Changes After Voice Therapy in Acoustic Voice Analysis of Chinese Patients With Voice Disorders

Objectives. This study aimed to evaluate the effects of voice therapy on patients with voice disorders by comparing the acoustic parameter changes before and after treatment. Study Design. This is a retrospective study. Methods. Forty-five female patients with early-stage vocal nodules or polyps, postoperative patients, and patients with chronic laryngitis were divided into three subgroups. Videostroboscopic, acoustic analysis (fundamental frequency, jitter, shimmer, mean harmonics-to-noise ratio), and maximum phonation time (MPT) were measured before and after treatment, Fifty healthy female volunteers were the control group. Results. After treatment, 24.4% of nodules or polyps had decreased in size, 11.1% of patients with chronic laryngitis and postoperative patients had reduced edema, and the mucosal wave of vocal folds had different degrees of recovery in postoperative patients, All acoustic analysis values and MPT in the patient group were statistically worse than in the control group, except for fundamental frequency before treatment (P > 0.05). After treatment, the acoustic analysis and MPT values were improved. However, the jitter, mean harmonics-to-noise ratio, and MPT values in the patient group were still worse after voice therapy than in the control group (P < 0,05). Conclusions. Most of acoustic analysis values can be useful as a complementary tool in diagnosis and assessment of voice disorders; however, it is not recommended to use a single parameter to assess voice quality. Voice therapy can improve voice quality in patients with voice disorders, hut a period longer than 8 weeks is recommended for these patients.