It hasn’t always been the case that the acoustic considerations have been taken into account during the design of school classrooms. In recent years, however it has become more and more common knowledge that an acoustically healthy atmosphere facilitates learning.
Range of Acoustic Needs in the Classroom
Classrooms have unique acoustic requirements. Noise created by a large group of chattering children should ideally be absorbed, while the voice of the teacher should carry across the whole room, so that it can be heard by the students clearly and easily. Fortunately, from an acoustic management point of view, the nature of the situation is such that the teacher will generally be sitting or standing in the same place every day as she delivers her lesson. This means that the room can be set up with acoustic panels and other measures in place for a consistently pleasing acoustic result.
Distorted Sound with Poor Acoustics
If, for example, the wall at the back of the room is a hard surface, this can create a chaotic sound situation, making it difficult for students to concentrate. The voice of the teacher practically bounces off the hard surface at the back and starts moving back across the room. These sound waves subsequently get mixed up with the teacher’s next instructions. The solution is often to line the rear wall with thick acoustic insulation panels specially designed to absorb sound, enabling the next sentence to be received without undue distraction.
Whole Class and Small Group Instruction
Following the whole class introduction, the teacher often moves to a different part of the room. She may move to the floor to work with a small group of children or she might need to monitor students at their tables. If the rest of the acoustics are set up optimally, she is then able to provide assistance to individual and small groups of students, without disturbing the other children as they complete their work.
Impact of Fittings and Furnishings
The materials used to line walls and ceilings have a big impact on the acoustics of the room as does the absence or presence of carpet on the floor. The nature of the furniture also impacts acoustic reverb. Any soft absorbing materials on chairs will help to absorb echos, (although the impact is minimal) whereas hard plastic chairs will exacerbate the problem.
Teachers working in old classrooms lined with polished floorboards often find that several small group discussions among students can quickly escalate to a noise level that is unbearable as children end up shouting to be heard. Some are more creative than others and end up hanging up their own acoustic insulation in the form of curtains, fabrics and tapestries, and lining the floor with rugs to reduce the noise that is reverberated across the room.
One of the considerations of teachers taking outdoor lessons, on the other hand, is ensuring that they can be heard, as there are fewer surfaces to echo or amplify their instructions, and the sound easily dissipates into thin air.
Considerations for the Best Acoustic Insulation Solutions
In modern day teaching, interaction between students and teachers often happens in more informal settings. Educational acoustic designers and consultants should take into consideration the facets of the room, along with its intended use before recommending the amount, type and positioning of sound insulation in NZ schools.