On the interdependencies between voice quality, glottal gaps, and voice-source related acoustic measures

In human speech production, the voice source contains important non-lexical information, especially relating to a speaker’s voice quality. In this study, direct measurements of the glottal area waveforms were used to examine the effects of voice quality and glottal gaps on voice source model parameters and various acoustic measures. Results showed that the open quotient parameter, cepstral peak prominence (CPP) and most spectral tilt measures were affected by both voice quality and glottal gaps, while the asymmetry parameter was predominantly affected by voice quality, especially of the breathy type. This was also the case with the harmonic-to-noise ratio measures, indicating the presence of more spectral noise for breathy phonations. Analysis showed that the acoustic measureH1 −H2 was correlated with both the open quotient and asymmetry source parameters, which agrees with existing theoretical studies.