Female Classical Singers Apply Different Resonatory Strategies Than Male: Insights from an MRI-Based Analysis.

Introduction: The morphology of the vocal tract plays a crucial role in singing. Adjustments of the lower part of the vocal tract are essential for voice quality and timbre. Structured investigations of this region are challenging due to the small extent of the morphological modifications.

Material and methods: This study analyzed the morphology of the endolaryngeal tube and parts of the surrounding hypopharynx for the sustained vowels /a/, /e/, /i/, //, and // by 11 female singer subjects who were at the beginning of their academic singing studies. As in a previous study with male subjects, analysis was based on two phonatory conditions: a natural, speech-like phonation and a singing phonation, like in classical singing. By means of 3D image processing from magnetic resonance imaging, multiple measures were derived. The data were statistically analyzed using linear mixed effects models and ANOVA.

Results: The female singers enlarged the ratio of the endolaryngeal tube to the adjacent hypopharynx for singing.

Discussion: In contrast to the findings of the male singers in a previous study, the ratios of the laryngeal volumes to the neighboring hypopharynx increased while singing. The female singer subjects of the present study increased those ratios, mediated by an over-proportional enlargement of the endolaryngeal tube. Existing acoustic differences to male singers are thus given a morphological basis.

Conclusion: The study gives insight into the characteristic adjustments of the vocal tract of female classical singers. The resonatory strategies for females in classical singing differ from those found in males.