and their vibration is periodic. In breathy phonation, tension is low, the overall glottal aperture is increased, the closure of the folds is incomplete and of short duration, the vibratory pulse is symmetrical in shape, and glottal airflow is high, leading to a strong first harmonic and audible frication noise (Laver, 1980; Pennington, 2005; Gobl and Ni Chasaide, 2012). Lax phonation is supposed to have a similar glottal (“slack”) configuration, but less extreme. In contrast, tense or phonation is (or “stiff” “pressed”) characterized by increased adductive tension and medial compression, so that the glottal aperture is reduced and only the ligamental part of the vocal folds vibrates. The closure of the folds is complete and abrupt, and of longer duration, and the pulse shape is skewed, increasing the energy in the higher frequencies. Glottal airflow is low, leading to a weaker first harmonic (Gobl and Ni Chasaide, 2012). Tense phonation may also involve a higher degree of tension in the entire vocal tract, affecting the respiratory system as well as the supralaryngeal tract. Creaky voice is essentially similar, but due to greater tension and possible incursion of the ventricular folds, vibration is irregular (Childers et al., 1990; Gobl and Ni Chasaide, 2012). These descriptions generally suggest that tense and lax phonations are produced quite similarly to creaky and breathy phonations, respectively; however, Figure 1 above suggests that acoustically, they are much more similar to modal phonation, and to each other, than to these extreme non-modal phonations. C. Previous studies of Tibeto-Burman phonation types The acoustic correlates associated with tense vs. lax contrasts in Tibeto-Burman languages have received some attention in the literature. Several studies have identified
and their vibration is periodic. In breathy phonation, tension is low, the overall glottal aperture is increased, the closure of the folds is incomplete and of short duration, the vibratory pulse is symmetrical in shape, and glottal airflow is high, leading to a strong first harmonic and audible frication noise (Laver, 1980; Pennington, 2005; Gobl and Ni Chasaide, 2012). Lax phonation is supposed to have a similar (“slack”) glottal configuration, but less extreme. In contrast, tense (or “stiff” or “pressed”) phonation is characterized by increased adductive tension and medial compression, so that the glottal aperture is reduced and only the ligamental part of the vocal folds vibrates. The closure of the folds is complete and abrupt, and of longer duration, and the pulse shape is skewed, increasing the energy in the higher frequencies. Glottal airflow is low, leading to a weaker first harmonic (Gobl and Ni Chasaide, 2012). Tense phonation may also involve a higher degree of tension in the entire vocal tract, affecting the respiratory system as well as the supralaryngeal tract. Creaky voice is essentially similar, but due to greater tension and possible incursion of the ventricular folds, vibration is irregular (Childers et al., 1990; Gobl and Ni Chasaide, 2012). These descriptions generally suggest that tense and lax phonations are produced quite similarly to creaky and breathy phonations, respectively; however, Figure 1 above suggests that acoustically, they are much more similar to modal phonation, and to each other, than to these extreme non-modal phonations. C. Previous studies of Tibeto-Burman phonation types The acoustic correlates associated with tense vs. lax contrasts in Tibeto-Burman languages have received some attention in the literature. Several studies have identified