On the Effects of Various Vocal Training Methods on Glottal Resistance and Efficiency

Abstract

The glottal resistance, i.e. the ratio of subglottic pressure to glottal flow, and the laryngeal efficiency, i.e. the ratio of oral acoustic power to aerodynamic subglottal power (multiplication ofsubglottig pressure and glottal flow), were measured for 11 subjects (3 males) with normal voices and for 1 female patient with glottal insufficiency in the repeated production of the nonsense word /paappa/ immediately before and after 1 min of vocal exercising with /β:, m:/ and phonation into a narrow glass tube. For the subjects with normal voices the glottal resistance decreased in most cases and the laryngeal efficiency in half of the cases due to increased glottal flow. In contrast, for the patient the glottal resistance and efficiency increased due to decreased glottal flow. The results suggest that the vocal exercises instantly affected the control of the glottal width.

The Effect of an Artificially Lengthened Vocal Tract on Estimated Glottal Contact Quotient in Untrained Male Voices

“…which would change the measured value of the CQ. This phenomenon was observed in prior studies regarding tube phonation and bilabial fricatives [13][14][15] and suggested as a possible cause of variation in glottal closure data. If changes in laryngeal height were a cause of CQ changes in this study, it is likely that they were due to highly variable and individual responses to an unfamiliar task, as with the changes in vocal fold adduction.…”

“…23 -25 There have been several studies designed to examine the effects of an artificial extension of the vocal tract on the voice. 1,14,15,17,19,27 Baken and Orlikoff 27 reported a transient drop in F 0 for five normal participants when the impedance of a tube coupled to the lips was suddenly changed, indicating an interaction between the control of the voice source and changes in impedance of an artificially lengthened vocal tract. Rothenberg 19 conducted a similar experiment with two professional sopranos, and reported a reduction in EGG (electroglottography) amplitude roughly proportional to the degree of lowering of F1 as a 10 cm tube was coupled to the vocal tract during sung phonation.…”

“…Laukkanen et al have conducted several research studies involving the use of resonance tubes, 1,14,15,17 with both male and female participants phonating into resonance tubes of varying lengths and diameters. Changes in several different variables both during and after tube phonation were reported across these studies, including glottal waveform shape, laryngeal height, glottal efficiency, laryngeal resistance, and perceived vocal effort.…”

Phonation into a Tube as a Voice Training Method: Acoustic and Physiologic Observations

“…It seems like ly that the differences found between the gen ders were incidental. Neither could Laukkanen et al [15] find any differences between the genders in changes of the glottal resistance after various vocal exercises including phona tion into a resonance tube. Although Fo and SPL were kept constant, the glottal resistance decreased for most subjects after tube phona tion due to increased glottal flow, which sug gests decreased adductory force as the in crease observed in subglottic pressure was very small.…”

Immediate effects of the phonation into a straw exercise

“…There were more positive results in the GL than in the GSL (p 0.015), indicating that phonation exercises into a straw could be included in voice training, voice therapy, and voice warm-up programs [8][9][10] . Subjects are expected to perceive how to produce voice economically, using it is common speech and singing -in voice producing conditions that differ from those during exercises.…”