A study finds that South Korea's first Olympic champion in figure skating Kim Yu-na was calm and composed when she broke world records at the Vancouver Winter Olympics.

Professor Cho Dong-wook from Chungbuk Provincial University, a voice analysis expert, said Tuesday that the vibration frequencies of Kim's vocal cords were 283.73 hertz and 288.61 hertz when she spoke after breaking world records with her short program and free skating events.

The figures are above her usual frequencies of about 250 hertz.

However, the stability level was about 40 percent in both cases, higher than her usual 36 percent.

Cho said that Kim is very confident and bold compared to ordinary people, who tend to speak faster when they are overjoyed.