Understanding accented speech: AKA, understanding speech

Kristin Van Engen studies the dynamic back-and-forth between communicators, including the impact that noise and accent have on intelligibility and comprehension.

Kristin Van Engen

Communication among people with different accents is particularly challenging because of the way that our brains expect to hear sounds. People don’t always hear the comfortable sounds they have learned to expect, leading some people to blame the other speaker's ‘strange’ or ‘foreign’ accent. According to Kristin Van Engen, an assistant professor of psychological and brain sciences, this is an understandable but unfortunate attitude that could be counterproductive to successful communication.

Even between people with similar accents, speech comprehension is an incredibly complex task. The acoustic signals people interpret change in a number of respects that are unrelated to meaning. “Your voice is different from the next person's voice. The way you produce a particular sound is different from that person. How your voice sounds depends on the environment, too,” Van Engen explained, “so, we're dealing with a complex and variable signal all the time, even in optimal situations.” People often must interpret never-before-heard acoustic signals from not just strangers, but also friends; yet, remarkably, humans are excellent listeners, deciphering novel speech every day.

Van Engen’s research focuses on understanding this dynamic back-and-forth between communicators. She is particularly interested in the impact noise and accent have on intelligibility (making out words) and comprehension (understanding meaning). In her studies, she asks participants to repeat back sentences they hear word for word. While participants listen to the sentences, their eyes are tracked to measure the diameter of their pupils — a tried-and-true measure of how hard people are listening to the speech, with greater dilation indicating more challenge. Allowing more light into the retina means greater visual input, so people unconsciously dilate their pupils when concentrating on something.

“Everyone has an accent. I have my accent and you have yours, and they might be different, but you don't get to not have an accent."

What Van Engen has found is that even when people can perfectly understand the accented speech, it requires more effort than listening to native speech. According to her research, however, this effort rapidly declines as people get more familiar with the speaker’s accent. “What we see is that the bulk of adaptation happens really quickly, usually in the first couple minutes of exposure,” she said. This finding has major implications for communication between people of different accents: Putting in a little effort, rather than giving up the second one hears a difficult accent, could have huge payoffs for understanding, and it doesn’t even take long. Van Engen also hammered home the idea that conversation is a two-way street. “People speaking a second language want to sound as comprehensible to other speakers as they can. Of course, that's going to mean working on reducing their accent and that sort of thing, but the onus doesn't have to be totally on them; there’s work to be done on both sides,” she emphasized.

Further, looking at individual differences, Van Engen’s research has shown that understanding accented speech is easier for people with larger vocabularies and greater working memory capacity — a measure of how much information you can hold onto in the face of distraction. However, working memory did not influence speech intelligibility with a noise-degraded signal, implying that understanding accented speech is a distinct challenge, separate from a simple inability to hear. Van Engen’s current interpretation is that people make predictions about what sounds are coming next, based on their prior experience with the way words are usually formed. Typically, this is adaptive, easing the load by anticipating the upcoming words, but when accented speech violates expectations it is actually harder to readjust. Put another way, although degraded speech may be a bit tangled, in that it is harder to pick out the relevant signal, accented speech may actually take you down the wrong path. One’s ability to hold onto information in order to “get back on the right path,” which working memory indexes, may be especially important when understanding someone who speaks with an accent.

To be a better listener, Van Engen suggests getting away from noisy environments and putting in that extra effort. Further, she strongly emphasized that people should keep a little perspective; whether an accent is considered foreign or not depends only on who is doing the listening. So, whether you are the one speaking with a ‘foreign’ accent or not, both parties can take practical steps to improve communication. “Everyone has an accent,” Van Engen says. “I have my accent and you have yours, and they might be different, but you don't get to not have an accent."