Photobiomodulation in Muscle Tension Dysphonia: A Pilot Study

To evaluate the immediate and medium-term effect of photobiomodulation on self-perceived vocal fatigue and acoustic, perceptual, and laryngeal parameters in professional voice users with primary muscle tension dysphonia.

Fifteen professional voice users with primary muscle tension dysphonia and complaints of vocal fatigue were randomly assigned to a test group (TG) and a control group (CG) for a pilot, longitudinal, prospective, randomized, comparative study. TG received photobiomodulation at specific points on the thyroid cartilage laminae, and CG received placebo photobiomodulation at the same sites and for the same duration as the TG. The assessments included the Vocal Fatigue Index (VFI), acoustic assessment by the Acoustic Voice Quality Index (AVQI), auditory-perceptual evaluation, and videolaryngostroboscopy. The groups were evaluated at baseline, immediately after the first intervention, and after the fourth session.

No statistically significant differences were observed between groups or over time for any of the evaluated outcomes.

Photobiomodulation applied alone under the investigated parameters did not produce immediate or short-term effects in professional voice users with primary muscle tension dysphonia.