A comparative study of glottal open quotient estimation techniques
John Kane, Stefan J. Scherer, Louis‐Philippe Morency, Christer Gobl · 2013
The robust and efficient extraction of features related to the glottal excitation source has become increasingly important for speech technology. The glottal open quotient (OQ) is one rel-evant measurement which is known to significantly vary with changes in voice quality on a breathy to tense continuum. The extraction of OQ, however, is hampered in the time-domain by the difficulty in consistently locating the point of glottal open-ing as well the computational load of its measurement. De-termining OQ correlates in the frequency domain is an attrac-tive alternative, however the lower frequencies of glottal source spectrum are also affected by other aspects of the glottal pulse shape thereby precluding closed-form solutions and straightfor-ward mappings. The present study provides a comparison of three OQ estimation methods and shows a new method based on spectral features and artificial neural networks to outperform existing methods in terms of discrimination of voice quality, lower error values on a large volume of speech data and dra-matically reduced computation time.