Effect of Transcranial Direct Current Stimulation on Singers' Voice

Data collection was conducted at the Applied Neuroscience Laboratory (LANA) of the Federal University of Pernambuco (UFPE).

This study includes vocally healthy individuals who are singers without formal music or singing training. Residents of the city of Recife and the Metropolitan Region, aged 18 to 45 years. The age range was chosen considering the period of maximum vocal efficiency To determine the sample size, a pilot study was conducted with 15 participants using the G*Power 3.1 program, considering a statistical power (β) of 80% and a significance level (α) of 5%. For this analysis, the primary vocal outcome variables (vocal range profile) was considered, and the sample size considered was 45, the largest value among the selected outcomes.

Singers without formal music training and without vocal complaints were included.

Individuals who were smokers or who presented signs and symptoms of laryngeal, pharyngeal or respiratory diseases at the time of data collection were excluded from the sample. Volunteers who were using neuroactive medications regularly, have metal implants in the cervical region or above, and had any history of seizures or epilepsy were also excluded.

The sample of singers was constituted by convenience through individuals who were singers without vocal complaints of both sexes, recruited through advertisements in electronic media. The first contact with the volunteers was through a screening to verify the eligibility criteria.