I recently posted two very long posts, on the influence of acoustics and greenery on learning, respectively, which once were slated to be part of a book that I just couldn’t scrounge the time together to complete. One of the chapters-to-be was on the importance of air quality in learning — and damn, how timely it would have been if I could have pulled that all together pre-COVID-19?!
Oh well. Instead, in the attempt to exorcise the never-to-be-completed book, as well as to close the chapter on this blog and move into more thinking and writing on language and literacy, I posted those two chapters and have been in the process of moving on.
While I most likely won’t ever write that book, I’d still like to highlight the critical importance of air quality in schools and learning, which has become all the more apparent during a time of a respiratory virus, but which is important at all times. And since I don’t have the time to write it all up in full, I’ll post links to the threads that I had laying about in a document instead, and let you, dear reader, complete the thoughts:
He found that the variation in average results were staggeringly different. The most polluted days correlated with the worst test scores. On days where the air quality was cleanest, students performed better.
To determine the long-term effects, Roth followed up to see what impact this had eight to 10 years later. Those who performed worst on the most polluted days were more likely to end up in a lower-ranked university and were also earning less, because the exam in question was so important for future education.
“How air pollution is doing more than killing us” by Melissa Hogenboom in BBC Future
When the level of fresh air in the classrooms was increased, the students performed up to seven per cent better than when they were working on the tests in their usual indoor climates. The study also revealed that the students did not themselves notice that they were not quite as astute in the poorer climate.
“Bad air quality makes children perform worse in schools” by Jonas Salomonsen in ScienceNordic
A long and really important investigation on the health impacts of air pollution on schools situated near busy roads by The Center for Public Integrity that has not gotten the attention it deserves. Read the entire thing. Read it again. And then reflect on the following:
Southern California’s air agency, the South Coast Air Quality Management District, earmarked settlements from polluting companies and other funds to cover the cost of such filtration at about 80 schools near freeways or other pollution sources. Nothing’s preventing other states from following the same model.
“The technology is well established, the installation is straightforward and the maintenance is simple,” said district spokesman Sam Atwood, who doesn’t recall officials from other states getting in touch to learn from his agency’s experience.
“The Invisible Hazard Afflicting Thousands of Schools” by Jamie Smith Hopkins for The Center for Public Integrity
If you’re interested in the idea of how the physical environment can affect people, I recommend giving this TED Radio Hour episode, “The Power of Spaces,” a listen. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
I found David Byrne’s discussion of how acoustic spaces can affect creativity especially interesting, given our exploration here of how acoustics can affect learning.
With a classroom having good acoustical characteristics, learning is easier, deeper, more sustained, and less fatiguing.
—The Acoustical Society of America, in its introduction to Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 1: Permanent Schools
When I first moved to NYC from California, I was taken aback by the unceasing din. In our first apartment, my wife and I were treated to an all-night alleyway party each weekend by our downstairs neighbors. In desperation, we bought a white noise machine, but this proved to be a mostly futile gesture.
Our second apartment was perched above a popular nightspot, which considerately recycled its beer bottles outside our bedroom window at three AM every morning. We got an additional white noise machine and put up layers of cardboard against the windows. But outside of professional acoustical treatment, there’s no hiding the intense, high decibel sound of twenty-five gallons of beer sodden glass bottles slamming repeatedly into their brethren as they are dumped into a bin.
So I well know how noise can impact a person’s well-being. But maybe I’m just overly sensitive. I see people everyday move along unphased as truck horns blast in their face. Humans are a highly adaptive species, after all, and we go on about our business with a cacophony of ambient noise hovering about us like smog.
While many of us may consider noise to be a minor nuisance (except, perhaps, when we are trying to sleep), it can have a profound impact on our health. Studies have shown that constant exposure to noise, such as living near a highway or airport, can lead not only to loss of sleep, but hypertension, higher blood pressure, Type 2 diabetes, heart problems, and lower birth weight, just to name a few long-term consequences (Casey, James, & Morello-Frosch, 2017).
