HSDI of the vocal fold vibrations in healthy young & elderly males and females
Observation of vocal fold (VF) behavior in young females showed posterior gap and posterior-to-anterior longitudinal phase difference while in young males mucosal wave, anterior-to-posterior longitudinal phase difference, and supraglottic hyperactivity were frequent. In elderly females high incidence of lateral phase difference, atrophic change, anterior gap, and asymmetry were observed. In elderly males axis shift, asymmetry, supraglottic hyperactivity, increased mucosal wave, lateral phase difference, and anteriorto-posterior longitudinal phase difference were frequent. VF vibrations are diverse even in healthy subjects, and hence, this diversity must be taken into account in evaluating VF vibrations.