Can blind persons accurately assess body size from the voice?
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.
Institute of Psychology, University of Wroclaw, Wroclaw, Poland Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Sussex, UK k.pisanski@sussex.ac.uk.
Katarzyna
http://orcid.org/0000-0003-0992-2477
K
Pisanski
Institute of Psychology, University of Wroclaw, Wroclaw, Poland.
Anna
A
Oleszkiewicz
Institute of Psychology, University of Wroclaw, Wroclaw, Poland Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany.
Agnieszka
A
Sorokowska
D000328:Adult; D000368:Aged; D001766:Blindness / Q000503:physiopathology* / Q000523:psychology; D049628:Body Size; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013061:Speech Acoustics; D013067:Speech Perception / Q000502:physiology*; D019987:Persons with Visual Disabilities; D014831:Voice / Q000502:physiology*
congenital blindness; formant; height; size normalization; visual impairment; vocal communication