Human echolocation: 2D shape discrimination using features extracted from acoustic echoes

Abstract

Some blind humans have developed the ability to perceive their silent surrounding by using echolocation based on tongue clicks. Past research has also shown that blind echolocators can use information gained from multiple echoic ‘views’, provided through head movements, to successfully identify 2D shapes. Here, echo features that might be used by blind humans to discriminate 2D shapes are investigated. Echoes from four shapes are collected with a custom-built acoustic radar and various features are extracted. By piecing together individual features across the measurement plane, it is found that total power and spectral centroid are two salient features for shape discrimination from multiple echoic views.