Brain stem role in speech perception reassessed

The brain stem plays a greater role in speech perception than previously thought, according to Jackson T. Gandour, a professor of speech, language, and hearing sciences at Purdue University.

“We have found that early activity in the brain stem is shaped by a person’s language experience, even while the person is asleep,” Gandour said. The brain stem is the lower part of the brain, located near the cochlea and the auditory nerve, which is where pitch-processing begins.

Gandour also noted that brain stems are tuned differently depending on the sounds of a person’s mother tongue.

Collaborating with Purdue auditory electrophysiologist Ananthanarayan Ravi Krishnan, Gandour compared electrical activity in young adult speakers of Mandarin with those of speakers of English.

“Never did I expect we would find that language experience would shape the way the brain stem works,” Gandour said. “The idea is that this sensory signal undergoes a set of transformations that are far more
complicated than we originally thought.”