Effects of Mechanical Vibration Stimulus Associated With Vocal Excercises on Laryngeal, Acoustic, and...

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.

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.

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.

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