Effects of Mechanical Vibration Stimulus Associated With Vocal Excercises on Laryngeal, Acoustic, and Auditory-Perceptual Parameters.

Abstract

Objectives: To evaluate the immediate effects of mechanical vibration stimulation (MVS) (G-Life NL 3000 device) applied to the larynx along with nasal sound emission immediately after an intervention session.

Methods: In total, 62 subjects of both sexes, aged 18 to 45 years, vocally healthy, and divided into two groups: Experimental Group (EG), which performed nasal sound exercises associated with vibratory stimuli (portable device manufactured by G-Life, model NL 3000-120-Hz frequency and approximately 1-mm displacement amplitude) for 6 minutes; and Control Group (CG), which only performed the nasal sound exercise protocol for 6 minutes. The subjects were evaluated with voice recording and laryngeal assessment before and immediately after the intervention, with the analysis of telelaryngoscopy videos, stroboscopy acoustic parameters, and auditory-perceptual evaluation. The significance value was set at P value < 0.05 for statistical analysis.

Results: Laryngostroboscopic evaluation showed a statistically significant improvement in the EG (P value: 0.002). The maximum phonation time increased significantly in both sexes (men: P value < 0.001, and women: P value 0.008) in the EG. The vocal range increased significantly in EG men (P value < 0.001) and women (P value < 0.001). In acoustic parameters, a significant reduction in jitter (P value < 0.001) and shimmer (P value < 0.001) was observed in both sexes in the EG. An increase in F0 was also noted for men in both groups (EG: P value < 0.001, and CG: P value 0.033). Spectrogram and auditory-perceptual evaluation were not sensitive enough to detect significant changes, although they were better in the EG.

Conclusions: The immediate effects of mechanical vibration stimulation associated with nasal vocal sound exercises improved laryngeal and acoustic vocal production parameters.