The acoustic design of a classroom has the ability to boost or hinder student learning. Behind acoustic perception is architectural design, which ultimately decides how sound waves interact within a room. Elements like room size, room shape, and surface treatments influence acoustics and effect both students and teachers psychologically while they are communicating within a space. Suitable acoustical design in classrooms and other learning spaces enhances speech clarity and limits background noise to protect speech quality. Poor acoustical design can result in excessive noise that is disruptive to the learning process and may negatively affect speech perception, student behavior, and educational outcomes. When creating a learning space, we often disregard the importance of sound, and in doing so, we negate something very powerful. In order to provide students with the best learning experience possible, we have to take acoustic design into consideration and create with the intent to use sound to our advantage.
Acoustics are even more important for those who experience hearing loss than those who do not.
Suitable Acoustics for All Types of Hearing
Perfecting acoustics in a traditional classroom or other learning space is vital for both students who hear and who are deaf. Acoustics are even more important for those who experience hearing loss than those who do not. Any kind of noise that occurs within the learning space can cause disruption and will limit a student’s ability to focus on the lesson or activity at hand. Classroom noise includes any auditory disturbance that interferes with what a listener wants and needs to hear. These disturbances include:
- Noise from outside the building - highway traffic, playground noise
- Noise from within the building - children walking and talking in the halls, class bells, noise from other classrooms
- Noise from within the classroom - children's voices, mechanical noise from the air conditioning system, or technology used in the classroom
These sources of noise are the most common when it comes to classroom
learning, but most likely aren’t things we think about every day. Noise is subconsciously in the background of everything we do, and that’s why it is so easy to forget about. Most of us do not realize the negative effects of poor acoustic environments.
The Behavior of Sound
Sound waves radiate in all directions from a source until they come to an obstacle, which is typically a wall or another large structure. The intensity of a sound wave is a measurement of perceived loudness. The frequency of a sound wave is a measurement of perceived pitch. Both the intensity and the frequency of the sound wave will affect the sound, which is called surface interaction. When sound waves strike a surface, one or more of the following can happen:
- Transmission—sound passes through the surface into the space beyond it.
- Absorption—the surface absorbs the sound.
- Reflection—the sound strikes and bounces off of the surface. Reflected sound can result in echoes, which can interfere with hearing and understanding speech. There are discrete echoes, such as when the teacher's voice is continually bouncing off the back wall of a classroom, and there are flutter echoes, such as when a sound bounces rapidly between two flat, hard surfaces.
- Diffusion—the sound strikes the surface and is scattered in many directions.
Each one of these sound waves is unique and contributes to everything we hear. The way these sound waves behave in a learning environment influence every single interaction that occurs in that space.
Studies show that children with autism are highly sensitive to noise. A study from the National Library of Medicine discovered that from 30% to 90% of people with autism either ignore or overreact to ordinary sights, sounds, smells or other sensations. Among children who took part in the Simons Simplex Collection autism research project, about 68% had unusual sensory interests and 65% were sensitive to noise.
It is difficult to pinpoint why people with autism experience this sensitivity. Everyone is different, and every person with autism is going to have a different auditory experience. Not every sensory sensitivity is consistent with everyone who has autism. The National Autism Association (NAA) teamed up with the Interactive Autism Network (IAN) to research auditory sensitivity in autism and how noise might trigger anxiety for autistic people. If a noise is very bothersome to some autistic children, it may result in an unsafe situation for them. Some autistic children may run away from a situation if a noise is too overwhelming for them, or they may try to harm themselves or others. The IAN study explored strategies used by parents of noise-sensitive children. Most people avoided their child's trigger sounds and took quiet breaks with their child to lessen anxiety. However, about 30% of the parents said that the noise sensitivity led to social isolation by limiting their child's ability to take part in family, community or school activities. This fact alone suggests the deep influence that noise can have on certain people and how noise in the classroom can hinder learning success.
The ANSI/Acoustical Society of America (ASA) has ways to measure sound so we can understand how sound waves interact with surfaces, room sizes and more. The ASA also has standards for classroom acoustics so that education acoustical consultants can detect problems in a space. An acoustical assessment can include formal noise, reverberation and behavioral speech measurements. Speech recognition scores, teacher and student report forms, changes in student behavior and changes in student achievement scores are all things that will be considered to determine the adequacy of the classroom for listening and learning.
Poor acoustical design can result in excessive noise that is disruptive to the learning process and may negatively affect speech perception, student behavior, and educational outcomes.
The Right Acoustics for Your Classroom
Acoustical design begins when a space is being created. While it is easier to incorporate appropriate acoustic materials at the beginning of the construction process, it is always possible to make changes at a later date. If your classroom has some acoustical problems, there are changes you can make to improve the environment for students. When making improvements, take background sound levels, mechanical noise and exterior noise into consideration, and make sure that partition design is part of your classroom and the adjacent areas. Also, remember to keep all students in mind – those who can hear, those who are deaf, and those who experience autism as well as other behavioral issues. The simplest changes can end up make the biggest difference in the cognitive abilities of students.