Table 1.
Naivety rated on 1-5 scale of experience: 1 (> 9 hours), 2 (> 6 hours), 3 (> 3 hours), 4 (> 0 hours), 5 (= 0 hours). Virtual-reality/gaming frequency rated 1-5: 1 (no experience), 2 (rarely), 3 (several times a year), 4 (monthly), 5 (regularly).
Fig 1.
Virtual reality visualisation and implementation of simulated echolocation and distance-dependent hum volume modulation (humming).
(A) Example of a randomly-generated maze with a single path to goal of 7 cube steps. Orange glow indicates humming boundary in the humming sonification. Golden star indicates goal. Red cross + black dot indicate starting position. (B) Example of a corridor with randomly positioned obstacles. Orange glows and red dotted lines indicate humming boundaries in the humming sonification. Golden star indicates goal. Red cross + black dot indicate starting position. (C) Virtual reality visualisation of the maze. (D) Implementation of simulated echolocation. A pool of 900 particles is projected along a 30 × 30 grid array of rays from the (x, y, z) position of the Tango. (E) Virtual reality visualisation of the obstacle corridor.
Fig 2.
Hardware set-up with the Project Tango and the Durovis Dive 7 head mount.
(A) Participant wearing the Tango mounted in the Durovis Dive 7 headset with a pair of stereo headphones. (B) Rear-facing camera hardware of Project Tango tablet. (C & D) 90° field of view vertically and horizontally from the position of the Tango.
Fig 3.
Spectral frequency displays of the additive sinusoidal hums used in the distance-dependent hum volume modulation sonification method.
Each column (horizontal axis) corresponds to a hum, with its frequency components/notes shown on the vertical axis. The blue band indicates the hum’s core frequency, while the red and orange bands indicate other prominent frequencies.
Fig 4.
Maze navigational behaviours and results.
(A, B, & C) Examples of participant trajectories through a maze, using visual-only cues (A), echolocation audio-only cues (B), and humming audio-only cues (C). (D, E, F, & H) Basic efficiency and strategy of navigation through the maze in the visual (purple), echolocation (blue) and humming (green) conditions: time to reach goal in seconds (D), path length in metres (E), mean velocity in metres per second (F), and summed left and right midline deviation in metres (H). Error bars indicate standard error. Statistical significance indicated as follows: not significant (n.s.), p < .05(*), p < .01(**) and p < .001(***). (G) Summed left and right head rotation in degrees. Head rotation from head straight (0°) direction, comparing visual (purple), echolocation (blue) and humming (green) conditions in the maze. Error bars indicate standard error. Statistical significance indicated as follows: not significant (n.s.), p < .05(*), p < .01(**) and p < .001(***). (I, J, & K) Learning curves over 6 trials comparing visual (purple), echolocation (blue) and humming (green) conditions in the maze: time to complete in seconds (I), summed left and right midline deviation in metres (J) and summed left and right head rotation in degrees (K). Linear regression line with R2-statistic shown for each condition in corresponding colours. Error bars indicate standard error. Significance symbols mark significance of effect between first and sixth trial. Statistical significance indicated as follows: not significant (not shown), p < .05(*), p < .01(**) and p < .001(***).
Fig 5.
Obstacle corridor navigational behaviours and results.
(A, B, & C) Examples of participant trajectories through particular obstacle corridor arrangements using visual-only cues (A), echolocation audio-only cues (B), and humming audio-only cues (C). (D, J, & K) Active interaction with obstacles in the corridor in the visual (purple), echolocation (blue) and humming (green) conditions: number of obstacles encountered at least once per trial (D), obstacle deviation distance (J), and percentage of obstacle patch time per trial spent <0.4m from left or right wall (K). Red dashed line shows 3m echolocation and humming threshold. Error bars indicate standard error. Statistical significance indicated as follows: not significant (n.s.), p < .05(*), p < .01(**) and p < .001(***). (E, F, G, & H) Basic efficiency of navigation through the obstacle corridor in the visual (purple), echolocation (blue) and humming (green) conditions: total number of collisions over 6 trials per participant (E), time to reach goal in seconds (F), path length in metres (G), mean velocity in metres per second (H). Error bars indicate standard error. Statistical significance indicated as follows: not significant (n.s.), p < .05(*), p < .01(**) and p < .001(***). (I) Summed left and right head rotation from head straight (0°) direction in the corridor in the visual (purple), echolocation (blue) and humming (green) conditions. Error bars indicate standard error. Statistical significance indicated as follows: not significant (n.s.), p < .05(*), p < .01(**) and p < .001(***). (L, M, & N) Learning curves over 6 trials comparing visual (purple), echolocation (blue) and humming (green) conditions in the obstacle corridor: time to complete in seconds (L), summed left and right head rotation in degrees (M), obstacle deviation distance in metres (N). Red dashed line shows 3m echolocation and humming threshold. Linear regression line with R2-statistic shown for each condition in corresponding colours. Error bars indicate standard error. Significance symbols mark significance of effect between first and sixth trial. Statistical significance indicated as follows: not significant (not shown), p < .05(*), p < .01(**) and p < .001(***).
Fig 6.
Qualitative participant feedback.
(A)“How easy/intuitive did you find the echolocation sonification in each environment?” (B)“How easy/intuitive did you find the humming sonification in each environment?” Green: easy. Yellow: manageable with training. Orange: challenging even with training. Red: impossible.