Objectives This study aimed to investigate whether humming affects the adductive motion of
the vocal folds and transient glottal closure in the prephonatory adjustment phase of vocal
onset using high-speed digital imaging (HSDI) and a motion analysis software program.
Methods Twenty normal healthy adults without any vocal abnormalities were enrolled. While
a transnasal flexible fiberscope connected to a high-speed camera was inserted, each
participant was asked to perform three phonatory tasks—natural/e:/phonation …