Driving positive educational outcomes

Smart specification of interior acoustic solutions

As modern educational practices have evolved, so too have modern learning spaces. It is expected that contemporary learning environments should be set up to facilitate collaboration and interaction (meaning high levels of conversation), but this is not always the case. Studies have shown that when it comes to acoustic performance, Australian classrooms are well behind the mark^iv.

However, designers and specifiers can make a difference in this area. Interior acoustic solutions are a high-performance means of reducing reverberation and other noise within educational environments, creating better learning outcomes for children. They are lightweight and easy to install, meaning they can be retrofitted within existing spaces as well as specified for new construction.

This whitepaper will examine, in detail, the issues around poor acoustics in educational environments, their impact on children, and how smart specification of interior acoustics solutions can fix these problems.

The impact of poor acoustics in educational environments

The majority of students’ time in classrooms is spent listening to the teacher or interacting with each other. However, excessive noise and reverberation in classrooms often make it difficult to hear what is being said. This results in what is known as a low Speech Transmission Index (STI); put simply, the acoustics of the space make it difficult for students to determine what is being said. An Australian study found that more than 90% of Brisbane classrooms failed to achieve recommended STI levels, meaning that children would struggle to adequately decipher information in these environments^v.

The ability to recognise speech under conditions of noise, or noise combined with reverberation, continues to develop until the teenage years, meaning that younger children are particularly susceptible to the harmful effects of unfavourable listening conditions^vi. Research indicates that acoustical problems in schools lead to decreased learning outcomes for students through impaired speech perception and listening comprehension. In addition, these issues are exacerbated in children with existing learning difficulties, hearing impairment, and English as a Second Language (ESL)^vii.

However, these issues can extend further than listening. Noise-induced disruption can also have an impact on students’ abilities to perform non-auditory tasks. Excessive reverberation has been linked to poor performance in verbal tasks, and high exposure to ambient noise with a reduced reading level^viii. This shows that acoustic issues can negatively affect children’s wider cognition and brain function at a time that is crucial for the healthy development of neural pathways^ix.

In addition, poor classroom acoustics can have detrimental impacts on teachers as much as students. Teachers’ voices are considered tools of trade, and damage or loss of voice from excessive shouting poses serious Occupational Health and Safety concerns. In fact, voice disorders are considered one of the major hazards of school teaching^x, impacting teachers’ ability to form relationships with staff and students, as well as resulting in lost productivity and greater sick leave.

The need for acoustic-focused learning environments

The traditional idea of a theatre-style classroom with students’ desks facing a teacher at one end is, for the most part, obsolete. 21st-century education practices have evolved to an immersive, fluid style that is heavily integrated with technology as a means of preparing students for the realities of the modern world. Classrooms are now ‘learning environments’ centred around collaboration, problem-solving, and interaction, with a focus on equitable access. These endeavours are all rooted in the development of strong language and clear communication practices, highlighting the need for good acoustic design.

A detailed 2019 study conducted acoustic surveys of 33 classrooms in Brisbane and found significant deficiencies in their acoustic performance. Unoccupied sound levels are used as an indication of ambient noise pollution. These ranged from 25-50 dBA, meaning 25% of classrooms were above the recommended 40dBA maximum^xi. In addition, classrooms showed reverberation times (RTs) of up to 1.26 seconds, meaning 79% of classrooms were above the suggested 0.6-second maximum^xii. Occupied sound levels were as loud as 64.8dBL, and STIs as low as 0.35 (on a scale of 0-1), meaning 92% of classrooms failed in these regards. When compared with similar studies using datasets from Sydney and broader Australia, findings were consistent with the results of the Brisbane study^xiii. Overall, the high percentages of classrooms not meeting the recommended performance requirements for beneficial learning environments highlights the need for better acoustic solutions in these environments.

Interior acoustic solutions: high performance, low fuss

Noise can never be eliminated entirely, and nor should it be. The goal in acoustic design is to create a space that offers a high signal-to-noise ratio; that is, that the signal (in the case of classrooms, most often a teacher’s voice) can be heard clearly above background noise.

In the educational context, noise typically comes from four sources:

the intrusion of external noise
noise generated by building services (such as HVAC systems)
noise transferred between individual spaces including impact noise
control of reverberation times to enhance speech intelligibility

Autex’s range of interior acoustic solutions

Autex’s range of interior acoustic solutions are ideal for use in Australian educational, commercial, hospitality, and retail applications. Made from 100% polyester fibre and backing, they have no chemical binders and are certified low Volatile Organic Compounds (VOCs). They are manufactured using a minimum of 60% recycled materials and are resistant to colour fade, making them a durable and long-lasting solution for educational spaces.

