Dark tone quality and vocal tract shaping in soprano song production: Insights from real-time MRI

Abstract

Tone quality termed “dark” is an aesthetically important property of Western classical voice performance and has been associated with lowered formant frequencies, lowered larynx, and widened pharynx. The present study uses real-time magnetic resonance imaging with synchronous audio recordings to investigate dark tone quality in four professionally trained sopranos with enhanced ecological validity and a relatively complete view of the vocal tract. Findings differ from traditional accounts, indicating that labial narrowing may be the primary driver of dark tone quality across performers, while many other aspects of vocal tract shaping are shown to differ significantly in a performer-specific way.

An open-source toolbox for measuring vocal tract shape from real-time magnetic resonance images

“…It is frequently applied by speech scientists to study movements of the internal structures of the head that shape speech sounds, which are not easily amenable to external observation. The technique has been used to study a broad range of behaviours including the articulatory movements of speech (Belyk et al, 2019 ; Carey et al, 2017 ; Carignan et al, 2020 ; Miller et al, 2014 ; Narayanan et al, 2014 ; Wiltshire et al, 2021 ), vocal registers of singers (Echternach et al, 2010 ; Lynn et al, 2021 ), and vocal expressions of emotion (Belyk & McGettigan, 2022 ), as well as non-speech movements such as swallowing (Mills et al, 2020 ; Olthoff et al, 2014 ; Zhang et al, 2012 ) and beat-boxing (Proctor et al, 2013 ). In typical uses of the technique, a single mid-sagittal slice through the head and neck forms an image that transects the vocal tract (see Fig.…”