Speech-to-Singing Synthesis: Converting Speaking Voices to Singing Voices by Controlling Acoustic Features Unique to Singing Voices

This paper describes a speech-to-singing synthesis system that can synthesize a singing voice, given a speaking voice reading the lyrics of a song and its musical score. The system is based on the speech manipulation system STRAIGHT and comprises three models controlling three acoustic features unique to singing voices: the fundamental frequency (F0), phoneme duration, and spectrum. Given the musical score and its tempo, the F0 control model generates the F0 contour of the singing voice by controlling four types of F0 fluctuations: overshoot, vibrato, preparation, and fine fluctuation. The duration control model lengthens the duration of each phoneme in the speaking voice by considering the duration of its musical note. The spectral control model converts the spectral envelope of the speaking voice into that of the singing voice by controlling both the singing formant and the amplitude modulation of formants in synchronization with vibrato. Experimental results show that the proposed system can convert speaking voices into singing voices whose naturalness is almost the same as actual singing voices.