Abstract:

This paper describes an ongoing investigation on various extended vocal effects, assisted by personal computer, for the application in contemporary music. Phenomena of co-oscillation between the vocal folds and other structures may cause amplitude modulation on a quasi-periodic glottal signal, thus establishing subharmonics and their integer partials. By means of computer-aided analysis, relevant aspects of several types of phonation may be revealed, complemented by physiological and aerodynamical measurement methods. Such phenomena may include the participation of the false vocal folds (vocal-ventricular mode, VVM, found in Tibetan and Mongolian chants), epiglottis (vocal growl, used in Jazz and Pop music), and segregated mass-spring subsystems within the vocal folds (hypothesised in the case of vocal fry or creaky voice). In addition, cases of biphonation (diplophonia), where the pair of vocal folds oscillates at two or more different frequencies are considered. Computer-aided analysis is shown to be an efficient and inexpensive platform for such study, providing interesting data for voice modelling, music performance and compositional applications.