When we speak, we push air from our lungs, which continues up through the neck via the vocal chords, which in turn vibrate and create sound. The sound continues on via the nasal cavity and oral cavity, creating sound waves that are released into the room. These sound waves are received by someone’s ears via the outer ear to the inner ear, where they are converted into electrical impulses. These continue to the brain, where the receiver hears. What is heard is not just a voice, however, but also what the room does to the voice of the sender. If the speech is interesting, the receiver hopefully starts listening, and if the acoustical conditions around the speaker are good, you are likely to remember more of what is said.
The cost of noise in education – listening and retaining information
Noise creates a great cost in terms of education. A study found that German classrooms have an average sound level of 65 dB, which is far too high. If you view teaching as watering the garden, poor acoustics means that some of the water evaporates rather than gets received by the flowers. Listening becomes a challenge, and teachers and students need to repeat themselves to get heard and listened to. The fact that humans are not great listeners from the beginning makes it more difficult – we usually only retain 25% of what someone says.
Listen to Julian Treasure speak more about the cost of noise below.
What is a sound classroom environment?
Teachers and students have three wishes in relation to sound and noise in classrooms. They want:
- Better speech perception. This is affected by the speaker’s voice and listener’s ears – and by the room acoustics. Good acoustics means that the voice can easily reach the listening ears, as the sound waves are direct and only pass the ears once; like they do in an outside environment. If you cannot go outside to teach, you can still optimise the internal environment to have improved acoustics. For example, you can place a book case in the class room, fill it with binders, and then remove every other cover. This creates a diffusion effect similar to the one in the forest.
- Better speaker comfort. Insert something that reflects sound above the speaker so he or she can hear and know that what is said can be heard by the receivers.
- Less noise. You cannot force children to be quiet, but by providing the right acoustic conditions in which to listen and learn, the teacher can focus on what matters: teaching.
Acoustic strategies – Five aspects you need to know
You need an understanding of the following five aspects to be able to create a good acoustic environment:
- What teaching method is used
- What technical devices are used
- What the building and rooms look like
- How the room is decorated
- Knowledge about the impact of noise on humans
The proof – The Essex Study
The Essex study (2012) stresses the importance of good acoustics in schools. The results showed that having acoustically treated rooms leads to:
- Less vocal effort needed from teacher
- Lower overall noise level (primarily for those with hearing impairment, but the situation was improved for all students)
- Better signal/noise ratio
- Better behaviour (students becoming quieter and behaving differently)
- Better teaching and learning possibilities
Listen to Adrian James speak more about the Essex study below. You can also read more about the study and its results right here on the Acoustic Bulletin.
This post has shared some of the thoughts and ideas around how to create sound acoustic environments in education, which were presented at the Sound Education seminars in 2012. The seminars were held in four different cities: Copenhagen, London, Münich and Stockholm. You can watch all the presentations here.