Preliminary report on a jitter extraction system
E. Thomas Doherty · The Journal of the Acoustical Society of America · 1977
Vocal jitter, the cycle-to-cycle variation in the frequency of vibration of the vocal folds, may be an effective indicator of the operational state of that mechanism. Thus far, calculation of the amount of jitter produced in the laryngeal wave has been a rather tedious process. The jitter extraction system proposed here is based on a special application of the fundamental frequency indicator (FFI) at the Institute for Advanced Study of the Communication Processes. Since the most recent models of FFI are capable of providing a reasonably precise determination of the duration of each cycle (of the glottal source wave), it is possible to modify the computational aspect of that system to measure also the difference in the duration of successive periods. Validation of this approach to vocal jitter analysis is based upon a comparison with a technique using high-speed photography of oscillographic traces reported by H. Hollien, J. Michel and E.T. Doherty [“A method for analyzing vocal jitter in sustained phonation,” J. Phonet. 1, 85–91 (1973)]. Such validation provides evidence that FFI can be utilized as the basis of a rapid and efficient jitter analysis system.