The abduction quotient related to vocal quality

The abduction quotient, a measure of effective glottal width, was obtained for electroglottographic recordings from a professional operatic baritone singer. The subject produced repeated tokens of the voice qualities breathy, normal, and pressed (or constricted) in both a speech and a singing manner. In the singing manner, the subject produced the three vocal qualities at three pitch levels and three loudness levels. The abduction quotient decreased from breathy to pressed voice, suggesting that the measure corresponds to effective glottal width. The measure was found to be consistently low during all conditions of singing, suggesting that the subject produced all singing tokens with relatively strong laryngeal adduction at the vocal process level. Although the results of this study support the validity and usefulness of the abduction quotient, further verification is needed.     

Glottal airflow and electroglottographic measures of vocal function at multiple intensities

Ten normal female subjects produced syllables at 5 dB increments from soft to loud. The differentiated electroglottogram (dEGG) open and speed quotients were compared to similar quotients from the inverse-filtered airflow waveform. The latter were measured according to objective and subjective criteria. The data indicate that the open quotient from the airflow waveform decreased as the intensity increased. The dEGG open quotient did not demonstrate this trend. The speed quotient from airflow increased initially with vocal intensity and decreased again as the intensity ceiling was approached. The ratio of closing to opening slopes calculated from peaks in the dEGG signal followed a similar pattern. While the trends across intensity conditions were found to correspond for several of the measures, the absolute values obtained using the different methodologies were not comparable.     

Soft Phonation in the Male Singing Voice: A Preliminary Study

Sustained high notes, diminishing gradually from the loudest to the softest phonation within a maneuver called messa di voce, are examined in two contrasting professional tenor voices. Signals of the sound pressure level, electroglottograph, and mean esophageal pressure are recorded, and similar maneuvers by the same subjects are examined stroboscopically. The lyric voice is found to make a gradual diminuendo while maintaining nearly constant posture of the vocal tract together with a phase of complete closure in the glottal cycle. The robust voice, by contrast, passes abruptly from a production of high subglottal pressure and a high closed quotient to one of low pressure and incomplete closure, and the transition is marked by a sudden opening of the previously constricted laryngeal collar. It is proposed that the mode of soft voice production demonstrated by the robust voice be recognized as a distinct register of the singing voice.     

Measurement of Characteristic Leap Interval Between Chest and Falsetto Registers

A markedly smaller time constant distinguishes a chest-falsetto leap from the more usual execution of a sung interval by muscular adjustments in the length and tension of the vocal folds. The features of such a chest-falsetto leap are examined in detail with respect to F0, peak-to-peak amplitude of the vocal-fold contact area signal (EGG), and the closed quotient. A method is proposed to standardize and quantify this chest-falsetto leap in the characteristic leap interval (CLI), a measure of the separation between the natural registers in a given singing voice. The measure is applied to a varied group of experienced singers. Preliminary results include a suggested dimorphic pattern with respect to sex, with female voices exhibiting smaller CLIs and less individual diversity than male voices.