There’s a lot more we could say about the impact of sound on health, whether physical or psychological. But most pertinent to our focus are the findings on how harmful noise can be for learning, most especially in the places where learning should be what is held most sacred: our schools.
Given that children are far more vulnerable to noise than adults (Klatte, Lachmann, & Meis, 2010), ensuring that children have a learning environment unthreatened by noise should be a commonsense goal. Yet how frequently have you heard an education reformer discuss acoustical treatment as a school or district improvement initiative? […silence… crickets… beeping horns…]
Never? Exactly. So let’s start talking about it. In this post, we’ll examine the impact of noise on students and on teachers, then consider what we can do about it.
The Impact of Noise on Student Learning
Chronic Noise: What You Hear Is How You Learn
The natural sensitivity that the human ear has to auditory vibration is not a primary design consideration for most schools. Surfaces are hard. Corners are sharp. Floors are tiled. Every squeak of a sneaker, shout of a hormonally charged teen, recurring bell at the end of a period, each slam of a heavy door can be amplified, reverberating throughout the building and, especially during fire drills, deep into the marrow of one’s bones.
In 1975, a seminal study by Arline Bronzaft and Dennis McCarthy at a school in NYC illuminated the impact of noise on learning. At Public School 98 in uptown Manhattan, the elevated 1 train roared by a mere two hundred feet from the southeast side of the building every few minutes, disrupting learning in nearby classrooms.
One can imagine a teacher hovering exasperated in mid-sentence for the 6th time that period, awaiting the rumbling clatter of the train to recede into the distance, her students’ flighty attention ebbing away just as rapidly.
Four year’s worth of data show that students located in classrooms nearest the train had far lower reading scores than those on the quieter side, lagging behind by three months to as much as a year.
Imagine if your child were placed in a classroom where they might lose anentire year’s worth of reading ability simply due to where the classroom happened to be located in the building.
To their credit, these results were significant enough to spur the NYC Board of Education and MTA into immediate action (a verb phrase not commonly associated with either entity). The school installed special tiling in the classrooms facing the train, and the Metropolitan Transit Authority insulated the tracks adjacent to the school. In a follow-up study, students across all classrooms were found to have comparable reading levels as a result of these simple interventions (Bronzaft, 1981). This demonstrates that the delay in student reading ability was not due to the quality of the staff nor curriculum, but solely to the location of the classrooms in the building.
Later studies have further revealed the impact of noise and school acoustics. Chronic exposure to noise, such as residing near a highway or airport, impairs a child’s ability to learn. In 1973, researchers measured the reading and auditory processing abilities of children living on different floors of the Bridge Apartments, a quartet of 32 story high rises bestride one of the busiest highways in uptown Manhattan (Cohen, Glass, & Singer). They found that children living on lower floors, in greater proximity to the unrelenting noise of the highway, had lower reading scores compared to those on higher floors. The longer a child lived on a lower floor, the greater the gap.
This is a vivid visualization of how where a child lives can either expand or inhibit their opportunities to learn—down to the floor they may happen to live on within the very same building. Noise pollution, as with pollution of other sorts, is worse in neighborhoods segregated by race or class (Casey et al., 2017). Schools serving primarily poor, Black, or Latinx communities thus tend to have greater amounts of ambient noise, which most likely means their classrooms will also be noisier—unless those spaces are constructed with materials that absorb external noise, or are belatedly given acoustical treatment (we’ll look more at how to fight noise in a minute).
In a series of studies of schools located near airports in New York, Munich, the Netherlands, Spain, and the UK, cognitive tasks requiring memory and language processing, such as learning a word list, were impaired by aircraft noise, as were reading comprehension scores and auditory tests of speech perception (Evan & Maxwell, 1997; Hygge, Evans, & Bullinger, 2000; Stansfeld et al., 2005).
