Abstract
Aerodynamic parameters during optimal easy phonation were compared among 6 patients with vocal polyps, 32 patients with glottic cancer (T1 and T2) and 9 normal subjects.
Subglottal pressures (cmH2O) directly extracted by the miniatured pressure tranceducer through the glottis, mean air flow (ml/sec), pitch (Hz) and intensity (dB) of voices, glottal resistance (cmH2O/l/sec), subglottal power (×106 erg/sec), and laryngeal efficiency were obtained with the use of PS-77phonatory equipment and the computerized phonatory system PI-100.
The cases with vocal polyps presented with slightly high values of mean subglottal pressure (the mean value of 9.0cmH2O) and glottal resistance (the mean value of 38.5cmH2O/l/sec) and glottal power 3 times greater than that of the normal subjects. The mean value of laryngeal efficiency was about a half level of that in the normal subjects. In the cases of glottic cancer, the subglotal pressures were inceased to the mean value of 11.6 cmH2O in Tla, 21.7cmH2O in Tlb and 25.7cmH2O in T2 cases respectively. The Glottal resistance and subgottal power were significantly increased by as the T stage became advanced. In contrast, the laryngeal efficiencies decreased as the T stage was advanced : the mean value of 1.27 in T1a, 0.50 in T1b, and 0.25 in T2 cases.
