OBJECTIVE: To check and correlatethe vocal acoustic measures of the glottal and laryngeal characteristics of women, without laryngeal disorders or vocal complaints, after phonation in a glass tube immersed in water (PGTIW). METHODS: Twenty-four women, aged between 18 and 40 years, were divided into2 groups, with 12 in the study group (SG) and 12 in the control group (CG). They pronounced the vowel sound of /a:/, and videolaryngostroboscopy (VLS) was performed before and after the execution of PGTIW in the SG and before and after a period of silence in the CG. Vocal acoustics, hearing perception, and statistical analyses were conducted using the Wilcoxon, Chi-square, and Spearman tests (p<0.05). RESULTS: In the SG, improvement was seen in the smoothed pitch perturbation quotient (sPPQ), voice turbulence index (VTI), shimmer percentage (Shim), and shimmer in dB (ShdB).Improvement of breathiness in RASATIwas seen, and in the VLS, the laryngeal vestibule constriction did not change significantly. CONCLUSION: The PGTIW technique reduced the vibration glottal aperiodicity and noise, with increased harmonic energy and subsequent improvement of the glottal signal. With VLS, the laryngeal vestibule constriction did not change significantly; this suggests that the technique does not cause laryngeal hypertension.