In sum, noise makes it harder for all children to hear, to read, and to remember.
Now is probably a good time to highlight the strong connection between reading comprehension and auditory learning. While our visual system is clearly an important component of reading, comprehension of the written word is founded on the ability to discern the sounds that letters and words are composed of. For children that struggle with reading, especially those classified as dyslexic, their difficulty is closely related to trouble with auditory processing (Hornickel & Kraus, 2013).
All children should learn in environments in which speech can be clearly heard, but it is especially critical for young children, children with hearing impairments, learning challenges, or learners of a new language (Kristiansen et al., 2011).
The Importance of the Intelligibility of Speech
The connection between noise and learning makes a lot of sense when you consider that speech and language are central to most classroom instruction. The more difficult it is to discern individual words, the more cognitive energy a brain must exert to fill in the gaps, drawing from prior knowledge and context (Pichora-Fuller, 2007). This is similar to the challenge a struggling reader faces when they expend more cognitive energy decoding words rather than deciphering meaning. And while you may be able to hold a conversation in the middle of a dance club and understand what your inebriated friend is saying, don’t expect that children can so easily fill in the blanks. Even those adults who are deaf—and are therefore experienced lip readers—do not recognize a large majority of words spoken to them without signing (Altieri, Pisoni, & Townsend, 2011).
A 2000 report, “Classroom Acoustics: A Resource for Creating Environments with Desirable Listening Conditions,” framed the difficulty children face in understanding classroom speech thus:
In many classrooms in the United States, the speech intelligibility rating is 75 percent or less. That means that, in speech intelligibility tests, listeners with normal hearing can understand only 75 percent of the words read from a list. Imagine reading a textbook with every fourth word missing, and being expected to understand the material and be tested on it. Sounds ridiculous? Well, that is exactly the situation facing students every day in schools all across the country. (Seep et al., 2000)
Let me repeat that claim above again in a different way to stress this point: in many classrooms, due to poor acoustics, children may not understand 25% or more of the words their teacher speaks. It’s hard to verify a statistic like that, but there have been some surveys of acoustics across many schools in the world, and what is clear is that the acoustical quality of schools and classrooms can vary quite dramatically (Mealings, 2016).
Given that the majority of learning in most classrooms is based upon speech, you might conclude that acoustics would be one of the primary concerns of classroom design. You may also think that it would be one of the first things a school leader considers when evaluating the learning conditions of their classrooms. The reality is that acoustical design is rarely considered due to cost and complexity, and noise continues to be dismissed as a minor nuisance. Meanwhile, children are sitting in classrooms where they miss a substantial portion of what their teacher says each day, due to no fault nor inattention of their own.
Noise Begets Noise
But it is not only chronic, deafening noise from cars, airplanes, and trains that can impair learning. The background noise within a classroom can also be harmful. In a 2006 study, 158 eight-year-olds were randomly assigned to classrooms with three different noise conditions and administered tests: normal sound levels during testing (no talking), a constant stream of children babbling (around 65 decibels), and classroom babble with intermittent external noise events, like sirens (Dockrell & Shield). One of their findings was that classroom chatter can have a detrimental effect on student performance on both verbal and nonverbal tasks. Which should surprise exactly no one who has ever tried to concentrate while others around them were gabbing.
In a survey of secondary schools in London, researchers measured the unoccupied levels of ambient noise and reverberation in classrooms and compared it against sound levels during lessons across multiple subjects and activities (Shield et al., 2015). They found that sound levels during instruction were related to the acoustical quality of the rooms themselves, and that disruptions to learning, such as students talking or shouting, were correlated to rooms of poorer acoustical quality. Thus, the poorer the acoustical quality of room—as measured before anyone occupies it—the noisier the room is likely to be once kids are in there. And the more likely, as a result, learning will be thrown off track.
This gives us a general principle: when a space is of poor acoustical quality, it is more likely to become noisier once in use. In other words, noise begets noise. And noise tends to lead to less self-regulated behavior. In a bar or a club, maybe that’s a desirable thing. But not in a school.
