Acoustic voice quality description: Case studies for different regions of the hoarseness diagram

The hoarseness diagram supplies a method to quantitatively describe the periodicity and the noise content of voices. It is based on four acoustic measures, three of which assess different aspects of periodicity (jitter, shimmer, mean period correlation) while one indicates the relative amount of additive noise (glottal to noise excitation ratio). The behavior of these measures is discussed in detail for four examples of voices found in different regions of the hoarseness diagram. The values obtained are consistent with the theoretical considerations that led to the design of the hoarseness diagram which confirms its reliability. Additionally, the necessity is demonstrated to apply a parabolic interpolation for the waveform matching algorithm that is used to determine the glottal cycle length.