Category Archives: Education

Why Schools Need Good Acoustics

Sonya Myers

Sound expert Julian Treasure previously discussed how acoustics in the workplace are key to worker productivity and health. But how does that apply to the educational environment? How does noise affect students and teachers in the classroom?

Acoustics in Education

Bad acoustics in schools can be a big problem.

In a typical classroom, noise levels average around 65 decibels (dBs) — the threshold for serious health damage with long-term exposure. Higher noise levels have proven negative effects on health. For students, it can lead to lower academic performance since students have to work harder to understand their lessons. And for teachers, higher noise levels can mean a loss of voice from talking louder to be heard, and a higher risk of heart attack1 caused by a sustained increase in heart rate over time.

Clearly, something has to be done to make schools a better acoustic environment for everyone.

Solutions for Acoustics in Schools

Luckily, designing and retrofitting schools for acoustic benefit is not as difficult as it may seem.

Solutions such as replacing regular ceiling tiles with acoustic panels, or installing sound absorbers on classroom walls are viable approaches to the noise problem. But one of the most effective methods of improving school acoustics is sound-reducing flooring.

Acoustic Benefits of Flooring in Schools

A floor that reduces 30% of airborne noise is a great acoustic fix for schools. When it comes to flooring, carpet with an acoustic underlayment would be best in classrooms, but but luxury vinyl tile (LVT) with Sound ChoiceTM thanks to its durability and easiness to clean. Acoustic standards like Quiet Mark help separate flooring products with real acoustic benefit from other, less sound-reducing products.

Acoustics Case Study: Dawson County High School

The benefits of better acoustic flooring came to life at Dawson County High School in Dawsonville, Georgia. When school staff and students returned for the new school year, they were greeted by inviting updates to the main building.

New Interface carpet tile and LVT replaced the cold, noisy VCT floors in classrooms, hallways, and offices. The changes have not gone unnoticed. “People say it feels a lot less institutionalized, more like home,” says Scott Morgan, director of facilities and maintenance for Dawson County Schools. “The LVT makes the most difference. Everybody loves it. There are two things everybody talks about. That it’s softer on the feet and somehow it just helps with the sound.”

Dawson County High School classroom with Interface LVT

Dawson County High School classroom with Interface LVT

Download the entire case study to learn more about how Interface flooring created a better acoustic environment for Dawson County High School here.

Why Good Acoustics in Schools are Important

For those who spend the majority of their days in school environments, acoustics matter. Research shows that quieter classrooms improve academic performance, reduce stress for teachers, and better student behavior. A good classroom experience leads to increased productivity. And, it creates a better quality of life and improved sense of well-being for teachers and students alike.

The benefits of good acoustics in schools are numerous. Designers, administrators, and facility managers who are responsible for education environments should be paying attention.


1. Tiesler, Gerhart & Oberdörster, Markus. (2008). Noise – A Stressor? Acoustic Ergonomics of Schools. Building Acoustics. 15. 249-261. 10.1260/135101008786348690.

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What is Quiet Mark and Why Does it Matter?

Julian Treasure

Sound – especially sound in the spaces where we work – affects us far more than you might think. When it comes to designing interior spaces, acoustic considerations are often put aside or completely ignored in favor of purely visual aesthetics. However, condemning office workers, hospital staff, students and teachers, guests in hotels and even people in their homes to bad acoustics and the resulting high noise levels is simply unacceptable. This is because noise adversely affects well-being, effectiveness and happiness.

Understanding how sound affects human health is vital for architects and interior designers. Likewise, knowing how to measure sound and apply acoustic standards like Quiet Mark to consumer products will help designers and industry to transform how we feel about and respond to the spaces we inhabit.

Measuring Sound

When airborne sound meets a physical barrier, the barrier will have any or all of three effects on the sound.

How sound can interact with surfaces

Reflect

Reflection is when sound bounces off a surface back into the room. Hard surfaces reflect more sound than soft ones, so rooms with mainly hard surfaces tend to be louder.

The sum of all the reflections in a room is called reverberation. Large spaces with hard surfaces have long reverberation time (RT), which is the time it takes for a sudden sound to die away. Where good speech intelligibility matters, as in a classroom or a meeting room, RT should ideally be under half a second. In most social spaces (including open plan offices), it should be well under one second.

Absorb

Absorption is when sound energy is transformed into heat energy – usually by a soft surface ¬– and disappears. The absorbency of a material is noted with a number between 0 and 1, where 0 is complete reflection and 1 is complete absorption.

Two measurements for absorption which are similar but not directly comparable are the US-based sound absorption average (SAA) and the increasingly universal weighted sound absorption coefficient (αw aka Alpha-w). For simplicity, the International Standards Organization has created sound absorption class (SAC), which groups Alpha-w’s into brands from A (most absorbent) to E (least absorbent).

Transmit

Transmission happens when sound passes through a surface and can be heard on the other side. Most surfaces will reflect or absorb some sound, so not all the sound reaches the other side; this reduction is called attenuation. Attenuation of 10 dB means that sound seems half as loud on the other side.