We can see this everyday in school cafeterias. Cafeterias can be some of the worst acoustical offenders, becoming deafeningly loud, which is hardly surprising given they are chock full of hungry students with pent up energy socializing in giant rectangular spaces rife with reflective surfaces. Rather than a respite after a long morning of thinking and learning, lunch breaks instead become a time of sensory overload due to poor acoustics. If it’s an option, students sensitive to noise seek to escape to the calm, restorative environment of the classroom of their favorite teacher instead.
All teachers dread the class that must be taught after lunch. That’s the period when kids come in buzzing with the latest scuttlebutt. In my first years of teaching in a self-contained 5th grade classroom, I learned that transitioning my students into academic learning too swiftly after lunch would result in no academic learning. It was as if they needed a break from their lunch break. Looking back, I wonder how much the frayed nerves of my students can be attributed to a lunch period spent in a noisy basement with terrible acoustics?
Because noise doesn’t only hinder learning. It also causes fatigue. Earlier, we discussed how when it is harder to hear, our brains must work harder to fill in the blanks. This can not only be taxing, but furthermore cause us to miss subtle cues and thus have distorted perceptions in social situations (Anderson, 2001). When you consider the trouble that adolescents already have with self-image and complex social situations, now consider the fisheye effect of cafeteria noise. It’s a disaster waiting to happen.
Another overlooked area of poor acoustics are school stairwells. Again, these tend to be filled with hard, reverberant surfaces that echo with the scuffle of sneakers and shouts. Some stairwells, like the one at a Bronx middle school in the picture below, carry sound across multiple floors. As groups of students traverse the stairs, noise magnifies. Students grow louder as they enter the stairwell in an effort to be heard, demonstrating the power of the signal-to-noise ratio in real-time.
Signal-to-noise ratio is the audibility of what you want to hear (such as someone’s voice) against background noise. In order for speech to be intelligible, a positive signal-to-noise ratio must be maintained, which is why we tend to raise our voices when there is more noise around us.
The Impact of Noise on Teachers
Unwittingly, teachers themselves may exacerbate the noise in their classrooms. It is natural to speak more loudly when there is noise around us. Given the prevalence of reverberating sounds in classrooms, compounded by frequent group work and the natural propensity of children to speak loudly and excitedly, teachers invariably end up talking at higher volumes in the battle to make themselves heard. Some teachers operate nearest to a level of hoarse hollering as a matter of normalcy. They may proudly term this their “teacher voice.”
But speaking constantly at higher volumes has consequences: teachers are more susceptible to voice-related issues. Across two studies, one in Sweden and one in the U.S., teachers were “the commonest ‘at risk’ occupation” and “four times more commonly represented clinically than in the population at large” (Williams, 2003). Another study found that poor acoustics and related voice problems reduced teacher well-being, as well as increased absences due to illness (Kristiansen et al., 2011). Teacher voice problems also may have an impact on the economy: one study estimated a cost of $2.5 billion per year to the U.S. economy due to effects such as absences, clinical visits, and medication (Verdolini & Ramig, 2001), while another study of Colombian teachers estimated the cost as potentially up to 37% of a teacher’s monthly wage (Cantor Cutiva & Burdorf, 2015). Even more importantly, a teacher’s vocal impairment can make it difficult for students to understand what a teacher is saying (Rogerson & Dodd, 2005).
Another way of saying all of this is that while it may be obvious that loud, constant, chronic noise hinders learning, the poor acoustical quality of schools and classrooms can also have a cumulatively detrimental impact, both for teachers and for students.
This doesn’t mean that classrooms and schools should all be expected to be hushed rectories where you can hear a pin drop. A certain degree of ambient sound may even support focus, at least for tasks involving creativity (Mehta, Zhu, & Cheema, 2012). I find that I can sometimes be more focused and productive when writing, for example, when I am somewhere with an ambient buzz of social activity and conversation, like at a cafe.
