Correlations between vocal tract parameters and body heights in adult humans

Acoustic reflection technology was used to measure the vocal tract morphometric data of 61 adult male subjects and 63 adult female subjects, aged 20-30 years. The relationships between heights and eight vocal tract parameters, including oral length, pharyngeal length, vocal tract length, ratio of oral length to pharyngeal length, oral volume, pharyngeal volume, vocal tract volume and ratio of oral volume to pharyngeal volume, were investigated. Sex differences were found for the correlations between vocal tract parameters and heights. Specifically, for adult males, there were significant positive correlations between height and both pharyngeal volume and vocal tract volume, while for adult females, the height correlated with both vocal tract length and vocal tract volume significantly and positively. These differences probably result from the different patterns of vocal tract growth between males and females at puberty. These findings provide theoretical supports for the estimation of unknown speaker´s height based on voices in forensic phonetics.