麻豆淫院

"In a sense, you listen to every person with different ears, because everyone speaks differently," says Orhun Ulu艧ahin, who will defend his dissertation at Radboud University on October 17. His research shows that our brains adapt rapidly to a speaker in order to understand them, and that we even adapt our own speech to the person we are talking to.

No two people sound the same. Whether a five-year-old girl says "bottle" or an eighty-year-old man says it is a world of difference. In everyday life, we as listeners have to deal with those differences. Therefore, our brains make adjustments that are specific to individual talkers. Thus, whether someone speaks fast or slow, with a high or low pitch, or with a particular dialect or a foreign accent, we quickly adjust in order to understand them.

This mechanism not only affects the way we listen, but also the way we speak, Ulu艧ahin found. "What you know about the way someone talks influences how you talk yourself," according to the brain researcher. "During a conversation, people adjust their voices slightly, making them sound more like their conversation partner acoustically."

Higher or lower pitch

In various experiments, Ulu艧ahin had test subjects listen to recorded voices and repeat them. In one of the tests, people were asked to repeat a sentence at the same pace as the recorded voice. But the researchers analyzed not only how synchronously people spoke, but also at what pitch. People who heard the sentence in a higher pitch also spoke higher themselves, and vice versa for a lower pitch.

It was striking that this effect was smaller when the test subjects had been listening to a particular voice for a longer period of time. For example, they listened to a relatively high-pitched female voice for twenty minutes. Then they were given a test in which they had to repeat a sentence spoken by the same female voice, but at a lower pitch. In that case, people were less inclined to adjust their own voice to a lower pitch, suggesting that they then used information they already had about a speaker.

This result shows that our listening and speaking systems use the same resources in the brain. "What you know about the way someone talks not only influences how you listen, but also how you talk yourself," according to the brain researcher.

"The language network in our brain is even larger and more dynamic than we thought. Almost our entire left brain hemisphere is involved in language, but we cannot pinpoint exactly where we form words or plan lip movements beyond broad areas. This research shows that, at a process level, listening and speaking are not entirely different things either, but are closely interconnected."

Recognizing words

In another experiment, Ulu艧ahin had people repeat a word. The word they heard was acoustically modified very subtly, so that, for example, the word "beterschap" ("get well" in Dutch) became something more like "beuhterschap." In this case, people did not adjust their own voices.

"You just hear 'beterschap," even though it actually sounds slightly different," the researcher explains. "Your brain goes for the most likely option, the one it already knows. That's why you pronounce the word the same way you would otherwise. So, there are clear limits to these adaptive processes as well."

Ulu艧ahin is working as a postdoctoral researcher at the Donders Institute, where he is developing a computational model that mimics human word recognition by picking out words from a sentence and adapting to different speakers.

"For one voice, the model has to interpret a sound as a 'b' while it may have to interpret the exact same sound as a 'p' for someone else because these two people pronounce these sounds differently," he says.

"We want the model to make mistakes just like humans do, rather than to develop a model which makes the smallest number of mistakes like a tech company might want to do. That's the challenge. Hopefully, this will help us understand our brains even better."