But it does mean that too much noise, whether chronic or acute, external or internal, will make learning significantly more difficult for the students who can least afford to fall behind.
Add to all of this the unceasing calls over a loudspeaker that can interrupt instruction throughout a school day. Well-organized schools ensure such calls are only made when absolutely necessary. At some schools, however, unscheduled announcements cause needless additional noise and constantly impede classroom learning.
Can we quantify the impact of interruptions from loudspeakers? This should be an area for further research. But having been interrupted in the middle of a lesson countless times myself, I can state pretty confidently such interruptions devalue learning. It’s hard enough as it is to maintain the attention of children without additional distractions.
School Design for Acoustics
What is it about a classroom or school that determines the quality of its acoustics?
One key factor is reverberation, which refers to the amount of time that it takes a sound within a room to fade. Too much reverberation intensifies and complicates spoken language, making it harder to understand. Imagine giving a speech in an unfurnished apartment with hardwood floors, as an example. Rather than hearing your words directly, listeners would also hear it reflecting off multiple surfaces, muddying your delivery. But some reverberation time (RT) can also be desirable, especially in a larger space, as sound needs to carry to listeners seated furthest from the speaker (ANSI/ASA, 2010). The more that reflective surfaces are covered over, RT is reduced, such as in a room with a carpet or with tapestries or pictures hanging off the walls.
There are recommended guidelines for how much reverberation is acceptable in a classroom environment. RT is generally measured in unoccupied classrooms through the creation of a sharp, sudden sound, such as by clapping two boards together or popping a balloon (there’s videos on the internet demonstrating measurement of different RTs in classrooms before and after acoustical treatments: search for something like ‘classroom reverberation time’). For hearing impaired children, less than 0.3 seconds of RT is recommended, while 0.4 to 0.6 seconds is recommended for general education classrooms (Mealings, 2016). In a 2001 survey by researchers from the Centers for Disease Control and Prevention, 13% of U.S. children were estimated to have hearing loss due to noise exposure (Chepesiuk, 2005). It therefore seems to me that we would want all our children, regardless of disability, to learn in classrooms with a RT closer to 0.3.
In surveys of school spaces across different countries, actual reverberation times varied dramatically from 0.2 to 1.9 seconds. To put this in context, a RT of 0.2 – 0.5 seconds is akin to what you would get in a recording studio, while a RT of 1.0 – 1.9 seconds would be akin to the amplified echoes of a concert hall. Reverberation time in large spaces is great for performances. But in a classroom, where both individual and group work is the norm, fluttering echoes make concentration and learning all the more difficult.
Fighting Noise in Schools
For schools that are already built and suffer from poor acoustics—the majority of our schools—there’s investments that can be made in acoustical treatment targeting floors, ceilings, or walls. As you consider which kind of treatment you or your school may want to invest in, bear in mind that absorptive materials work best when spread throughout a room, not concentrated in any one area (Seep et al., 2000).
Carpets and Floors
Carpets are one of the most direct methods to control sound levels. They also provide an area for class gatherings. However, carpets collect dirt and dust and need to be well-maintained, requiring more intensive upkeep than a laminated floor. And as anyone who has worked in a school knows, carpets don’t get replaced often, and rarely steam cleaned, if ever.
If you can’t get a carpet, reduce noise from the daily clatter of moving chairs and desks. While some teachers cut tennis balls and place them under chair and table legs, you may be inadvertently increasing indoor air pollutants. Instead, get “floor savers” (little felt disks) that adhere to chair and table bottoms. For a classroom with 32 chairs, this would cost around $75 at the time of this writing (packs of 24 for $15).
A better target for absorbing reverberation in classrooms is the ceiling, as absorptive ceilings can be more effective at absorbing sound than carpets (Shield et al., 2010). Some schools may already have some form of suspended acoustic ceiling tile, but those tiles may not be high performing enough to reduce reverberation times to adequate levels.
