Table 1.
Participants taking part in echolocation trials.
Fig 1.
The echolocation experiment setup.
The large obstacle was placed in one of 9 possible positions and the participants made a guess about its position, i.e. its direction (left, center, right) and distance (1 m, 2 m, 3 m). The answer was given first after a single echolocation signal (mouth click, hand clap or played back from a waist-height speaker worn on a lanyard) and then after N (up to 10) additional signal repetitions. Each participant went through all 9 locations in a random order in 10 separate sessions using different sounds.
Fig 2.
Comparison of sounds used for echolocation.
Table 2.
Mixed ANOVA parameters.
Fig 3.
Correctness in estimating direction after a single sound emission for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Fig 4.
Correctness in estimating direction after N sound emissions for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Fig 5.
Correctness in estimating distance after a single sound emission for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Fig 6.
Correctness in estimating distance after N sound emissions for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Fig 7.
Certainty in the answer after the 1st sound emission for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Fig 8.
Certainty in the answer after N sound emissions for the tested sound types and participants divided into sighted, totally blind and visually impaired groups.
Table 3.
Single ANOVA parameters calculated for pairings of participant groups.
Fig 9.
Correctness and certainty change after N signal repetitions for all 26 participants.
Fig 10.
Correctness change in distance and direction after N signal repetitions for all 26 participants.
Fig 11.
Left—Average correctness for participants that needed N signal repetitions to provide their final answer.
Area of the circles corresponds to the number of participants that stopped at the given N. Largest circle area corresponds to 12 participants. Right—Average correctness at the Nth repetition after each participant’s final answer was extended to all further repetitions.
Fig 12.
Quartile distribution plots for the ten compared sounds.
Fig 13.
Comparison of correctness in direction and distance estimates for the 10 different sound sources.
Fig 14.
Distribution of participants with the given percentage of correct answers for each sound after smoothing the results with a kernel density estimating function (KDE) for percussive sounds (left) and other sounds (right), in three rows—Overall correctness, distance correctness only, and direction correctness only.
Fig 15.
Correctness change after N signal repetitions for all 26 participants.
Table 4.
Mann-Whitney U Test results for blue noise.
Table 5.
Mann-Whitney U Test results for pink noise.
Table 6.
Mann-Whitney U Test results for 3kHz percussion sound.
Table 7.
Mann-Whitney U Test results for 4kHz percussion sound.
Table 8.
Mann-Whitney U Test results for 5kHz percussion sound.
Fig 16.
Change in correctness for the 9 tested sounds vs the sounds’ subjective aesthetic ranking.
The participant’s own sound was excluded from this ranking.