How to Soundproof a School

So we'll be creating guides to soundproofing various locations like your home, school or office, what materials you need and how to deal with noisy neighbours/traffic/creaky old buildings etc, anything that is either annoying you, preventing you from getting your work done or upsetting your clients. We'll try to provide examples of what we're talking about, case studies and we're also happy to respond to any feedback you leave or questions you want to ask - Go ahead, don't be shy.

Recent studies have shown that many classrooms have poor acoustics. As a result, children with normal hearing are often unable to make out what is being said in class. Before 2003, Part E of the Building Regulations did not apply to schools. It now includes schools within its scope. It also requires sound absorption to entrance halls, corridors or hallways in multiple dwellings such as flats. All school buildings are now subject to detailed design checks and on-site inspections by building control officers.

Recent studies have shown that many classrooms have poor acoustics. As a result, children with normal hearing are often unable to make out what is being said in class.

Before 2003, Part E of the Building Regulations did not apply to schools. It now includes schools within its scope. It also requires sound absorption to entrance halls, corridors or hallways in multiple dwellings such as flats. All school buildings are now subject to detailed design checks and on-site inspections by building control officers.

Part of the sound from a teacher, the direct sound, passes directly to the ears of his/her pupils. Another part travels to the room surfaces and is reflected, eventually
reaching the pupils ears from many directions at close intervals: this is called reverberant sound. If there is too much reverberant sound, the pupil is still receiving the reflected sounds of previous syllables when he is trying to cope with the direct sound of later syllables.

The two then interfere, and speech is difficult to understand. The amount of reverberation is usually expressed as the reverberation time, which is the time taken for the sound to die away after its source has stopped. It is determined by the volume of the space and is capacity for sound absorption and is defined as the time taken for the sound to decay by 60 decibels.

It may vary from half a second in an ordinary living room to 8 seconds or more in a large assembly hall or gymnasium. Long reverberation times occur in large rooms with hard wall, floors and ceiling surfaces. Adding acoustic absorption panels or tiles will reduce the reverberation time and will improve speech intelligibility.

In classrooms and other rooms for speech, large amounts of fixed acoustic absorption are often required particularly where rooms have high volumes, as often
occurs in older buildings.

The location of acoustic absorption within a room is important. The traditional calculation of reverberation time assumes that the absorbent surfaces in a room
are reasonably evenly distributed. If this is not so, the reverberation time equation is not valid and undesirable local variations in the acoustics can occur, particularly in large rooms or halls. Large areas of acoustically reflective material can also lead to echoes, focusing and standing waves.

Where absorption occurs only on the floor and ceiling, for example in a solution employing acoustic ceiling tiles and carpeted floors, users may experience an over-emphasis on sound reflections in a horizontal plane. This often leads to 'flutter echoes' between walls, which result in the actual
reverberation time being considerably longer than the calculated reverberation time. A much better solution, especially in large rooms, is to distribute some of the
absorptive panelling on the walls.

Many hearing impaired pupils make use of low frequencies below 500 Hz to obtain information from speech. Therefore, for hearing impaired pupils to be included in classes alongside pupils having normal hearing, special care should be taken to minimise low frequency indoor noise levels. Sound absorbing panels offering very good sound absorption at low frequencies such as Echo Panel acoustic panels should be considered for these areas.

The Building Regulations Approved Document E also contains guidance on the addition of sound absorption to common areas in buildings containing multiple
dwellings such as flats.

These spaces are increasingly used in schools for a wide range of activities such as drama, parents evenings, meetings, exams, sports, audio/visual presentations etc. They have hard sound reflective surfaces and suffer badly from poor acoustics. Floors are normally wooden or vinyl and the walls are normally plastered or timber clad with concrete/plasterboard ceilings. A reverberation time of 0.8 to 1.2 seconds is required for assembly halls.

Typical solution is to line high level wall surfaces with Echo Fabric and, if necessary, add some Echo Panels on part of the ceiling.

These are the most numerous teaching spaces in any school and hence the most important. They tend to cater mainly for around 20 to 30 pupils and one
teacher. Sometimes there may be a teaching assistant. These rooms are reliant on the spoken word without any electronic amplified system. This is particularly important as some of the children in the class may have hearing impairment. The surfaces of classrooms can vary from school toschool. Some classroom floors have carpets, some have timber, some have vinyl or other surface finishes. Other may have a combination of these. Walls in the modern schools will generally be plastered but older schools may have brick or painted blockwork. Ceilings may be concrete, plasterboard or even suspended 'office' type ceilings. Reverberation time of less than 0.6 or 0.8 seconds is required for classrooms.

Acoustic solutions to these rooms can be the installation of Echo Panel acoustic panels in a horizontal band at high level on the walls and/or Echo Panel acoustic panels on the ceilings.

These rooms are designed to take a lot of punishment and all the surfaces are hard and cleanable. Floors are normally ceramic tiles or vinyl or timber. The walls are
mainly plastered and painted. The ceilings are a mixture of surfaces such as plasterboard, timber boarding, metal profiled decking and other surfaces.

Compared to other school spaces like classrooms, drama halls etc, children entering dining rooms feel free to let off 'steam' as they feel they are in a less formal area. It is a time for them to relax and play and joke with their friends during their lunch break. Hence dining rooms tend to be very noisy and the clatter of cutlery and screeching of chairs is very noticeable as well as the general verbal noise from the
children. It is important in these spaces that acoustic absorbers are kept at high level, well away from reach by hands etc. Echo Panel acoustic panels and Echo
Fabric acoustic wall panels are ideal for these areas.

Reverberation time of less than 1.0 seconds is required for dining rooms.