Additional support for learning: sensory-inclusive learning environments - guidance

8. Acoustics, sound and hearing

8.1 Reactions to noise

Noise is known to deeply impact the ability of people to concentrate and absorb new information. It can particularly affect wellbeing, comfort and fatigue levels for people who have hyperacusis through hearing loss or have hypersenstivity often accompanied by a reduced ability to filter out unwanted sounds. It is often a key contributor to sensory overload. While loud impact noises can bother almost everyone, other people can be hypersensitive to different levels and types of noise and certain sounds can cause an anxiety or fear approach, known as phonophobia. This could include certain frequencies and lower volume, softer sounds like breathing, chewing (often associated with misophonia), a ticking clock or the continuous hum or whir of a fan (e.g. ventilation, ovens, computers). Conversely, noise that is self-controlled, such as small repetitive sounds generated by some stimming devices can be beneficial for some.

Sudden, or continuous loud sounds (such as hand driers or musical performances) can trigger balance (vestibular) challenges or cause bouts of tinnitus as well as triggering anxiety, meltdown or shut down. Learners who are D/deaf are particularly affected and can experience gaps in learning due to a noise or highly reverberant environment. A common symptom of inner ear damage is recruitment, where small increases in sound are perceived as much louder and become overwhelming.

For considerations of large open spaces, see also section 5.2 in this guide.

See PAS 6463 Table 2 for suggested acoustic values for different area types.

8.2 Background external noise

Opening windows allows in the sounds from outside, for example a railway, busy traffic, aircraft, agricultural machinery, construction noise or activities such as sports.

This could be offset by intentionally introducing some background sounds (sound scaping techniques) but always requires testing as some people with highly acute hearing (which includes many young children) may hear sounds above and below the normal anticipated frequencies. External features like organically shaped landscape mounds (berms), raised beds, and acoustic fencing could be considered in conjunction with advice from acoustic experts. Dense tree/bush planting may provide a visual barrier and provide some natural masking noise due to movement in the wind.

8.3 Activity adjacencies

Considering adjacencies from an acoustic and noise perspective, either in the design of a new building, or organisation of an existing building or the location of an outside space, can ensure high noise areas do not adversely impact areas of focus or calm. Physically separating noisy and quiet activities and spaces can reduce the need for further acoustic measures. It may be necessary to acoustically separate classrooms and collaborative spaces such as atria or halls, which can be very noisy and have hard surfaces which can cause excessively long reverberation times. Air handling units can be a constant source of noise and should be located to minimise noise transfer to occupied spaces.

Floor finishes – hard flooring can potentially create impact noise when it has no acoustic absorbency. Carpet or acoustic vinyl floor finishes will assist with reducing impact noise and carpet, in particular, will also aid sound absorption.

Where hard floor finishes are required, such as in laboratories, an impact resistant resilient layer installed below the floor finish helps to control impact sound transmission. D/deaf children, in particular, should not be seated near sources of background noise that can interfere with their hearing technology.

8.4 Acoustic absorbers

In some existing situations it could be useful to introduce mobile screens of acoustically absorptive material that can be put in place for certain activities or to divide spaces to reduce noise (subject to assessment by an acoustician). Robust wipeable acoustic materials are available that are impact resistant and these would be suitable for sports halls performance/assembly spaces and dining areas where damage is more likely through activities and the movement of equipment and furniture.

• Acoustic wall baffles, ceiling rafts or acoustic ceiling tiles may be good additions in problem areas;
• Furniture and soft furnishing can help reduce reverberation, and some items are specifically designed to absorb sound and could be added retrospectively;
• Adding soft finishes can help, such as curtains, floor cushions, rugs or even acoustic pads under desks and pads on chair legs to remove the risk of chairs scraping on a hard floor.

8.5 Noise source reduction

Removing unnecessary background noise can be helpful. Common issues are a constant buzz or hum from lighting, exposed pipes, or open plan spaces without doors, all of which can affect people who are hypersensitive to noise. Turning items off at the socket when not in use will avoid some discernible sounds, such as the low hum of a printer.

Suggested recommendations to consider with an acoustic consultant could include:

• Select low noise appliances. Hand driers in toilets are best avoided but if these must be provided, then low noise types are available. (Quiet Mark is an independent global certification programme associated with the UK Noise Abatement Society charitable foundation which certifies quiet products);
• Soft close mechanisms for cupboard doors and toilet seats or adding silicon rubber bumpers retrospectively can reduce slamming;
• Where PA systems are used to mark the end of lessons and these are loud and intrusive, consider less aggressive incremental melodic sounds or provide a subtle warning in advance so that noise sensitive people can prepare and perhaps wear noise reducing headphones;
• Where fire alarm sounders are used, it is important that they sound distinctly different to the end of lesson signal, for example potentially with a voice alarm for evacuation. A beacon that flashes as well as sounds will be helpful to people with profound hearing loss who may not hear the alarm at all. Expert advice should be sought in each situation;
• Fire and emergency alarm procedures that allow a few minutes for staff to verify the alarm is genuine are helpful in avoiding unnecessary loud alerts for false alarms.

8.6 Quiet times

It may be helpful to plan quiet times throughout the day when background effects or music are switched off and quieter learning and activity take place. Break times and movement between classes are some of the noisiest times of day but could be staggered, or acoustic considerations given to alternative routes.

Clarity

Background noise levels are reasonable, allowing important sounds to be heard e.g. PA system, communications etc.

Choice

Able to adjust fans, open a window, close a door. Range of busy and quiet spaces to suit individuals.

Calm

Good acoustics in relevant areas, keeping noisy areas away from quiet spaces. No hand-driers or other high noise devices.

Resources:

For technical information and standards on appropriate acoustic values, see:

PAS6463 section 10. (A table of recommended acoustic values for rooms is provided in PAS6463 Table 2).

Building Bulletin (BB) 93 Acoustic design of school’s performance standards (Scottish Government guidance (2007) supports design improvements based on Building Bulletin 93 (GOV.UK)

For further general guidance on assistive listening systems, see BS8300-2 s13.1 and Table D1.

National Deaf Children’s Society Acoustics toolkit:

Creating a good communication environment as an educator

Creating good listening conditions BATOD acoustic standards