Scientists develop brainwave-based test for speech comprehension

March 8, 2018, KU Leuven

Researchers have developed a test for more accurate diagnosis of patients who cannot actively participate in a speech understanding test. Such patients include very young children or people in comas. In the longer term, the method also holds potential for the development of smart hearing devices.The new technique was developed by Professor Tom Francart and his colleagues from the Department of Neurosciences at KU Leuven, Belgium, in collaboration with the University of Maryland.

A common complaint from people with is that they can hear speech but they can't determine its meaning. Being able to hear speech and actually understanding what's being said are two different things.

There are well-established tests to determine a patient's ability to hear soft sounds. Audiologists can test with a series of tones over headphones. An alternative option makes use of EEG, which is often used to test newborns, in which click sounds are presented through small caps over the ears. Cranial electrodes measure brainwaves in response to these sounds. The great advantage of EEG is that it is objective and allows for passive testing. "This means that the test works regardless of the listener's state of mind," says co-author Jonathan Simon from the University of Maryland. "We don't want a test that would fail just because someone stopped paying attention."

But to test speech understanding, the options are much more limited, explains lead author Tom Francart from KU Leuven: "Today, there's only one way to test speech understanding. First, you hear a word or . You then have to repeat it so that the audiologist can check whether you have understood it. This obviously requires the patient's active cooperation."

Therefore, scientists set out to find an EEG-based method that can measure hearing as well as speech understanding.

"And we've succeeded," says Tom Francart. "Our technique uses 64 electrodes to measure someone's brainwaves while they listen to a sentence. We combine all these measurements and filter out the irrelevant information. If you move your arm, for instance, that creates brainwaves, as well. So we filter out the brainwaves that aren't linked to the sound as much as possible. We compare the remaining signal with the original sentence. That doesn't just tell us whether you've heard something, but also whether you have understood it."

The scientists compare the brain wave sequence to the soundwave of the sample sentence. Sufficient similarity indicates that the patient understood the sentence. This makes it possible to objectively and automatically determine whether someone understands what's being said. This is particularly useful in the case of patients who cannot respond, including in a coma.

The findings can also contribute to smart hearing aids and cochlear implants, Francart says. "Existing devices only ensure that you can hear sounds. But with built-in recording electrodes, the device would be able to measure how well you have understood the message and whether it needs to adjust its settings—depending on the amount of background noise, for instance."

Explore further: Research finds brain responses to lip-reading can benefit cochlear implant users

More information: Jonas Vanthornhout et al, Speech Intelligibility Predicted from Neural Entrainment of the Speech Envelope, Journal of the Association for Research in Otolaryngology (2018). DOI: 10.1007/s10162-018-0654-z

Related Stories

Research finds brain responses to lip-reading can benefit cochlear implant users

August 15, 2017
A world-first study has found that lip-reading may have a beneficial effect on the brain and on a person's ability to hear with a cochlear implant, contrary to what was previously believed.

Modern life is damaging our ears – probably more than we realise

April 10, 2017
Noise exposure is the main cause of preventable hearing loss worldwide. It now accounts for more than a third of all cases of hearing loss in developed countries – and city dwellers are most at risk. A study published recently ...

People who hear voices can detect hidden speech in unusual sounds

August 21, 2017
People who hear voices that other people can't hear may use unusual skills when their brains process new sounds, according to research led by Durham University and University College London (UCL).

New program improves hearing aid use for older adults

March 20, 2017
More than half of older adults have some form of hearing loss, impacting everyday life and significantly affecting their health and safety if left untreated. Hearing aids are the most common treatment for hearing loss; however, ...

Pop-outs: How the brain extracts meaning from noise

December 20, 2016
When you're suddenly able to understand someone despite their thick accent, or finally make out the lyrics of a song, your brain appears to be re-tuning to recognize speech that was previously incomprehensible.

Recommended for you

Cell study reveals how head injuries lead to serious brain diseases

November 16, 2018
UCLA biologists have discovered how head injuries adversely affect individual cells and genes that can lead to serious brain disorders. The life scientists provide the first cell "atlas" of the hippocampus—the part of the ...

Newborn babies' brain responses to being touched on the face measured for the first time

November 16, 2018
A newborn baby's brain responds to being touched on the face, according to new research co-led by UCL.

Precision neuroengineering enables reproduction of complex brain-like functions in vitro

November 14, 2018
One of the most important and surprising traits of the brain is its ability to dynamically reconfigure the connections to process and respond properly to stimuli. Researchers from Tohoku University (Sendai, Japan) and the ...

New brain imaging research shows that when we expect something to hurt it does, even if the stimulus isn't so painful

November 14, 2018
Expect a shot to hurt and it probably will, even if the needle poke isn't really so painful. Brace for a second shot and you'll likely flinch again, even though—second time around—you should know better.

A 15-minute scan could help diagnose brain damage in newborns

November 14, 2018
A 15-minute scan could help diagnose brain damage in babies up to two years earlier than current methods.

New clues to the origin and progression of multiple sclerosis

November 13, 2018
Mapping of a certain group of cells, known as oligodendrocytes, in the central nervous system of a mouse model of multiple sclerosis (MS), shows that they might have a significant role in the development of the disease. The ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.