A study of glottal excitation synthesizers for different voice qualities

•It presented a new glottal excitation synthesizer model.•The new model allows characterizing manifestations of non-linear behavior.•The new model was compared with four widely used glottal excitation models.•The accuracy has lower average global error than the rest of the models.

The aim of this paper is to analyze the improvements that are observed in the glottal excitation synthesizers when the possible manifestations of non-linear behavior are characterized in glottal excitation. This paper proposes a new model based on the modification of a classic glottal excitation synthesizer and to study the improvements regarding different glottal excitation synthesizers. The proposed model tries to improve the naturalness of the synthesized voice using the synthesis of the sub-harmonics. The proposed model is included in a generic synthesizer of sustained vowels in order to get an assessment about the quality of the synthesis of different qualities of voice, where speakers with pathologies in the phonatory system are used to simulate the behavior of low quality voices. The different models are adjusted using genetic algorithms.The assessment of the different glottal excitation synthesizers is obtained using an objective measure of similarity between the original signals and the synthesized signals based on temporal and spectral measurements. In addition, the quality of the proposed glottal excitation model is evaluated with a study of subjective perception.