Table 1. Comparison of the blind expert's performance with that of sighted controls.
| Control sample (n = 6) | Case | Significance test | Estimated percentage of the control population obtaining better JND than the case | Estimated effect size (zCC) | ||||||
| Exp. | Pos. | Mean | SD | JND | t | p | Point | (95% CI) | Point | (95% CI) |
| 1.1 | W75 | 15.3 | 2.8 | 9.4 | −1.95 | 0.054 | 5.43 | (0.017 to 27.82) | −2.107 | (−3.581 to −0.588) |
| W200 | 38.7 | 4.1 | 24.5 | −3.21 | 0.012 | 1.19 | (0.00 to 10.86) | −3.463 | (−5.678 to −1.234) | |
| W400 | 80.9 | 6.9 | 43.0 | −5.09 | 0.0019 | 0.19 | (0.00 to 1.68) | –5.493 | (–8.882 to –2.124) | |
| M75 | 20.2 | 2.7 | 9.3 | –3.74 | 0.0067 | 0.67 | (0.00 to 6.79) | –4.037 | (–6.579 to–1.491) | |
| M200 | 36.5 | 4.5 | 19.0 | –3.60 | 0.0078 | 0.78 | (0.00 to 7.70) | –3.889 | (–6.346 to –1.425) | |
| M400 | 68.9 | 4.7 | 38.0 | –6.09 | 0.00087 | 0.087 | (0.00 to 0.49) | –6.574 | (–10.602 to –2.583) | |
| 1.2 | W75 | 29.6 | 5.5 | 17.1 | –2.10 | 0.045 | 4.46 | (0.006 to 25.09) | –2.273 | (–3.833 to –0.672) |
| W200 | 58.3 | 7.1 | 35.1 | –3.03 | 0.015 | 1.46 | (0.00 to 12.61) | –3.268 | (–5.372 to –1.145) | |
| W400 | 102.5 | 7.9 | 57.5 | –5.27 | 0.0016 | 0.16 | (0.00 to 1.35) | –5.696 | (–9.205 to –2.211) | |
| M75 | 28.2 | 5.2 | 14.4 | –2.46 | 0.029 | 2.87 | (0.00 to 19.56) | –2.654 | (–4.418 to –0.857) | |
| M200 | 47.5 | 4.6 | 27.8 | –3.97 | 0.0054 | 0.53 | (0.00 to 5.48) | –4.283 | (–6.967 to –1.600) | |
| M400 | 78.9 | 6.7 | 46.8 | –4.44 | 0.0034 | 0.34 | (0.00 to 3.42) | –4.791 | (–7.770 to –1.822) | |
| 2.1 | W75 | 15.2 | 2.9 | 9.8 | –1.72 | 0.073 | 7.27 | (0.066 to 32.21) | –1.862 | (–3.212 to –0.462) |
| W200 | 39.2 | 6.3 | 21.7 | –2.57 | 0.025 | 2.50 | (0.00 to 17.97) | –2.778 | (–4.610 to –0.917) | |
| W400 | 69.4 | 6.8 | 42.2 | –3.70 | 0.0070 | 0.70 | (0.00 to 7.01) | –4.000 | (–6.521 to –1.475) | |
| M75 | 18.7 | 3.6 | 9.5 | –2.37 | 0.032 | 3.21 | (0.00 to 20.89) | –2.556 | (–4.266 to –0.810) | |
| M200 | 38.5 | 5.0 | 19.3 | –3.56 | 0.0082 | 0.81 | (0.00 to 8.02) | –3.840 | (–6.269 to –1.404) | |
| M400 | 71.9 | 8.7 | 39.1 | –3.49 | 0.0087 | 0.87 | (0.00 to 8.50) | –3.770 | (–6.159 to –1.372) | |
| 2.2 | W75 | 20.5 | 4.5 | 10.6 | –2.04 | 0.049 | 4.86 | (0.010 to 26.27) | –2.200 | (–3.722 to –0.635) |
| W200 | 45.3 | 5.5 | 26.8 | –3.11 | 0.013 | 1.32 | (0.00 to 11.73) | –3.364 | (–5.522 to –1.189) | |
| W400 | 76.8 | 8.0 | 45.4 | –3.63 | 0.0075 | 0.75 | (0.00 to 7.47) | –3.925 | (–6.403 to –1.442) | |
| M75 | 21.9 | 4.5 | 9.9 | –2.47 | 0.028 | 2.83 | (0.00 to 19.39) | –2.667 | (–4.438 to –0.864) | |
| M200 | 42.1 | 4.9 | 22.9 | –3.63 | 0.0076 | 0.75 | (0.00 to 7.51) | –3.918 | (–6.392 to –1.439) | |
| M400 | 72.1 | 8.3 | 39.8 | –3.60 | 0.0078 | 0.77 | (0.00 to 7.68) | –3.892 | (–6.350 to –1.427) | |
The blind echolocation expert performed better than the sighted subjects in all experimental conditions, especially for large reference distances. The table shows results of a one-tailed t-test analysis (cf. [27]) comparing the performance in terms of JND of the blind echolocation expert with the performance of the six sighted subjects. It includes reporting point and interval estimates of the percentage of the control population obtaining a better JND than the case as described in [28] and for the effect size (zCC) for the differences between case and controls as described in [29].