Acoustical properties of the vocal-tract in trombone performance

The study of the acoustical in uence of the upstream (vocal-tract) airway in wind instrument performance has been a growing subject of interest in musical acoustics. In a recent study performed on trombone players, we observed a noticeable increase of the acoustic pressure near the fundamental frequency at the input of the vocal tract relative to the acoustic pressure at the input of the instrument with increase in pitch. Upstream pressure particularly overtook downstream pressure amplitude for tones above the theoretical cut-o frequency of the air column (around 700 Hz), as well as in pitch bends for which players sound a tone on the lower side of an input impedance peak of the air-column. Overall, these observations suggest that vocal-tract manipulations may be used for upstream tuning in supporting the oscillation of the lips when the magnitude of the downstream input impedance is low enough. However, these results did not provide any evidence of a consistent adjustment of vocal tract input impedance during these tasks. In this study, we evaluate the amplitude of vocal-tract input impedance in trombone performance from upstream and downstream pressure spectra and measurements of the input impedance of a trombone. Measurements are conducted during high pitches, pitch bends, as well as timbre manipulations. We evaluate the consistency of vocal-tract impedance magnitudes across subjects with the aim of identifying whether a vocal-tract tuning occurs during these speci c tasks.