“I can’t hear myself think!” The compelling case for quiet classrooms

Education theories abound about the best set-up for classrooms. As a parent, I know different school systems, principals, teachers, and families have strong and divergent views on the topic. As a speech pathologist, my chief concern with classroom set-ups is whether they help kids to understand what they’re taught – especially kids with speech, developmental language and other communication difficulties.*

So what does the peer-reviewed research evidence tell us?

Let’s start with the obvious.

To learn, kids need to understand what they are taught

Often, especially in the early years, information at school is communicated by the teacher and others in spoken language: in speech.
Some researchers think that kids spend up to 65% of their school day listening to spoken language (Palmer, 1997).
Historically, many classrooms had terrible acoustics (Knecht et al., 2002). For example, my primary school (built in the 1870s) was a red-brick, Victorian-era classic, with high ceilings, wooden desks and chairs, floorboards and lots of other hard surfaces. Noise tended to bounce around our classrooms like a squadron of possessed squash balls.
Some new schools are designed with good acoustics. Some older schools have been retro-fitted with carpets and soft furnishings to improve acoustics. But many still aren’t.
Now here’s the main point: compared to adults, kids have more difficulties understanding spoken language – speech – in noisy places (e.g. Grandell & Smaldino, 2000; and Cruckley & Scollie, 2012).

Why do kids struggle to understand language in noisy places?

Noisy places have a negative effect on language comprehension and cognitive processes such as working memory (e.g. Osman & Sullivan, 2014).
As we explain in more detail here, working memory is a system that stores and processes information temporarily – like a mental sketch pad. We’ve known for a long time that working memory can be reduced by:
- internal factors: e.g. attention issues, or hearing loss; and/or
- outside factors, e.g. background noise, or the complexity of language used by the speaker (Siegel & Ryan, 1989).
More recent research tells us that outside factors, in particular, have negative effects on a child’s oral language comprehension in school settings (Swain, Friehe, & Harrington, 2004).

What does “oral language comprehension” mean?

People with typical hearing are always processing sounds around them. Some of these sounds (e.g. of tyres screeching, a fire alarm, or a snake’s hiss) get our attention for good reason – our survival might depend on responding quickly to them. Others, like the neighbour’s leaf blower on a Sunday morning, contain little or no information – they are essentially meaningless “noise”.
Most of us are wired to pick up on speech sounds, especially when the speech sounds are conveying messages to us. When people talk – when they combine speech sounds to make words and sentences – they are usually giving us (listeners) a message – sending a signal. Our ability to pick up, process and understand that message – the “signal” – is called “oral language comprehension”. It’s also called “oral receptive language”**.

The many parts of oral language comprehension

Oral language comprehension is really complex: it involves lots of skills, including the ability to process:
- phonological information (e.g. speech sounds, syllables, stress, intonation);
- grammatical information (e.g. different sentence types); and
- prior knowledge and language content (including knowledge of vocabulary and relationships between words),

to make inferences about the meaning of a message.

Language comprehension skills range from recalling facts (main ideas and details), to making inferences (filling in the dots), to evaluating facts (language reasoning). Some researchers have identified five key parts of comprehending oral language:
- listening for the main idea;
- identifying the facts and details;
- making inferences and reasoning;
- understanding the vocabulary; and
- extracting and understanding the most important/relevant messages (Bowers et al., 2006). For convenience, in the next section, we’ll call these the “Main 5”.

Noise levels affect oral language comprehension: the evidence

Evidence is mounting that noise can have a negative effect on oral language comprehension. For example, there is evidence that:
- noise can affect a school-aged child’s ability to follow oral (spoken) instructions (Klatte et al., 2010); and
- increasing background noise and reverberation negatively affects school-aged kids’ story comprehension (Valente et al., 2012).
Noise seems to affect each of the Main 5, but to different degrees. For example, studies of school-aged children have shown that:
- “extremely adverse” noise affects identifying the details, reasoning and understanding of the message more than listening for the main idea and vocabulary (Schaefer et al., 2013); and
- performance on oral language and working memory tasks is significantly poorer in noisy places than in quiet ones. In particular, noise affects kids’ reasoning, detail identification, understanding, and vocabulary results (Sullivan et al., 2015 – see citation below).

But don’t some kids thrive in noisy classrooms?

Yes. The interesting question is why.

Too much noise affects everyone’s comprehension abilities. But different children are affected to different degrees:

Children with better working memories perform better on language comprehension tasks than children with poor working memories. This suggests that kids with larger working memory capacities are better able to compensate when noise is present.
Children with larger vocabularies performed better on language comprehension tasks in noisy places than children with small vocabularies. This may be because kids with large vocabularies have more cognitive resources to draw on and can use their working memories more effectively when listening in noisy places,

(Sullivan et al., 2015).

Why does noise affect some comprehension skills more than others?

There are two logical explanations:

the most affected skills require more brain power and rely more on working memory. Noise makes it harder to draw on cognitive resources like working memory; and
noise made some parts of the message hard to hear or inaudible.

They are not mutually exclusive: both factors may play a part (Sullivan et al., 2015).

Clinical bottom line

Noise has a significant effect on working memory and oral language comprehension at school. Children perform significantly worse on tests of working memory and oral language comprehension in noisy classrooms, compared to quiet ones. In particular, noisy places hamper the ability of kids to recall details, define vocabulary, reason, and to understand oral messages. This has important implications for schools and other places where children learn (including speech pathology clinics).

Limited vocabulary skills and working memory capacity may contribute to poor oral language comprehension in noisy places. This has important implications for teachers, speech pathologists and other professionals working with children with deficits in these areas, including when working with many children with developmental language and learning disorders.

Related articles:

Principal source: Sullivan, J.R., Osman, H., & Schaefer, E.C. (2015). The Effect of Noise on the Relationship Between Auditory Working Memory and Comprehension in School-Age Children, Journal of Speech, Language, and Hearing Research, 58, 1043-1051.

* As a speech pathologist, I’m also concerned about the effects of noisy classrooms on teachers’ and students’ voices. But that’s a topic for a separate article.

** Confusingly, oral language comprehension is sometimes also called “listening comprehension” or “auditory comprehension”, or the fiercely debated auditory processing but these terms are less precise. What I’m most interested in is kids’ ability to understand spoken language.

Image: http://tinyurl.com/y84zdscs

Hi there, I’m David Kinnane.

Principal Speech Pathologist, Banter Speech & Language

Our talented team of certified practising speech pathologists provide unhurried, personalised and evidence-based speech pathology care to children and adults in the Inner West of Sydney and beyond, both in our clinic and via telehealth.