Norman · PloS one 2021 · controlled interventional training study · n=?

Human click-based echolocation: Effects of blindness and age, and real-life implications in a 10-week training program.

Cited 61 times in the scientific literature.

Level 3 - non-randomized controlled study

Non-randomized controlled cohort comparison between blind and sighted participants

PubMed 34077457 · doi:10.1371/journal.pone.0252330 · record verified 2026-08-26

What was done

Blind and sighted participants aged 21–79 years (median age: blind 45 years, sighted 26 years) completed 20 training sessions over 10 weeks practicing click-based echolocation across practical and virtual navigation tasks. Blind participants also completed a 3-month follow-up survey evaluating daily-life impacts.

What was found

Both blind and sighted groups improved across all performance measures, with some participants performing comparably to expert echolocators by the end of training. Sighted participants outperformed blind participants on certain tasks, an effect the authors state may be explained by younger age or superior binaural hearing in the sighted group. Neither age nor visual status limited learning rates or transfer to novel, untrained tasks. At 3-month follow-up, 100% of blind participants reported improved mobility, and 83% reported improved independence and wellbeing. The abstract reports no numerical task performance scores.

Why it matters

These findings indicate that click-based echolocation is learnable in adulthood regardless of age or vision loss, supporting its utility in vision rehabilitation programs.

Limits

The abstract omits total sample size and exact task performance values. Groups differed markedly in median age (26 vs. 45 years), confounding vision-based comparisons. Daily-life outcomes relied entirely on self-reported survey data without objective real-world mobility testing.

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