Localization of a virtual wall by means of active echolocation by untrained sighted persons

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

“…Fig 17 shows some degree of correlation in the case of a far wall and reflection only, suggesting that when the echo spectra are not masked by the direct sound, their difference can to some extent be detected.…”

“…Fig17 shows some degree of correlation in the case of a far wall and reflection only, suggesting that when the echo spectra are not masked by the direct sound, their difference can to some extent be detected.Fig18shows some degree of correlation in the case of a nearby wall with a normal or RDLD enhanced echo. Apparently, people's perception of the non-smoothness of the reflection spectrum is enhanced when the echo can be referenced with the direct sound.Overall, the found correlations are relatively weak, and it can be expected that a test person is able to take multiple spectro-temporal features into account when trying to decide whether two echoes are different or not.…”

“…The latter sounds are the two most used among the echolocator community. Oral clicks, also called tongue or palatal clicks, look like a Bessel pulse [14] and are the most commonly used stimuli by echolocators providing a high performance to perform echolocation task [14][15][16], due to their impulsive nature (Full Width Half Maximum envelope duration of about 3ms) and high sound pressure level (sound exposure level 35-65dB) [17]. Hisses, due to their wide spectrum (>5kHz) and long duration (order of 1 second or more) are particularly efficient for short range detection, by exploiting the spectral coloration of the perceived sound, which is caused by frequency dependent interference between reflected and direct sound [18,19] varying proportionally to the source bandwidth [20].…”

A Participatory Design Approach to Creating Echolocation-Enabled Virtual Environments

“…These attempts have had diferent goals. For example, Wu et al [103] used pre-recorded sounds and echoes in a grid-like maze to teach people how to use echolocation; Andreasen et al [6] argued that the use of echolocation may improve ownership over the virtual space, Neidhardt et al [65] and Pelegrin et al [70] used their implementation of echolocation to ind out whether participants could identify a virtual wall and orient themselves towards it. Dodsworth et al [28] and Andrade et al [5] argued that echolocation may assist people with visual impairment in acquiring spatial information and forming a mental map of virtual space.…”

“…Previous research has included and even been co-authored by expert echolocators (for example, [96]). Some of this research has attempted to replicate echolocationÐthe use of sound and echoes produced by sound relecting of diferent surfaces [50,51]Ðto improve accessibility in digital games and VR experiences for people with visual impairment [2,6,28,58,70,84,103]. Echolocation has been used, for example, to help detect obstacles [77,84], and to support the formation of mental maps of virtual space [5,28,40,58].…”