A Nasoendoscopic Study of "Head Resonance" and "Imposto" in Classical Singing

Classical singing pedagogy uses many concepts which lack precise definition and whose acoustic and physiologic correlates are unclear. This study focuses on the concepts "head resonance" and "imposto." In singing guidebooks, head resonance has been described as causing vibratory sensations on the face and head, auditively it has been described as a bright color especially predominating in the higher pitch range. "Imposto" has been related to the sensation of "air flow" or "sympathetic resonance vibrations" on or over the upper bridge of nose, and it also has been pursued using a "closing mechanism of the upper respiratory track" (activation of nasalis muscle).

Experimental cross-sectional study.

Five subjects (three classical singers, one amateur singer, and a nonsinger) were investigated with nasofiberoscopy during phonation. The singers were instructed to sing [i:] on one comfortable self-chosen pitch in three ways: (1) without head resonance, (2) with head resonance, and (3) using imposto (exploiting the nasalis muscle). The nonsinger was investigated without phonation, while just holding his breath after inhalation first normally and then while producing imposto. The following measurements were made on the fiberoscopic images: (1) height of soft palate, (2) area of the hypopharynx, (3) area of the epilaryngeal tube inlet.

The singers raised the soft palate and narrowed the epilaryngeal inlet during head resonance and even more during imposto. The pharynx to epilarynx ratio increased. Similar narrowing of the epilaryngeal tube inlet was observed in the nonsinger when constricting the nasalis, CONCLUSIONS: The results suggest that both the head resonance and imposto are related to control of the pharyngeal space and epilaryngeal tube, and that the nasal muscles may be used as an aid in regulating the epilaryngeal tube width, which in turn, improves the voice-source -tract interaction.