Measurements of the vibrato rate of ten singers

The vibrato rate for ten singers, all singing Schubert’s Ave Maria, was measured on sonograms. Commercially available CD records were used to insure that the vibrato originated in a real musical performance. It was found, that the vibrato rate typically increased at the end of each tone, +15% in average, while no typical structure could be found in the beginning of a tone. Disregarding the increase of vibrato rate toward tone endings, the mean rate across singers was 6.0 Hz. The average variation between maximum and minimum rate within an artist is about ±8% of the artist’s average.