Formant speech synthesis

This paper describes analysis and synthesis methods for a digital formant synthesizer. It is shown that synthetic speech generated using excitation pulses which resemble the true glottal volume-velocity excitation waveform is preferred over speech synthesized using a two pole glottal filter and impulse excitation. A series of algorithms for voice/unvoiced/mixed/silent interval clasification, pitch detection, and formant estimation and racking are described. We have also initiated an investigation into the feasibility of using the digital formant synthesizer to study the acoustic correlates of voice quality. A number of experiments involving male/female voice conversion, and the stimulation of various vocal characteristics, such as breathiness, roughness, and vocal fry, were undertaken. The results have helped to establish the importance of various acoustic features as descriptors of specific voice qualities.