목적: The objective of this study was to investigate the features of post-thyroidectomy subjective voice disorder by Voice Handicap Index(VHI) and Voice Symptom Scale(VOISS) through aerodynamic analysis and to investigate the appropriate voice therapy intervention. 방법:Eighteen post-thyroidectomy patients who had no recurrent laryngeal nerve paralysis through laryngeal stroboscopy were enrolled for this study. Acoustic and aerodynamic evaluations were performed before operation, 2weeks and 3months after operation. Subjective voice evaluation was performed by VHI and VOISS. Aerodynamic evaluation was analysed by maximum phonation time(MPT), phonation threshold pressure(PTP) etc. Subjective voice evaluation was surveyed through VHI-30 and VOISS. To evaluate patients'symptoms related to functional dysphonia, scores on physical domain in VHI-30 and question number 5, 9, 14, 18, 20, 22, 25, 29, 35, 39 and 40 in VOISS were selected to be compared for each session. 결과:Eight participants scored higher on 2 weeks and 3 months after operation compared to pre-operation, in VHI and VOISS. The 8 participants had no significant difference with pre-operation in acoustic evaluation, but all showed reduced MPT and 5 of them showed reduced MPT and increased PTP value at a time. Laryngeal massage and breathing training were simultaneously treated to those 8 participants, resulting in improvement in MPT and PTP in everyone compared to pre-treatment. 결론:Patients who complained voice change after thyroidectomy were all shown to have reduced MPT and increased PTP in some by aerodynamic evaluations. Reduced MPT may imply some problem in air flow beneath glottis. Increased PTP suggests more effort in vocalization mechanism than pre-operation. Comparing aerodynamic evaluations may provide information on behavioral interventions. Additionally, study on laryngeal massage and breathing training simultaneously treated to patients with such dysphona is needed to be conducted with larger number of participants.