Sound transmission in buildings

How sound is transmitted in buildings

The US measure of attenuation for airborne sound is called sound transmission class (STC) while the international measure is Rw. Both are dB averages of attenuation across a range of frequencies in dB.

The Quiet Mark Standard

While the above sound measurements are helpful for assessing the acoustical properties of a product, they are calculated in laboratories and can be wrongly interpreted when it comes to complex, real-world installations. That’s why a standard for noise performance in practical real-world applications can be very helpful – which is exactly what Quiet Mark sets out to achieve.

The Quiet Mark Logo

The Quiet Mark Logo

Quiet Mark is the international award program for recognizing excellence in low-noise technology and in solutions to unwanted noise. Associated with the U.K. Noise Abatement Society, Quiet Mark encourages companies worldwide to prioritize noise reduction within the design of everyday products, machines and appliances, giving consumers and industry alike a trusted mark of approval that can help transform the aural environment for the benefit of all. Companies with Quiet Mark-certified products include Dyson, Whirlpool and Bosch.

What differentiates Quiet Mark from other standards of sound measurement is that consumer products are tested in the environment where they’ll be used. For example, lawnmowers will be tested outdoors, dishwashers will be tested in a kitchen and vacuum cleaners will be used on a range of different surfaces. And because acoustic design is constantly advancing, Quiet Mark annually re-evaluates the products bearing its label.

Managing Noise with Flooring

One of the best ways to mitigate the effect of noise in indoor environments is through flooring. With carpet this is obvious because we intuitively know that soft surfaces are quieter.

Acoustics: Sound on Soft Surfaces vs. Hard Surfaces

However, hard flooring is catching up as both an aesthetically pleasing and acoustically effective option. Now, even Interface’s fashionable LVT performs acoustically very well with its Sound ChoiceTM backing, which carries the Quiet Mark label.

Lesson learned: Any floor can look great and improve acoustics at the same time.

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The True Cost of Noise

Julian Treasure

Dead silence can be an intimidating working environment.

Some sound in any workplace is generally desirable: pleasing background sounds like the gentle, indecipherable babble of colleagues speaking, one’s own choice of music or perhaps the sounds of nature coming through an open window. However, much of the sound in typical workplaces is undesirable: ringing phones, electromechanical noise, other people’s music and so on. We call this undesirable sound “noise”.

It’s important to have a thorough understanding of how this unwanted noise affects people in working environments and how best to improve those spaces with optimal acoustic adjustments.

Understanding how sound works

Sound wave

Sound is simply audible vibration conducted through a medium. In built spaces, there are two forms of conduction.

Airborne sound comprises sound generated within a room and transmitted through the air. Typically, this includes people talking, typing, walking and moving objects; phones ringing; noise from heating, ventilation and air conditioning (HVAC) equipment; printers; and sound/music systems.

Structure-borne sound comprises sound generated by any physical impact on the building and transmitted through the structure itself, which typically includes footfalls in the office above, vibrations from heavy equipment such as an HVAC plant, and impact sound like drilling or hammering in adjacent rooms.

We measure the quantity of sound in decibels (dB), a logarithmic scale where an increase of 10 dB is perceived as a doubling of the sound level, or a reduction of 10 dB as a halving. 30 dB is very quiet – for example, a bedroom at night. A typical office is around 50-60 dB.

Open office layout

A poorly designed open office is a recipe for bad acoustics.

The problem with noise

People spend a lot of their time in office spaces, where noise negatively affects worker productivity, health and satisfaction. To put it simply, this means that noise is bad for business.

Noise disturbs concentration.

According to Gensler’s 2013 Workplace Survey, people spend over half their working time in offices doing tasks that require focus. Most workers struggle to concentrate in open plan environments that were designed purely for collaboration. While people can habituate to constant, unvarying noise, interruptive noise severely detracts from worker productivity. According to Professor Gloria Mark of UC Irvine, it takes people 23 minutes to regain their focus after every significant interruption!

Noise damages health.

There are well-established links between long-term exposure to noise and coronary illness and stroke, as well as stress, high blood pressure and other conditions. The noise in question does not have to be overwhelmingly loud: research shows that the danger level is just 65 dB, which is often achieved in lively offices and especially in social spaces like cafés and canteens.

Noise damages communication.

Most people are familiar with the cocktail effect, where it’s impossible to understand the person talking to us in a group because of the noise of everyone else talking. Bad acoustics create more noise and thus impede people’s ability to understand one another.

For more information on the negative effects of workplace noise, take a look at the video below:

Solving the noise problem with good acoustics

All too often, modern architects and designers use hard materials because they look clean and stylish, and are durable and easy to clean. However, because the designers often have little or no training in acoustics, they don’t understand the effects of this kind of design. Bad acoustics increase noise levels dramatically – and the louder the noise, the greater the negative impacts.

In contrast, research shows that well-designed acoustics improve effectiveness, well-being and happiness for the people in working and living spaces. Good office design that takes into account visual aesthetics, sustainability, value for money and acoustic effect can achieve the perfect balance for the health, effectiveness and happiness of workers.

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