Pitch-driven adjustments in tongue positions: Insights from ultrasound imaging

As an important singing technique, trained singers tend to adjust their resonance space based on pitch, especially for higher pitches. The mechanism behind vowel modification remains unclear - is it learned only for certain acoustic goals, or inherently required for articulatory ease? To address this question, we explore whether speakers adjust their resonance spaces when targeting different pitches; and if so, how. 23 participants participated in a production experiment involving ultrasound tongue imaging technique. Participants were asked to sing vowels across their pitch range rising by semitone. Results show that there is a link between pitch range and tongue positional adjustments - participants with a larger pitch range tended to adjust their tongue positions as they reached higher pitches, including some individuals who reported no history of vocal training. We discuss our results with respect to interactions between the source and filter in the human voice production system.