A pilot investigation of twang quality using magnetic resonance imaging

Background: Twang quality is a bright, piercing quality often produced in contemporary pop/rock/country music, musical theatre singing, and character voices. Despite its potential application to voice therapy and singing pedagogy, limited information is available regarding the exact physiologic underpinnings of twang quality. The purpose of this study was to provide quantitative information regarding three-dimensional (3D) vocal tract configurations of twang quality using magnetic resonance imaging (MRI). Methods: Two participants, with professional singing and pedagogy experience in a variety of singing styles, sustained twang and speech quality on vowel /i/ while lying supine in the MRI scanner. Vocal tract measures included larynx height and velar height in the midsagittal view as well as lateral pharyngeal width, anteroposterior pharyngeal (AP) width, and pharyngeal area in the axial view. Results: When compared to speech /i/, participants produced twang with a smaller pharyngeal area with significant narrowing in the lateral dimension, a slightly elevated laryngeal position, and closed VP port. Of note, Participant 1 also demonstrated significant pharyngeal narrowing in the AP dimension at the oropharyngeal level. Conclusion: The results are consistent with some aspects of previous descriptions of twang but provide further clarification regarding physiologic underpinnings of twang quality for therapeutic and pedagogic application.