Related Help Pages: Hearing loss Hearing aids

Have you heard of the McGurk effect?

The McGurk effect was first realized, discussed and named in 1976. It's an effect that shows the importance of speech in how we interpret sound, especially very nuanced sounds. The McGurk effect can be demonstrated in a lab when a spoken sound is played for someone and at the same time they are presented with a video of lips moving that form another sound. The end result is that person interprets that he or she heard the sound that the mouth was making - visual cues override what the person has actually heard.

McGurk effect explanation

For example, take two very similar syllables - "ba" and "va." If a person in the lab hears a recorded voice saying "ba," but sees a video of a voice saying "va," that person will report that he or she has heard the word va, even though that is untrue. However, if the person is recorded mouthing the syllable "tha," this will be too obvious a mismatch and the person will report correctly that he or she has heard "ba."

The McGurk effect reveals that speech reading is effective for those with hearing loss because visual cues are very important. For those with minor hearing loss, speech reading can be a very valuable way to maximize the hearing they still do have. Also, this reveals more about why watching the mouth is so important in intense language learning.

However, until now, the mechanisms of the McGurk effect were unknown. But bioengineers from the University of Utah, in a study published in PLOS ONE in September 2013, discovered the mechanisms in the brain that allow for the McGurk effect, as lead author Elliot Smith explains:

"For the first time, we were able to link the auditory signal in the brain to what a person said they heard when what they actually heard was something different. We found vision is influencing the hearing part of the brain to change your perception of reality – and you can't turn off the illusion," Smith said. "People think there is this tight coupling between physical phenomena in the world around us and what we experience subjectively, and that is not the case."

These findings might also reveal why it's often difficult for older adults with hearing loss, who often have vision problems as well, to hear better with well-fitted, high-quality hearing aids and other listening devices. The researchers suggest that assistive listening devices and speech-recognition software might also benefit from a camera, in addition to a microphone, to enhance users' hearing experience.

According to bioengineer Bradley Greger, our brains are doing something interesting:

"We've shown neural signals in the brain that should be driven by sound are being overridden by visual cues that say, 'Hear this!'" he said. "Your brain is essentially ignoring the physics of sound in the ear and following what's happening through your vision."

This study might also have implications for other research on what drives language processing and what happens when it goes wrong, such as with dyslexia.

Take our online Hearing Check

Featured professionals near you

Leesburg Family Hearing
211 Gibson St NW Ste 202
Leesburg, VA 20176

View Details

Blue Ridge Speech & Hearing Center
19465 Deerfield Ave Ste 201
Leesburg, VA 20176

View Details

Reston Ear Nose and Throat
1860 Town Center Dr Ste 335
Reston, VA 20190

View Details

Professional Hearing Aid Service
1800 Town Center Dr Ste 315
Reston, VA 20190

View Details

Search for a professional

The Healthy Hearing Report

The Opn sound paradigm is expanding
Need help?

Need help?

We have more hearing clinic reviews than any other site!

Find a trusted clinic near you: