Vocal shimmer during sustained phonation was measured in normal subjects and patients with laryngeal polyps, using the mean amplitude difference between consecutive cycles expressed in dB. A small laboratory computer was then used for measuring each discrete amplitude and for data processing. The results showed some overlap between the values for two groups studied, but nevertheless it appears that the measured value may be a useful index in screening for laryngeal disorders and for definitive diagnosis of such disorders.
HeckerMHLKreulEJ: Description of the speech of patients with cancer of the vocal folds. Part 1: Measures of fundamental frequency. J Acoust Soc Am49: 1275–1232, 1971
5.
HollienHMichelJDohertyET: A method for analyzing vocal jitter in sustained phonation. J Phonetics1: 85–91, 1973
6.
KoikeY: Vowel amplitude modulation in patients with laryngeal diseases. J Acoust Soc Am45: 839–844, 1969
7.
CrystalTHJacksonCL: Extracting and processing vocal pitch for laryngeal detection. J Acoust Soc Am48: 118, 1970
8.
WendahlRW: Laryngeal analog synthesis of jitter and shimmer. Auditory parameters of harshness. Folia Phoniatr18: 98–108, 1966