Autex’s panel and Peel ‘n’ Stick products are lightweight and easy to install, with a large range of bespoke and customisable ceiling products – such as the Frontier™ and Horizon™ systems – also available. For further information on product ranges, installation, maintenance, or to discuss the bespoke needs of a particular project, designers and specifiers can contact their local Autex specification manager.

Part of designing for optimum acoustics

Autex’s range of interior acoustic solutions are ideal for use in Australian educational, commercial, hospitality, and retail applications. Made from 100% polyester fibre and backing, they have no chemical binders and are certified low Volatile Organic Compounds (VOCs). They are manufactured using a minimum of 60% recycled materials and are resistant to colour fade, making them a durable and long-lasting solution for educational spaces.

Autex’s panel and Peel ‘n’ Stick products are lightweight and easy to install, with a large range of bespoke and customisable ceiling products – such as the Frontier™ and Horizon™ systems – also available. For further information on product ranges, installation, maintenance, or to discuss the bespoke needs of a particular project, designers and specifiers can contact their local Autex specification manager.

Part of designing for optimum acoustics is the shape and design of the structure itself; whether rooms are large or small, have high ceilings or low, and what construction materials are used. For example, wood and concrete have different acoustic properties. However, many Australian schools are housed in buildings as old as 100 years, meaning that structural changes are not possible. Interior acoustic solutions can solve problems in these circumstances, as well as in new builds and contemporary designs.

Interior acoustic solutions absorb noise, preventing it from being reverberated within a room, whilst also providing a thicker membrane to protect from ambient, airborne, and structure-borne noise.

They provide particularly effective noise reduction in the region of 1kHz-4kHz, which is the region most sensitive to the human ear, and the region most occupied by the human voice.

Interior acoustic solutions are frequently supplied as tiles or panels, making them easy to transport and easy to install. Some are available with simple yet strong adhesive backing, making them easy for people with basic trade experience to install. Where possible, specifiers should opt for 100% polyester fibre interior acoustic solutions for education projects. In addition to providing excellent acoustic performance, polyester fibre is non-toxic, non-allergenic, and contains no irritants, making it safe for use around children.

Interior acoustic solutions offer a versatile, customisable, functional aesthetic for educational design applications. They are available in a wide range of standard colours, with custom colours available on request. Their hook-and-loop receptive surface means they can be used as staple or pinboards, or have things hung from them using Velcro™, including children’s artwork in education spaces.

Regulations and guidelines

The Building Code of Australia (BCA) does not offer specific recommendations for educational facilities. It does, however, outline performance requirements as they relate to specific building types; class 9b buildings include public spaces such as kindergartens, childcare centers, schools, and universities^xiv. This may serve to assist specifiers with specific information relating to minimising airborne and structural noise transfer due to construction elements like Heating, Ventilations, and Air Conditioning (HVAC) systems, but will not provide guidance with the specific mechanics of acoustic treatment for learning spaces.

Specifiers may draw from AS/NZS 2107:2016 Acoustics - Recommended design sound levels and reverberation times for building interiors, which contains acoustic design criteria for building interiors and provides^xv a useful baseline for performance. Again, this does not speak directly to the specific requirements of educational facilities so it should be used as a guideline only. There are, however, State-based guidelines that must be adhered to. For example, the NSW Educational Facilities and Guidelines outlines mandatory parameters on acoustic indicators such as Reverb Times, impact sound insulation, and more^xvi. Similarly, the Victorian School Building Authority’s Building Quality Standards Handbook outlines deemed-to-satisfy provisions for onsite sound reduction measurements, amongst other things^xvii. Specifiers should contact reputable acoustics experts to discuss best practices, and what solutions would work best for their particular project.

Autex – our story

For over 50 years, Autex has been a market leader in the manufacturing and development of textiles and advanced fibre technology. Beginning in New Zealand as a manufacturer of jute-based carpet and expanding its operation to Australia in 1991, Autex has stayed at the forefront of advances in technology to become a central innovator in textile engineering. Autex now offers a wide range of innovative and sustainable acoustic textiles to meet the ever-changing needs of the contemporary architecture and design industries.