Acoustic Correlates of Glottal Opening

 

Corinne Cabral

Dept. of Communication Sciences and Disorders

Valdosta State University

 

 

PURPOSE:  The purpose of this study was to compare acoustic correlates of vocal fold function between young female smokers and nonsmokers.

METHODS:  Ten young adult female non-smokers and ten young adult female smokers, ranging in age from 18 to 28 years participated in this study. Voice recordings consisted of three trials of the vowel /æ/, produced at a comfortable pitch and loudness level.  Measurements included the following, as described by Hanson (1997): (1) H1*-H2*, the ratio of the amplitude of the first harmonic to the amplitude of the second harmonic, which is associated with open phase; (2) H1*-A1, the ratio of the amplitude of the first harmonic to the amplitude of the first formant frequency, which is associated with glottal closure; and (3) H1*-A3*, the ratio of the amplitude of the first harmonic to the amplitude of the third formant frequency, which is associated with alterations in spectral tilt, e.g., speed of vocal fold closure.  Fundamental frequency (F0) and relative loudness level (RLL) were also obtained.

RESULTS:  The results of this study demonstrated a significant difference in the spectral measure of H1*-A3*. There was no significant difference found for F0, RLL, H1*-H2*, or H1*-A1.

CONCLUSIONS:  The results from this study suggest that smoking may affect vocal fold function in young females.  These changes in vocal fold function may be measured by spectral correlates of glottal function. There was a significant difference indicated in the spectral measure of spectral tilt H1*-A3*, indicating a reduction in closing speed of the vocal folds during phonation.  This slower closing speed is likely related to an increase in vocal fold mass.