Voice Therapy Effect on Mutational Falsetto Patients: A Vocal Aerodynamic Study

Abstract

The study aims to evaluate the effectiveness of voice therapy (VT) and analyze the vocal aerodynamic characteristics in mutational falsetto (MF) patients. From October 2010 through May 2014, 26 patients with MF at Sun Yat-sen Memorial Hospital were studied retrospectively. Vocal assessment, including the 10-item Voice Handicap Index (VHI-10), fundamental frequency (F0), and vocal aerodynamic parameters (subglottic pressure [SGP]), aerodynamic power [AP], mean expiratory airflow, and maximum phonation time [MPT]), was proceeded before and after VT. Before VT, the mean F0, AP, and SGP of MF patients were significantly higher than Control Group, whereas mean MPT was significantly shorter. After a 4-week VT, the mean F0, AP, and SGP were decreased, and the mean MPT was significantly increased compared with the measurements obtained before VT. After the 4-week VT, the VHI-10 scores in 21 patients reverted to normal Control Group's level (Effective Subgroup), whereas the VHI-10 scores in the other 5 patients remained higher than the normal Control Group (Ineffective Subgroup). Subgroup analysis showed the mean AP and SGP of the Ineffective Subgroup were similar to the Control Group, whereas the Effective Subgroup showed higher AP and SGP. After the 4-week VT, MPT in both the Effective Subgroup and Ineffective Subgroup increased significantly, but AP and SGP in the Ineffective Subgroup did not change significantly. VT is an effective treatment for MF patients with laryngeal hyperfunction. Most MF patients can return to normal voice in 4 weeks. Vocal aerodynamic examination can help in predicting the VT effect and deciding the treatment plan. MF patients without laryngeal hyperfunction may need longer VT period or other adjuvant treatment.