Discrimination of 2D wall textures by passive echolocation for different reflected-to-direct level difference configurations

Echovis – A collection of human echolocation tests performed by blind and sighted individuals: A pilot study

The article presents research on the echolocation skills of blind and sighted individuals gathered for the purpose of development of an echolocation training app. The goal of the research was to determine the influence of the environment type, reverberation, clicking patterns, and the average differences between the two tested groups. Ten blind and 10 sighted subjects were tested in various echolocation tasks – stationary, moving, indoor and outdoor, using mechanical clickers, and artificially generated clicks. Ten blind children also took part in the static indoor tests. The tests were repeated using binaural recordings and spatially rendered virtual audio. The following parameters and dependencies between them were analyzed: correctness of the obstacle localization, certainty of answer, type of environment and clicker sound, and frequency and number of clicks. It was found that the number of clicks influenced the correctness and certainty of the answer in case of obstacle direction determination, but not the distance. Better results were obtained in outdoor environments and in an empty room, what implies that reverberation has a positive influence on echolocation. The expected success rates in tested echolocation tasks provided a comparison of the echolocation abilities of blind and sighted subjects and set a benchmark for future tests.

Tom Pouce III, an Electronic White Cane for Blind People: Ability to Detect Obstacles and Mobility Performances

We present a protocol for evaluating the efficiency of an electronic white cane for improving the mobility of blind people. The electronic cane used during the test is the Tom Pouce III, made of LIDAR sensors (light detection and ranging) with tactile feedback. The protocol comprises two parts. The first part, the "detection test", evaluates the efficiency of the sensors in the Tom Pouce III for detecting the obstacles found in everyday life (thin and large poles, apertures) under different environmental conditions (darkness, sun light, rain). The second part of the test, the "mobility test", compares the ability of blind participants to cross a 25 m path by avoiding obstacles with the simple white cane and the electronic cane. The 12 blind participants had between 2 and 20 years of experience of everyday usage of Tom Pouce devices. The results show a significant improvement in the capacity to avoid obstacles with the electronic cane relative to the simple white cane, and there was no speed difference. There was no correlation between the results and the years of experience of the users.