Automated evaluation of singers´ vibrato through time and frequency analysis of the pitch contour using the DSK6713

Vibrato is a musical effect produced in singing and in playing of musical instruments, serving to enrich the musical sound. It is defined as a periodic change of the fundamental frequency (the perceptual correlate, "pitch", is often used interchangeably), and is used to add expression and vocal-like qualities to instrumental music. Empirically, vibrato commonly has a periodicity of 4-8 Hz. Attaining good vibrato in the singing voice requires prolonged training by professional singing coaches. Moreover, while prominent singers\´ vibrato is easily distinguishable, this is not the case for beginners. Indeed, the main algorithmic challenge in evaluating singing qualities regards the fact that judging vibrato quality and even presence is rather subjective, and depends to some extent on the listener. This paper presents a tool to analyze the vibrato of singing students, assisting singing practice and self study. Experimental results and a real-time DSP based implementation of the algorithm will be presented.