Institute of Psychology, University of Wroclaw, Wroclaw, Poland.
Mammal Vocal Communication and Cognition Research Group, University of Sussex, Brighton, UK.
Sci Rep. 2017 Sep 4;7(1):10329. doi: 10.1038/s41598-017-10470-3.
Humans' ability to gauge another person's body size from their voice alone may serve multiple functions ranging from threat assessment to speaker normalization. However, how this ability is acquired remains unknown. In two experiments we tested whether sighted, congenitally blind and late blind adults could accurately judge the relative heights of women from paired voice stimuli, and importantly, whether errors in size estimation varied with task difficulty across groups. Both blind (n = 56) and sighted (n = 61) listeners correctly judged women's relative heights on approximately 70% of low difficulty trials, corroborating previous findings for judging men's heights. However, accuracy dropped to chance levels for intermediate difficulty trials and to 25% for high difficulty trials, regardless of the listener's sightedness, duration of vision loss, sex, or age. Thus, blind adults estimated women's height with the same degree of accuracy, but also the same pattern of errors, as did sighted controls. Our findings provide further evidence that visual experience is not necessary for accurate body size estimation. Rather, both blind and sighted listeners appear to follow a general rule, mapping low auditory frequencies to largeness across a range of contexts. This sound-size mapping emerges without visual experience, and is likely very important for humans.
人类仅凭声音就能估算出另一个人的体型大小，这种能力可能具有多种功能，从威胁评估到说话者正常化。然而，这种能力是如何获得的仍然未知。在两项实验中，我们测试了视力正常、先天性失明和后天失明的成年人是否能够准确地从配对的声音刺激中判断女性的相对身高，重要的是，在不同难度的任务中，大小估计的误差是否会因群体而异。盲人和视力正常的听众（分别为 n=56 和 n=61）在大约 70%的低难度试验中正确判断了女性的相对身高，这与之前判断男性身高的结果相符。然而，对于中等难度的试验，准确性降至随机水平，对于高难度的试验，准确性降至 25%，而与听众的视力、视力丧失的持续时间、性别或年龄无关。因此，失明的成年人在估计女性身高时，与视力正常的对照组一样，具有相同的准确性和相同的错误模式。我们的研究结果进一步证明，视觉体验并不是准确估计身体大小所必需的。相反，盲人和视力正常的听众似乎都遵循一个一般规则，即在各种情况下，将低频声音映射到大小上。这种声音大小的映射是在没有视觉体验的情况下出现的，对人类来说可能非常重要。
