Can blind persons accurately assess body size from the voice?

Abstract

Vocal tract resonances provide reliable information about a speaker's body size that human listeners use for biosocial judgements as well as speech recognition. Although humans can accurately assess men's relative body size from the voice alone, how this ability is acquired remains unknown. In this study, we test the prediction that accurate voice-based size estimation is possible without prior audiovisual experience linking low frequencies to large bodies. Ninety-one healthy congenitally or early blind, late blind and sighted adults (aged 20 -65) participated in the study. On the basis of vowel sounds alone, participants assessed the relative body sizes of male pairs of varying heights. Accuracy of voice-based body size assessments significantly exceeded chance and did not differ among participants who were sighted, or congenitally blind or who had lost their sight later in life. Accuracy increased significantly with relative differences in physical height between men, suggesting that both blind and sighted participants used reliable vocal cues to size (i.e. vocal tract resonances). Our findings demonstrate that prior visual experience is not necessary for accurate body size estimation. This capacity, integral to both nonverbal communication and speech perception, may be present at birth or may generalize from broader cross-modal correspondences.

A house of cards: bias in perception of body size mediates the relationship between voice pitch and perceptions of dominance

“…Formant frequencies cannot explain 85% of the variance in body size among same-sex adults. Here it is important to note that even though voice pitch and formants are both tied to the perception of body size (Collins, 2000;Collins & Missing, 2003;Feinberg et al, 2005;Pisanski, Feinberg, Oleszkiewicz, & Sorokowska, 2017;Pisanski et al, 2014b;Pisanski, Oleszkiewicz, & Sorokowska, 2016;Pisanski & Rendall, 2011;Rendall et al, 2007;Smith & Patterson, 2005), and formants are tied to physical height (Pisanski et al, 2014b), these cues are not used in the same way in many mate-choice relevant decisions (Feinberg et al, 2011;Feinberg et al, 2005;Pisanski & Rendall, 2011;Pisanski et al, 2014c). Furthermore, processing of voice pitch and formants take different neural pathways, where voice pitch processing occurs later, and contributes more to bias in perception of size, whereas formant information is used earlier for acoustic size scaling (von Kriegstein, Warren, Ives, Patterson, & Griffiths, 2006), which aids in vowel perception (Turner, Walters, ` Monaghan, & Patterson, 2009).…”

Voice-based assessments of trustworthiness, competence, and warmth in blind and sighted adults

“…Blind persons can also estimate body size from the voice as accurately as can sighted persons (Pisanski et al, 2016). In line with these previous findings, our study provides novel evidence that blind persons process socially relevant information (i.e., competence and warmth) from nonverbal voice cues similarly to sighted persons.…”

Voice cues are used in a similar way by blind and sighted adults when assessing women’s body size

“…There are several hypotheses regarding how humans attain the ability to estimate body size from the voice. Evidence that infants associate appropriate vocal patterns with size by four months of age 11 , and that blind listeners can estimates men’s relative body sizes with the same degree of accuracy as sighted listeners 12 , suggests that visual experience may not be necessary for accurate voice-based estimation of body size to emerge. In addition, evidence that fundamental and formant frequencies explain only a small portion of variance in height and weight within sexes 10 further suggests that repeated audiovisual pairings of people’s voices with their bodies is unlikely to facilitate accurate size estimation.…”