[Objective description of voice quality using the hoarseness diagram]

The need for an objective assessment of voice quality can be seen in the increasing use of acoustic analysis methods for clinical diagnosis and research. The hoarseness diagram allows clinicians to objectively describe even highly disturbed or aphonic votes. Its application possibilities are illustrated in three case studies in which changes in voice quality were monitored during voice rehabilitation. The distributions of voice groups that were defined on the basis of specific pathophysiological phonation conditions were then compared for their acoustic differences. The groups comprised various phonation conditions after the resection of laryngeal tumors and different types of laryngeal paralyses. Interpretation of the results suggests a direct correspondence of the hoarseness diagram coordinates and the irregularity of vibration on the one side and the degree of glottal closure on the other. This illustrates the potential usefulness of the hoarseness diagram in a clinical context.