How did Kim Yu-na`s voice and delivery help Olympic bid?

Olympic figure skating champion Kim Yu-na has played a critical role in South Korea`s successful bid to host the 2018 Winter Olympics.

She won over International Olympics Committee members in her presentation in Durban, South Africa, Wednesday with an appealing voice and correct pronunciation.

Cho Dong-uk, a professor at the Biological Signal Analysis Center of Chungbuk Provincial College, analyzed Kim’s voice in the presentation, which is said to have been as perfect as her skating ability.

Based on his analysis, the scholar said her voice was comparable to those of announcers.

Cho divided Kim’s 170-second presentation into two sections and analyzed the second 100-second section with a voice analyzer. Her pitch, or vibration of vocal cords per second, was 238 hertz in the first part and grew to 257 hertz in the latter part.

"As Kim naturally reflected changes in her emotions in her voice, her pitch changed,” Cho said.

The share of unvoiced sounds, a yardstick for pronunciation stability, was 32 percent on average. “Kim’s proportion of unvoiced sounds was similar to the announcers’ average ratio of 30-35 percent,” Cho said.

Kim also showed high scores in two measurements that reflect accuracy in pronunciation: the jitter, a variation of vocal cords, and the shimmer, an amplitude of vibration. The former was 2.1 percent, lower than the average of 2.6 to 3.0 percent in ordinary people, and the latter was 1 decibel, lower than 1.5 decibels for ordinary people.

Cho said, “Kim maximized her appeal and likability with the appropriate mix of emotion, high voice stability and correct pronunciation,” adding, “This combined 30 percent talent and 70 percent effort.”

The professor also analyzed the voice of Teresa Rah, spokeswoman of the Pyeongchang bidding committee. “The pitch of Rah’s voice hardly changed (237 to 238 hertz) and stability was 35 percent,” adding, “Notably, her shimmer was excellent at 0.9 decibels, lower than the average 1.0 to 1.2 decibels for announcers.”

“Rah is a hard-headed expert who isn’t swayed by emotions and has a captivating voice.”

Cho is a bio-signal analyzer who uses biological signals such as voice and facial expression to analyze diseases, personalities and emotions of people. He is known for bio-signal analyses of famous figures such as North Korean leader Kim Jong Il, South Korean singer Cho Yong-pil, and the late South Korean president Roh Moo-hyun.

straw825@donga.com