Better acoustics, better learning

Effective teaching and learning often comes down to effective communication. That’s why the sound environment of your classroom or learning space is so important. 

Students learn by listening, observing and interacting not only with teachers and educators, but also with each other. Suboptimal acoustic environments can quickly become a problem for educators as poorly soundproofed classrooms or learning areas can create distractions and disruptions. 

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Issues with noise and distraction may be especially noticeable in younger students, as children are more sensitive to noise when building listening comprehension. 

Additionally, too much disruption and noise may be overstimulating and stressful for children. The World Health Organisation (WHO) has noted that excess noise might exacerbate unwanted behaviour like irritability and aggression. As school is where children spend most of their time, addressing suboptimal acoustics could improve overall wellbeing as well as improving learning outcomes. 

One common measure of classroom acoustics is to record reverberation time. This is defined as the time taken for a sound to fade to 60 dB after the sound source stops. A higher reverberation time means teachers must raise their voice to be understood. Proper acoustics therefore have implications for educator wellbeing as well as children. 

A good acoustic environment will have a shorter reverberation time. This can be achieved by installing sound-absorbing materials like padded ceiling tiles, carpet and acoustic wall-panels. Soft furnishings like beanbags, pillows and cushions can also help absorb sound. 

Another benefit of having sound-absorbing materials is to reduce the Lombard effect. This effect can often be observed during discussion time, where children’s voices become louder and louder to ensure they can be heard over one another. A good acoustic environment mitigates this effect as speech is intelligible at a lower volume – teachers and educators can be understood without raising their voice, and volumes at discussion times are kept to a reasonable level. 

Learning environments outside of the classroom, like gymnasiums, auditoriums and halls can be extra challenging in terms of acoustics. Indoor sports surfaces and hardwood floors tend to be loud and can make squeaks and echoes when used. High ceilings also contribute to echoing. A solution favoured by many schools is acoustic panels. They can help with sound absorption and make spaces truly multifunctional.  Skilled installers can identify the best areas to install panels and banners so maximum sound absorption is achieved with minimal cost. Removable features such as rugs and curtains can also help to improve a space’s functionality, so it can be used for assemblies, teaching and learning, as well as sports games and performances. 

Schools should also consider acoustics when building new structures. Acoustic considerations could range from the position of the building – is it close to roads, other classrooms, or high-use outdoor spaces? – to building materials. Carpeted, hardwood and linoleum floors all have implications for acoustic performance.

Rob Jones, Technical Manager at Autex Acoustics said Australian state and territory education departments have mandatory standards in place to ensure appropriate acoustic objectives are achieved “Acoustic engineers are regularly engaged to test learning environments and confirm that relevant performance criteria are met.”

“To achieve the standards set by education authorities, measurements can be taken to determine the appropriate acoustic material to be fitted in a given space. For example, rooms used for collaboration and general learning have different guidelines for target reverberation times than smaller spaces.”

To reduce reverberation, acoustics products with a Noise Reduction Coefficient (NRC) are typically fitted. “NRC ratings are used to quantify the absorption of a surface. A rating of 0.00 would mean a surface is completely reflective, while an NRC of 1.00 would signify that as an average of the mid frequencies between 250hz and 2000khz. 100 percent of sound that impacts a surface is absorbed and nothing is reflected back into the room,” Mr Jones said. “This is where high-performance products such as acoustically rated pinnable and velcro receptive linings can be employed to meet statutory requirements, help enhance learning outcomes, and create a healthier overall learning environment.”

Large spaces like gymnasiums can be used effectively with longer reverberation times but are prone to noticeable flutter echoes due to their size. “Numerous studies have measured the noise levels in school gyms at being consistently above 80 dBA and often reaching 90+ dBA during team activities.  These spaces can have noise levels close to those of busy industrial factories, meaning that OHS requirements should be considered for staff who spend many hours per day teaching in these areas.

“Other specialist spaces like auditoriums and music production  present challenges due to their use for activities that produce more varied acoustic environments. These spaces benefit greatly from careful initial planning, in consultation with an acoustic engineer, as sufficient volume and correct geometry is required for them to function.”