When students, whether they be children or adults, are being educated in enclosed, classroom situations, it is essential that the intelligibility of speech is high; it is necessary for each student to be able to hear with adequate volume and understand with sufficient clarity. It has been shown by extensive research that there is a strong correlation between the acoustic conditions within teaching spaces and the levels of academic attainment for students. With a little thought, it becomes obvious that this would be the case.
With the teacher located typically at the front of the classroom and speaking in a normal manner, two conditions will come into play. These include the distance decay of the speech as it reaches the pupils sat furthest away, typically referred to as distance attenuation. Also, and importantly, the directed speech energy will inevitably reach different surfaces of the classroom spaces at different times which will include the walls and ceilings. Depending on the materials used within the classroom space, some of this energy may be absorbed, however some may be further reflected creating secondary reflected energy. Given the size and space of the room, this has the potential to impact how the sound is perceived. The sound energy and more specifically, the control of the reverberation within the classroom is critical. For students with Special Educational Needs (SEN), it is essential to ensure that classrooms have limited reverberation times and that speech is easily detected by all pupils within the classroom space. It is typical for new classrooms or conversions of classroom spaces, that the reverberation time is measured to ensure that suitable materials can be specified to help absorb reflected energy inside the rooms. Introducing ceiling tiles, wall mounted absorbers, vertical baffles or horizontal rafts can all assist in controlling the acoustic conditions within an educational setting.
Whilst the control of acoustic energy within the classroom is relevant, it is also important to consider other avenues of sound and how these make their way into the classroom space. The list is long and can include the following which are key design factors for acoustics and educational settings.
• Airborne sounds from adjacent rooms and/or teaching spaces. This is why separating walls and specifying the mass of these is key to ensuring that all educational spaces are kept contained.
• Impact sounds from classrooms above, the scraping of chairs and tables and general footfall must also be considered, as these have the potential to distract from what is being taught by the teacher.
• Sounds also need to be controlled from the external environment to ensure that the building has suitable mass and glazing to keep the outside environment outside.
• Competing adjacent spaces can also be a problem with an example being an active music room next to a space where quiet conditions are required.
• Folding/concertina partitions can also be a weak link in between classrooms.
• Where there might be plant to provide ventilation (heating and cooling) into the classroom spaces, this also requires careful attention to detail. The plant can not be so noisy as to distract the pupils, but equally, if the plant is serving more than one space with fresh air, then it is essential to ensure that one room’s sound is not easily ducted into another space. Attenuators are often introduced into plant systems to ensure that this is not the case and that pupils can pay attention to the teacher and subject in hand.
• Doors can also be a weak link where corridors or heavily trafficked areas might lead into a classroom. The specification of appropriate massing and door sets and seals to minimise noise ingress is key.
• Flanking sound. With older buildings, it might often be the case that walls have been made to partition off two spaces, however the partition might not reach the solid ceiling above, and it is quite conceivable that sound can travel over a partition. This is often the case in older buildings with a dropped ceiling.
• Increasingly, schools are turning to decarbonisation projects and using Air Source Heat Pumps to provide spatial heating, cooling and hot water. Such plant requires careful placement to ensure that the noise generated does not adversely impact the teaching environment but also does not impact nearby residential demises.
Acoustics within educational settings is very complex and requires a number of factors to be carefully considered to ensure that all of the above are considered at the planning design stage. The degree to which mitigation measures might be needed will depend on the nature of the students being taught as well as the disciplines being taught.
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At Acoustic South East, we specialise in school acoustics solutions to create optimal learning environments. Our expert team assesses and improves classroom acoustics by controlling noise levels, reducing reverberation, and enhancing speech intelligibility.
Whether you’re designing a new school or upgrading an existing one, we provide independent, expert advice to ensure compliance with acoustic standards and improve student learning outcomes.
To learn more about our school acoustics services, visit our website or get in touch with our friendly team today!
