Numerous local and world-wide studies suggest classrooms are greatly affected by acoustic quality. Below we look at acoustic effects on learning environments and how to absorb unwanted noise.
The design of a classroom needs to take into consideration the effect acoustics can play on the learning environment, as competing background noise can cause students to misinterpret key words, phrases and concepts.
A study conducted in United States Classrooms reported that the speech intelligibility rating is 75 per cent. This means, on average, every fourth word in the classroom is misheard (Seep, Glosemeyer, Hulce, Linn, Aytar, 2000). Background noise – in particular irrelevant speech – interferes with children's ability to hear their teachers or one another, therefore affecting their ability to learn.
Many teaching spaces in older schools were not designed for the current teaching methods and are often found to have poor acoustic qualities. The traditional approach was for a teacher to stand at the front of the class whereas today, teachers prefer to move around. This involves working with groups or individuals and requires their voices to be heard from all parts of the room.
Evaluating the acoustic suitability of your classrooms is the first important step to ensure that unsatisfactory acoustics do not adversely affect learning in your school. The Ministry of Education strongly recommends that you:
The signal-to-noise ratio is the ratio of the teacher’s voice to the ambient noise. The recommended minimum necessary for students to hear efficiently in a classroom is +12 to +15 dB (+20 dB is preferred when there are students with hearing impairments). This means that if the background noise level is, say, 55 dB, the teacher would need to speak at 70 dB, which is almost shouting. The louder the background noise, the louder the teacher must speak so the students can hear clearly.
ABSORBING UNWANTED NOISE
All materials have some sound absorbing qualities; the sound that is not absorbed is reflected. In buildings, the sound-absorbing characteristic of a material is rated as the Noise Reduction Coefficient (NRC) and is measured at voice frequency. If the reverberation time of a room is too long it can be reduced by adding other materials.
The Ministry of Education and the Acoustical Society of America suggests achieving the best acoustics for learning by installing inlay acoustic ceiling tiles and a suitable acoustic wall covering.
Interior Acoustic companies like Autex Industries understand that all classrooms and educational areas are different and require unique solutions to provide the optimum level of noise reduction.
With over 40 years’ experience in the education sector, Autex Industries have continued to strive for innovation in interior acoustics by continuously improving the performance of their 100 per cent Polyester, environmentally-friendly products. A non-toxic alternative to mineral and Fibreglass products, Autex’s premier Interior Acoustic solutions are renowned for their durability and performance, whilst being safer, cleaner and eco-friendly. Autex’s wide range of benefits makes them the perfect complement to the education industry.
Because teachers voices best travel in spaces that are acoustically well designed, it is recommended that schools follow the appropriate stages set out in the Ministry's Property Management Handbook. It is also best that they ensure their architect or property manager consults with an Acoustic Consultant or one of the Account Managers at a company like Autex Industries.
Following these guidelines will develop classrooms that meet the needs students and provide a comfortable environment for the teachers to work in.
Some photos in this article are from a recent project with Loughborough University located in the United Kingdom, Kaipara Westmount Campus located in New Zealand and Avalon School located in the United Kingdom.
Seep, Benjamin., Glosemeyer, Robin., Hulce, Emily., Linn, Matt. Aytar, Pamela. Classroom Acoustics – A Resource for Creating Learning Environments with Desirable Learning Conditions, August 2000.
Ministry of Education & BRANZ. Designing Quality Learning Spaces: Acoustics, (2007).