Analysing changing vibrato behaviour in solo voice ensemble singing: Pan European Voice Conference

Perceptually vibrato is known to be an important characteristic in choral singing, with conductors specifically directing singers in their use of vibrato when considering "choral blend", tuning, expression and taste. Particularly in Renaissance and Baroque repertoire vibrato is conventionally used as an ornament, and current convention in vocal ensemble performance is to restrict the use of vibrato for musical affect at specific moments in the music, such as at the resolution of a suspension. Whilst vibrato in solo singing is well-researched, consideration of vibrato behaviour of individuals in an ensemble setting is still in its infancy. This is in part due to the difficulty of isolating the individual voices for analysis.
In order to construct a method for analysing vocal characteristics of individual singers within a group, a protocol was designed and pilot tested. Laryngograph and audio recordings were made of student vocal quartets from the University of York. The laryngograph data for each singer was analysed to extract fundamental frequency data. The fundamental frequency data was then used to analyse vibrato characteristics of the individual singers, considering in particular adapting vibrato for "choral blend" and the use of vibrato as a musical ornament in suspensions. The perceptual relevance of the vibrato behaviour was assessed through a listening test. The results of vibrato characteristics of individual singers are considered alongside their perceptual relevance. The accuracy of the data is also considered alongside the implications of applying this protocol to analyse other vocal characteristics in choral singers.