Application of Some Acoustic Measures for the Evaluation of Laryngeal Dysfunction

Perturbation of pitch period and fluctuation amplitude of voice were studied both on normal subjects and on patients with laryngeal diseases. Sound was extracted during vowel phonation by a contact micropohone through the skin and pretracheal tissues. Special attention was paid to the initial period of phonation; the data from this period were compared with those of steady periods of phonation. The investigations indicate marked perturbation of pitch and considerable fluctuation of amplitude exist in the initial period. These findings are closely related to the type of initiation. Fundamental frequency also affected the pitch perturbation and amplitude fluctuation. Pathologic cases showed different values according to the degree and nature of the laryngeal involvement in the disease process. The potential and limitatation of applying these measures for screening and evaluating laryngeal disorders are discussed.