Swapping existing ceiling tiles with higher-performing ceiling panels can go a long way towards reducing reverberation time. Seep et al. recommend tiles of noise reduction coefficient (NRC) values 0.75 or higher (2000), while another source recommends NRC 0.9 or higher (Betz, 2015).
Not all spaces have suspended ceilings, however, and some ceilings are very high. Another method to absorb sound can be to hang acoustical treatments from the ceiling. These can come in various forms and colors, such as cubes, tetrahedrons, or waveforms, and are referred to by nifty names like baffles, clouds, and canopies. These decorative treatments could be well-suited for school hallways or entryways.
For a less expensive DYI approach, the American Speech-Language-Hearing Association recommends “suspending banners, flags, student work, and plants from the ceiling to contribute to the reduction of noise and reverberation” (ASHA, 2015). Your ability to do this will depend on the nature of your ceiling, of course.
Most classrooms have parallel walls, which means that sound reverberates between them. Even if ceilings are acoustically tiled and floors carpeted, walls can still reflect a lot of sound.
The American Speech-Language-Hearing Association recommends “placing mobile bulletin boards and bookcases at angles to the walls to decrease reverberation” (ASHA, 2015). Another expert also recommends hanging “portable corkboards” at an angle on the walls (Betz, 2015).
Portable corkboards and mobile bulletin boards can be pricey for an individual teacher to purchase, but the basic idea here is that any furniture, like bookcases, with a large surface area can be angled to help diffuse sound and keep it from reverberating back and forth between the walls.
It’s not clear how absorbent cork in general is for sound, but it seems to be a material that could work well as a DIY panel. Collect enough wine corks, and you can make your own corkboard! I don’t know how well these would work as sound absorbers (more research, please!), but might be worth a shot if you can’t afford professional paneling. Other low cost options may be furniture stuffing or denim.
Classroom furnishings in general can help to dull sound, but for larger spaces like science labs, cafeterias, or auditoriums, strategic placement of acoustical wall panels may be necessary. Acoustical panels are made of a foam or fabric that can absorb and diffuse sound.
Teacher and Student Actions
The simplest and most direct approach is to seat students who have the most trouble hearing the closest to the teacher (Klatte, M., Lachmann, T., & Meis, 2010). Generally speaking, students that have an identified problem with hearing will have this recommendation mandated as part of an Individualized Education Program (IEP), but it’s a good rule of thumb to bring students who seem to struggle with retention or following directions closer. It may be an auditory or visual issue that can be supported with proximity.
Think also about how much your instruction relies on auditory learning. Supplement and reinforce auditory learning with tasks and texts (edu jargon: plan for multiple modalities). Use visuals and gestures when speaking, and ensure that directions for tasks are provided on a chart visible from the back of the room or as a handout.
Be aware of the signal-to-noise ratio in your room. When the background noise increases, resist the urge to speak louder. Teach your students to recognize sound levels that are most appropriate for different tasks (i.e. whispers during reading time, “4 inch voices” during partner/group talk, across-the-room projection during class discussions).
As I was drafting this, I facilitated a professional learning session for teachers in a classroom on the historic DeWitt Clinton campus in the Bronx, and because all of this research was fresh on my mind, I was hyper-aware of the terrible acoustics of the room. The ceilings were high and did not have any acoustical tile. All it took was one pair of teachers having a side conversation to raise the overall background noise of the classroom.
When I found myself raising my voice, I spoke to my participants about the acoustical quality of the room to make us all aware of it, and I noticed that framing my request for one voice at a time in this way was also more effective. It depersonalized the refocusing needed during discussions or work time. Building a similar awareness with students in our classrooms can support collective ownership of sound levels in the learning environment, rather than making it incumbent on the teacher to constantly monitor and shush students.
