉对正面、侧面和背面空间映射能力的影响尚未得到研究。使用相对于受试者正面、侧面或背面呈现的白噪声突发，评估了正常视力的蒙眼受试者在空间二分法和 MAA 任务中的表现。两个任务的阈值在正面空间中相似，在背面空间中 MAA 任务的阈值低于二分法任务，在侧面空间中 MAA 任务的阈值高于二分法任务。讨论了两种结果解释，一种是基于视觉校准和对声源位置的内部表示的使用，另一种是基于可用双耳线索的大小或方向变化的比较。二分法阈值在没有视觉校准信息的背面空间相对于正面空间增加，这表明内部声源位置表示被用于二分法任务。
