Many studies have been carried out on vibrato in the singing voice, though usually on singing of professional singers. In the present study we examine vibrato quality in sustained notes as sung by students, rather than professionals, in an attempt to find objective measures for assessing vibrato quality in singing students. A set of 78 notes was assessed subjectively by 5 experiences musicians. A set of acoustic measures was then extracted, and analyzed statistically to obtain two indicators: presence or absence of vibrato, and in the case of presence – an indication of vibrato quality. Discrimination between presence and absence of vibrato was 82% correct; the predictor of vibrato quality achieved a significant correlation coefficient of 0.7395 with the subjective judgments.