Practical high-quality speech and voice synthesis using fixed frame rate ABS/OLA sinusoidal modeling

This paper describes algorithms developed to apply the analysis-by-synthesis/overlap-add (ABS/OLA) sinusoidal modeling system to real-time speech and singing voice synthesis. As originally proposed, the ABS/OLA system is limited to unidirectional time-scaling, and relies on variable frame length to accomplish time-scale modification. For speech and voice synthesis applications, unidirectional time scaling makes effective looping to produce sustained vocal sounds difficult, and variable frame length makes real-time polyphonic synthesis problematic. This paper presents a reformulation of the basic ABS/OLA system to deal with these issues, which is termed fixed-rate ABS/OLA (ABS/OLA-FR)