Profile: Kaori Idemaru

Kaori Idemaru

PROFESSOR, JAPANESE LINGUISTICS

BY MATT COOPER, OREGON QUARTERLY PHOTO BY DUSTIN WHITAKER, UNIVERSITY COMMUNICATIONS

Kaori Idemaru was a middle schooler living in the Japanese countryside when she discovered that learning a foreign language—English, in her case—could open a portal to a new world.

Today, Idemaru studies how speech is learned and perceived. Her findings contribute to a range of linguistic fields, including language acquisition and processing, cognitive functioning, cultural understanding, and identity—that is, how language reflects one’s class, region, and even gender.

In a novel project with Professor Lori Holt of Carnegie Mellon University, Idemaru tested listeners’ recognition of the words “beer,” “pier,” “deer,” and “tear” when hearing an artificial accent. The researchers found that the human brain, in recognizing closely related words, picks and chooses from various acoustic properties such as pitch and the pronunciation of consonants; it effectively acts like an equalizer, giving more (or less) weight to whichever property will aid recognition.

The researchers deemed this cognitive flexibility “dimensionbased statistical learning”: the brain sifts through different acoustic properties to recognize a word despite fluctuations caused by accent and other factors. Idemaru is expanding on this research with University of Oregon colleagues Charlotte Vaughn and Volya Kapatsinski.

“When we perceive speech sounds, we’re actually using multiple acoustic properties,” Idemaru says. “But the weight we give to those properties isn’t fixed; some people don’t use pitch to perceive words, and some people overuse pitch, but we get accustomed to how speakers vary in those acoustic dimensions. We have really fine-grained perceptual strategies to understand the language we’re hearing.”