Voiced High-frequency Oscillation and LaxVox: Analysis of Their Immediate Effects in Subjects With Healthy Voice

Abstract

The aim of this study was to analyze the immediate effects of voiced high-frequency oscillation (VHFO) and LaxVox exercises in vocally healthy subjects. Thirty adult subjects (15 women, 15 men) with no history of dysphonia or vocal complaints participated in the study. The subjects performed VHFO and LaxVox techniques for 3 minutes in a random order, with a washout period of 7 days. They answered a questionnaire for vocal/laryngeal intensity symptoms, and had maximum phonation time (MPT) /a/, /s/, /z/, and number counting measured. The vowel /a/ was also recorded before and after both techniques for acoustic analysis. After both techniques, the subjects answered a questionnaire about vocal, laryngeal, respiratory, and articulatory sensations. Data were analyzed using the Wilcoxon, and paired t and chi-square tests were used (P < 0.05), as required. There was an increase in high loudness symptom after LaxVox in women, whereas there was a decrease in painful throat, irritated throat, and low loudness symptoms after VHFO in men. After LaxVox, the MPT of /z/ increased in women and after VHFO, the MPT of /s/, /z/, and number counting increased in men. The fundamental frequency variability increased in women after VHFO. The sensations remained unchanged in both groups following the two exercises in women and men. VHFO and LaxVox techniques had similar effects on vocal and laryngeal symptoms, as a matter of fact, in terms of phonatory and acoustic measures. With regard to vocal symptoms, VHFO showed better immediate effects in men than in women. As a result, the hypothesis H0 is partially refuted.