In order to minimize the complication rates and voice disturbances during thyroidectomy, intraoperative nerve monitoring(IONM) is a widely used intervention. In this study investigators will compare conventional surgery with IONM used surgery. Randomly chosen half of the patients will be operated with IONM. Vagus, recurrent and superior laryngeal nerves will be monitored during surgery and measured for nerve integrity . Rest of the patients will be operated with standard conventional method. All participants will be analyzed with a computer program for their voice quality preoperatively and postoperatively at 14th day of surgery.