In fact, why not teach students directly about the importance of the impact of noise in the places they learn and live? The NYC Department of Environmental Protection has free resources to teach students about sound and noise available on its website: http://www.nyc.gov/html/dep/html/environmental_education/sound_noise.shtml. There is a guide on sound mapping, and this could be done as part of an interdisciplinary project using tools for sound measurement. Student experiments measuring the sound levels in their own school and community can be an enlightening exercise for both students and the adults. For example, a group of 5th grade students in Alexandria, Virginia, discovered that “the decibel level in the cafeteria could reach an average of 101 decibels, equivalent to the noise in a subway station” (NIDCD, 2016).
If we want our students to become civically engaged citizens, advocating for their own needs and the needs of others, then the acoustics in their own classrooms would be a wonderful place to start.
Amplification systems could be of some benefit to both teachers and students, but if an amplified voice just reverberates around the classroom walls, it may lend itself to the creation of more noise. Amplification systems also tend to amplify only the teacher, not students, and asking students to pass around a microphone to speak is not an ideal workaround for every group discussion (Seep et al., 2000). Designing classroom walls and surfaces to dampen noise may be the wiser investment.
The best way to solve problems with acoustics is to prevent them beforehand, not correct them after the fact (Seep et al., 2000).And there is evidence that regulations of new school construction can have a positive impact on the acoustical quality of classrooms. In England and Wales, legislation introduced in 2003 required new school buildings to meet specifications for noise, reverberation time, and acoustical treatments. A study in 2015 that measured 185 schools across a range of representative secondary UK schools found that the amount of spaces that met the requirements doubled in those built after the regulations, compared to those built before (Shield et al.).
So regulations matter. Unfortunately, many schools are constructed with cost as the most important factor, and acoustics can be all too easily overlooked, despite their centrality to learning. Regulations that provide clear specifications for acoustical design would help to ensure that built spaces provide an environment where speech can be heard.
The good news is that the U.S. has a set of rigorous acoustical standards that could guide school design. In 2002, the Acoustical Society of America and American National Standards Institute published the American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, which were further revised and updated in 2010 (ANSI/ASA). For classrooms and other school spaces, they provide design specifications to address background noise, reverberation times, and more.
The bad news is twofold. First, these standards are not compulsory. Since the federal government does not collect and publish information on school construction, it is unclear how many schools built after 2002 comply, and furthermore, how many schools built prior to 2002 may be anywhere close to these standards.
Second, construction authorities already must adhere to a biblical amount of code, and they are not necessarily receptive to adding more costly and complex ones on top of it.
At the time of this writing, a clearer and narrower technical standard associated with reverberation time was proposed for inclusion in the International Building Code, a well-respected code created by the International Code Council and adopted by many states and municipalities (NRMCA, 2017). For reference, this proposal would establish a scope for technical criteria in Section 808 of the ICC/A117.1 – 2017 Section 1207, “Enhanced Classroom Acoustics” (ICC, 2018). This update will apply for new school construction when and where the code is adopted in 2021. But this highlights a key caveat: a state or municipality still needs to adopt that updated building code in order for it to apply and become enforceable — so we’re still kicking the can down the road.
What can citizens who care about this do? Instead of waiting for the updated International Building Code to be adopted, we can advocate for more rigorous acoustical guidelines to be applied now by our school construction authorities for all new school buildings.
And we’re still only talking about new school building construction. Noise abatement and quality acoustical treatment in older buildings becomes even more costly and complex.
Grant funding for schools is frequently targeted for items of more immediate concerns, like technology or musical instruments. But why not seek to gain capital funding for acoustical treatments for classrooms and cafeterias? The impact could not only be significant, but furthermore sustained over the course of life for the school building, impacting countless students and teachers.
It’s also important to remember from an advocacy perspective that acoustics are an accessibility issue. If a child is hearing impaired, their Individualized Education Program (IEP) should address the acoustical environment—this is especially important the younger the child is. But a child’s IEP is only an avenue for advocacy on a case-by-case basis. Advocacy to a public office of disability and to our public representatives is a broader way to tackle the issue, in conjunction with advocacy for individual students within the school.
