Department of Psychology, Durham University, Science Site, South Road, Durham, DH1 3LE, UK.
Eindhoven University of Technology, Eindhoven, The Netherlands.
J Assoc Res Otolaryngol. 2019 Oct;20(5):499-510. doi: 10.1007/s10162-019-00728-0. Epub 2019 Jul 8.
Some people who are blind have trained themselves in echolocation using mouth clicks. Here, we provide the first report of psychophysical and clicking data during echolocation of distance from a group of 8 blind people with experience in mouth click-based echolocation (daily use for > 3 years). We found that experienced echolocators can detect changes in distance of 3 cm at a reference distance of 50 cm, and a change of 7 cm at a reference distance of 150 cm, regardless of object size (i.e. 28.5 cm vs. 80 cm diameter disk). Participants made mouth clicks that were more intense and they made more clicks for weaker reflectors (i.e. same object at farther distance, or smaller object at same distance), but number and intensity of clicks were adjusted independently from one another. The acuity we found is better than previous estimates based on samples of sighted participants without experience in echolocation or individual experienced participants (i.e. single blind echolocators tested) and highlights adaptation of the perceptual system in blind human echolocators. Further, the dynamic adaptive clicking behaviour we observed suggests that number and intensity of emissions serve separate functions to increase SNR. The data may serve as an inspiration for low-cost (i.e. non-array based) artificial 'cognitive' sonar and radar systems, i.e. signal design, adaptive pulse repetition rate and intensity. It will also be useful for instruction and guidance for new users of echolocation.
一些失明的人通过口腔点击来训练自己的回声定位能力。在这里，我们提供了第一组 8 名有经验的基于口腔点击回声定位的盲人的心理物理和点击数据的报告，这些人每天使用该技术的时间超过 3 年。我们发现，有经验的回声定位者可以检测到 50 厘米参考距离处 3 厘米的距离变化，以及 150 厘米参考距离处 7 厘米的距离变化，而与物体大小无关（即 28.5 厘米与 80 厘米直径的圆盘）。参与者发出的口腔点击更强烈，并且对于较弱的反射器（即距离较远的相同物体或相同距离处较小的物体）发出更多的点击，但点击的数量和强度是相互独立调整的。我们发现的敏锐度优于以前基于没有回声定位经验的有视力参与者的样本或单个有经验的参与者（即单个盲回声定位者测试）的估计，这突显了盲人回声定位者的感知系统的适应性。此外，我们观察到的动态自适应点击行为表明，发射的数量和强度具有不同的功能，可以提高信噪比。这些数据可以为低成本（即非基于阵列的）人工“认知”声纳和雷达系统提供灵感，例如信号设计、自适应脉冲重复率和强度。它对于新的回声定位用户的指导和指导也将非常有用。
