The intensities of vowels and plosive bursts and their impact on text intelligibility in singinga).

In classical singing, there are often problems with the intelligibility of sung text. The present study aims to test the hypotheses that (1) in loud operatic singing, compared with speaking, the intensity of voiceless plosives increases less than the intensity of vowels, leading to poorer recognition of plosives; and (2) pronouncing the plosive bursts with greater intensity improves their recognition. The acoustic analysis of nine opera arias in Italian from the Classical and Romantic periods performed by ten classically trained singers showed that the average difference in the intensity of vowels when sung and spoken was 14.