Brain recordings show that background noise strongly impairs children’s ability to concentrate on a single speaker
Neuroscientists of Aalto University in Finland and Erasme Hospital in Belgium compared adults' and children's brain activities during the so-called ‘cocktail party effect,’ that is the ability to pay attention to a single speaker in a noisy environment. Compared with adults, the children's brain activity followed less reliably the speaker's voice, especially when the background noise was high.
“Childrens’ ability to concentrate on their teacher is disrupted in a noisy environment, such as in a noisy class room, and this may affect their learning,” says Aalto University senior researcher Veikko Jousmäki.
Published in the Journal of Neuroscience, the study compared adults with children that were 6–9 years of age. The researchers used magnetoencephalography (MEG) to follow the brain activity while the subjects were asked to focus on one speaker’s voice among the background noise. The background noise consisted of the other speakers’ stories, and the noise level was modified in different sessions.
Childrens’ ability to concentrate on their teacher is disrupted in a noisy environment and this may affect their learning.
The colourful brain regions are driven by the listened speech stream. There is a significant difference between adults and children.
Without any background noise, the brain accurately tracked the speech stream in both adults and children. When the level of background noise was increased, adults' brains were still able to follow the intended speaker, but children lost this focus rather quickly.
The results imply that the ability to concentrate in a noisy environment develops with age. Schoolchildren are not yet able to easily pick up the intended speech stream among the background noise. The brain recordings agree with previous findings showing that children have difficulties in understanding speech in noisy surroundings.
“Brain recordings allowed us to see how the listener’s auditory cortex was driven by the listened speech stream. When the level of background noise increased, adults’ brains still continued to track the intended speaker’s voice as a coherent stream, whereas children easily lost this focus,” says Jousmäki.
This study is a part of a larger series of experiments that were started by developing a coherence-based method to follow the relationship between brain signals and the listened natural speech. The same Finnish–Belgian research team demonstrated already in 2013 how the right-hemisphere auditory cortex reacts to different rhythms of speech. More recently, this analysis method has been applied to the study of people suffering from autism-spectrum disorders.
“Our next goal is to find out how children could be helped to cope with the often noisy growth and learning environments,” says Jousmäki.
Article: Cortical tracking of speech-in-noise develops from childhood to adulthood, https://doi.org/10.1523/JNEUROSCI.1732-18.2019
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