EVALUATION OF AN AUTOMATIC SYSTEM FOR MEASURING HUMAN ECHOLOCATION ABILITY

Sammanfattning: To measure thresholds of human echolocation ability researchers need an automated system for the possibility to present a large set of stimuli. Previous studies have used recorded sounds or simulated sounds, allowing strict stimulus control at the expense of ecological validity. The purpose of this experiment was to test an automated system, that uses real objects. Fifteen participants tried the system and the task was to detect the presence of a disc, only using sound reflections. Detection thresholds as a function of distance to the reflecting object were determined using an adaptive staircase method. The mean threshold across participants was 1.7 m, which is in line with previous studies, using earphone presented sounds. Fairly large variability across individuals was observed. Two individuals performed very well with thresholds of > 2.5 m. Overall, the present experiment shows that the automated measuring system works well for assessing human echolocation ability.