Scientists find how brain recognizes speech sounds
New research from the University of California San Francisco (UCSF) has found that the brain processes speech by following “an acoustic trail” formed by the way our mouths shape sounds.
Using neural recording devices, scientists studied the brain processes in six patients undergoing surgery for epilepsy. The patients listened to 500 unique sentences spoken in English by 400 different people. Researchers found that the brain responded to “features,” which they defined as “’acoustic signatures’ that the human body makes when we move our lips, tongue or vocal cords.” Examples of features include “plosives”—made when speaking words starting with the consonants p, t, k, b and d—and “fricatives”—made with the sounds of s, z and v.
The study’s findings, published in the journal Science, showed that the human brain recognizes “shapes” of sounds in a way similar to how it recognizes visual objects. By gaining a deeper understanding of how the brain processes speech, researchers said they hope to contribute to research being done involving speech and reading disorders.