The impact of phonation mode and vocal technique on vocal fold closure in young females with normal voice quality.

OBJECTIVE

Because voice quality depends substantially on vocal fold closure (VFC), voice therapists try to modify VFC by specific voice techniques or adjustments in phonation mode. This study demonstrates the impact of six different phonation modes on VFC in healthy subjects.

METHODS

For this study, 21 female subjects with normal voice quality were selected. The impact of different phonation modes and voice techniques was examined by fiberoptic laryngovideoendoscopy during different modes of phonation: habitual phonation, high pitch, low pitch, resonance on /m/, Coblenzer's "abspannen," and chant talk. The video recordings were judged by three experienced professionals (two Speech and Language Pathologist and one laryngologist) by means of a visual analog scale.

RESULTS

Statistical analysis showed that only resonance on /m/ significantly improved VFC compared with habitual phonation. All other phonation modes and techniques, except low-pitched phonation, led to a significant worse closure in comparison with the closure at normal pitch. The glottic closure observed by low-pitched phonation was not significantly different than the closure at habitual pitch. Interrater agreement was moderate to very good, depending on the mode of phonation.

CONCLUSIONS

The results of this study allow a better understanding of the impact of phonation mode and vocal therapy techniques on VFC in healthy subjects and give an indication about the impact of these methods to influence VFC.