The singer's formant has been found to be an important acoustic characteristic of professional operatic altos, tenors, baritones and basses, while it seems unclear whether or not sopranos possess it. According to Dmitriev & Kiselev (1 979) the JFequencies of the "high singing formant" increases @om lower voices to higher voices. By means of a listening test with synthesised vowel stimuli we examined how important the center JFequency of the singer's formant is to voice classijication. The results showed that it clearly influenced voice classijication. In another listening test with synthesised vowel stimuli we examined if a singer's formant belongs to the typical characteristics of a soprano voice. The results showed that increasing the center JFequency of the singer's formant up to 3.4 kHz increased the perceived quality of the soprano synthesis. For the stimulus containing the highest pitches, a synthesis lacking a singer's formant was preferred, while for other stimuli the results were less clear. The frequency relationships between the lower formants and the spectrum partials, especially for theJirst and last tone of a scale, also seem to be relevant for the quality rating of the soprano synthesis.