Noise makes it harder for all children to hear, to read, and to remember.
Children in many classrooms miss 25% or more of what their teacher says each day due to poor acoustics.
When a space is of poor acoustical quality, it is more likely to become noisier once in use.
Poor acoustical quality not only impedes student learning, but furthermore creates costly teacher voice problems.
Reverberation times in classrooms should ideally be 0.4 seconds or less.
To combat noise in schools, we can:
Stick “floor savers” (little felt disks) on the bottoms of chair and table legs
Install or replace acoustical ceiling tiles with noise reduction coefficient (NRC) values 0.75 or higher
Install acoustical panels in cafeterias and auditoriums
Hang stuff from the ceiling, such as:
Acoustical baffles, clouds, or canopies
Banners, flags, student work, or plants
Place furniture and other large surfaces at different angles to the walls and ceiling to help diffuse sound
Support students in understanding and taking ownership of sound levels in their living and learning environment
Advocate for new school construction to adhere to ANSI or updated International Building Code guidelines for classroom acoustics
Seek funding for older school buildings to obtain professional acoustical treatment
Extra Credit: The Ecology of Acoustics
Schools leaders constantly scan the acoustical environment of their building. They can tell when an escalating voice may mean a fight is about to break out, versus when a class performance is about to occur. The subtle yet critical distinction between the emotional valence of kids having fun or experiencing crisis is something that becomes instinctual.
What about the cumulative types of sounds that kids make over time? What is the positive-to-negative ratio of words used? Can we identify the frequency and patterns of positive or problematic speech?
Soundscape ecologist Bernie Krause has recorded the sounds of natural ecosystems for nearly half a century. From his experience listening intensely, over time, to the sounds associated with specific places, he has developed a hypothesis that the health of an ecosystem can be gauged by the layered diversity of its sounds (Keim, 2014). According to this “niche hypothesis”—which he calls biophony—in a complex, diverse, and well-balanced ecosystem, each animal’s call finds its place within a tapestry of sounds, in the manner that the leaves of a thriving tree stagger themselves three dimensionally to best catch the light.
Conversely, in a damaged ecosystem, animal sounds thin out, devolving into extremes of either noise or silence. Due to the increasing noise of human traffic and industrial activity, animals sensitive to noise may have difficulty finding a niche in which they can be heard, thus reducing their ability to procreate and thrive.
In the ecosystem of a school, one hopes that every child’s voice will find its niche. Yet all too often, there may be more noise than signal.
Can we gauge the health of a school ecosystem through the tapestry of its sounds?
Is there a threshold that could be identified in the trends and types of school sounds, where we could intervene before problems occur? Could issues with school climate be identified more swiftly?
In many cities in the U.S., scanners are programmed to automatically detect gunshots, using a technology called ShotSpotter. Once gunfire has been detected, it is submitted to police dispatchers with a GPS location in order to be investigated (Smith, 2016). Similarly, scanners are now being embedded in natural areas that are in danger of illegal logging or poaching that can alert rangers (Hausheer, 2017).
Maybe one day automated scanners will monitor the sounds within school hallways, stairwells, and cafeterias, supplementing the instinctual sense of school leaders with acoustical data over time.
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I’ve realized that part of the reason I don’t post much anymore is that whenever I do think of something to write about (which is all the time), it just feels too big to dig into with the limited time I’ve got.
So I’m just going to start posting tidbits, whenever I can.
Here’s two awesome articles today that excited me because they are both about topics I care deeply about.
Goldhagen is an architecture critic and the author of the new book “Welcome to Your World: How the Built Environment Shapes Our Lives.” In it, she argues that buildings affect us in ways that go deeper than even most architects realize. They also provide windows into the minds that conceived them. “What can you learn about Trump from Trump’s aesthetics?” she asked. “Quite a lot.”