Vocal inharmonicity analysis: A promising approach for acoustic screening for dysphonia.

Abstract

In the United States, 6.8% of men, women, and children report voice problems currently, while during their lifetime ca. 29% will complain of some dysphonia, often due to pathologies of the vocal folds. The authors (a physicist and a speech pathologist) describe an interdisciplinary approach that exhibits promise for detecting physiological abnormalities of the vocal folds from a spectral analysis of the overtone series of spoken tokens. This preliminary investigation shows that the normal human vocal fold emits overtones that are very nearly precise integral values of the fundamental. Physiological problems of the vocal folds, however, introduce mechanical nonlinearities that manifest themselves as frequency deviations from the ideal harmonic (that is, integral) values. The authors quantify this inharmonicity, describing and illustrating how one can efficiently obtain and analyze such data. They outline, as well, a proposed investigation to assess the clinical sensitivity and significance of the analysis discussed in this work in conjunction with laryngoscopic diagnosis of pathology.

Toward a quantitative account of pitch distribution in spontaneous narrative: Method and validation

“…The fundamental frequency F 0 , a meaningful index of the pitch of a complex tone , is often used as the metric for pitch in intonation studies (Rietveld and Gussenhoven, 1985). In fact, Matteson and Lu found a remarkably harmonic spectrum, by use of precision spectral analysis of the overtone series of vowels for typically healthy human voices that often exhibited over 100 frequency components separated by the fundamental frequency and therefore was uniquely characterized by the F 0 of the series (Matteson and Lu, 2009). Other researchers in intonational studies have opted for the use of mel (or the ERB scale) that was introduced initially to map the pitch of pure tones onto the position of the stimulus on the Basilar membrane of the cochlea (Stevens et al, 1937).…”