Body Perception From Connected Speech: Speaker Height Discrimination from Natural Sentences and Sine-Wave Replicas with and without Pitch.

In addition to language, the human voice carries information about the physical characteristics of speakers, including their body size (height and weight). The fundamental speaking frequency, perceived as voice pitch, and the formant frequencies, or resonators of the vocal tract, are the acoustic speech parameters that have been most intensely studied for perceiving a speaker's body size. In this study, we created sine-wave (SW) replicas of connected speech (sentences) uttered by 20 male and 20 female speakers, consisting of three time-varying sinusoidal waves matching the frequency pattern of the first three formants of each sentence. These stimuli only provide information about the formant frequencies of a speech signal. We also created a new experimental condition by adding a sinusoidal replica of the voice pitch of each sentence. Results obtained from a binary discrimination task revealed that (a) our SW replicas provided sufficient useful information to accurately judge the speakers' body height at an above chance level; (b) adding the sinusoidal replica about the voice pitch did not significantly increase accuracy; and (c) stimuli from female speakers were more informative for body height detection and allowed higher perceptual accuracy, due to a stronger correlation between formant frequencies and actual body height than stimuli from male speakers.