Keizer, whose book could be read as a call to arms for quieting our far too noisy world, would surely be gratified to learn that science is finally understanding the impact that noise has on what he calls "the weakest of us" — "a set of members whose only common features are their humanity and their lack of clout. [This] list will include children (some of whom, according to the World Health Organization, receive more noise at school than workers from an eight-hour work day at a factory)."
Indeed, in a paper just posted to the website of the journal Child Development, researchers from the University of Wisconsin-Madison report finding that the presence of background noise in the home or at school makes it more difficult for toddlers to learn new words.
Prior research on the impact of environmental noise on children has suggested that too much of it can affect children both cognitively and psycho-physiologically, which manifests itself as increased levels of the stress hormone cortisol and a faster heart rate as well as poorer school performance.
The new research, however, focused specifically on word learning in the noisy environments children may inhabit at home and school.
Across three studies that involved children ranging from ages 22 months to 30 months, toddlers were taught names for unfamiliar objects while being exposed to either louder or quieter background speech. They were then tested on their ability to recall the words and recognize the objects when they were labeled.
In all the studies, louder background speech hindered the toddlers' ability to learn.
"Hearing new words in fluent speech without a lot of background noise before trying to learn what objects the new words corresponded to may help very young children master new vocabulary," suggested study co-author Jenny Saffran, a professor at the University of Wisconsin-Madison, in a press release.
The good news is that the researchers found that in the noisier environment, intentionally drawing the toddlers' attention to the specific sounds of the new words helped compensate for the noisy environment.
Sadly, such an advanced teaching technique is not one likely to be natural to the parents and families of low-income children who are already at high risk of not interacting enough with their children. This lack of caregivers talking directly with infants is what researchers believe leads to the famous 30-million-word gap between what low-income and more affluent kids have heard by age 3.
So maybe the word gap emerges not just from a lack of talking to a baby, but because when it does occur, it happens in the noisy, chaotic environments that are the hallmarks of families living in poverty.
Not that this new research of the toll noise takes on developing brains is limited to those who live in overcrowded or chaotic homes. Today's toys are noise machines — visit a daycare center and you'll learn that the squealing of children over beeping, singing and chirping toys makes for an ear-splitting setting.
Middle-class homes are not immune. The American Academy of Pediatrics (AAP) estimates that kids spend an average of seven hours a day on televisions, computers, phones and other electronic devices — not including when their sounds are the background of daily life.
The AAP says "Children and teens should engage with entertainment media for no more than one or two hours per day, and that should be high-quality content. ... Television and other entertainment media should be avoided for infants and children under age 2. A child's brain develops rapidly during these first years, and young children learn best by interacting with people, not screens."
Noise truly is a great plight of our time. Enjoying quiet should be a top priority for everyone — and be considered a right for children.