class room sound field system
Clear speech shouldn't be a barrier to learning.
Since the first research project on sound field systems some 20 years ago, there have been more than 50 additional studies testifying to the benefits of class rooms fitted with Sound Field Systems.
It has been noticed that children in the amplified classrooms attain higher speech perception and spelling scores, their attention to the teacher is for longer periodsof time and they score higher in academic achievement tests than children in non-amplified classrooms.
The Linkx IRA 89 is a complete sound field system designed for installation in class rooms. Each sound-field system kit consists of an infrared wireless microphone worn by the teacher, which is transmitted via loudspeakers placedstrategically around the room.
The system increases the teacher's voice level and also decreases the distance from each child to the teacher's voice, which removes the problems associated with reverberation.
In an experiment conducted by NAL, the use of sound-fieldsystems resulted in a 41 per cent increase in the rate of attainment of educational indicators during the terms the systems were installed.
This was averaged across all children in the classes and across reading, writing and numeracy skills and occurred despite most of the children having no problems with their hearing.
What is the Science behind a Sound Field System?
As with a magnetic field, sound also weakens by the square of the distance. The sound wave amplitude drops off by the square of the distance. This is calculated by the distance being multiplied by itself.
For example, the child sitting at a teacher's side one metre away hears very well. The child sitting two metres away hears four times less. Four metres away, eight times less. And if the child is ten metres away 10 X 10 = 100 times less!
From the practical aspect, have you ever had someone talk directly in your ear? It's loud. In the class environment, achild sitting directly in front of a teacher 1-2 metres away, will hear very well while a child sitting at the back of the class may be day dreaming.
This is not just experiential. The cause may be based on science. An experienced teacher will often use this by moving the distracted child near them, allowing the child tohear better and remain focused on the lesson.
However, the problem still exists with others who are seated at the back of the room or furthest from the teacher.These children, at a distance from the teacher are off task,more easily distracted, or looking elsewhere more frequentlythan those who are closer.
- Children spend 45% of the school day engaged in listening activities
- Children's auditory processes aren't fully developed until their mid-teens
- Even in an acoustically 'good' classroom, children 'receive' 83% of a teacher's voice 'signal' when they sit inthe front row; 66% in the middle rows and only 55% in the back row.
- Children do not perform well in noisy environments compared to adults
- The ability to listen in noisy environments is not developed until adolescence
- The average primary school student misses 25% of what a teacher says Children need a quieter environment and a louder signal in which to learn. Hence this is what Sound Field Systems set out to achieve.
Evidence is continuing to accumulate regarding their positive impact upon literacy, academic accomplishments and classroom behaviour. There is less "acting up" or "tuning out" problems.
Classroom systems have been shown to be a cost effective way of minimising special education referrals and services.
With a high prevalence of hearing loss among indigenous communities here in Australia, sound-field amplification systems are helping many Aboriginal children in the classroom hear their teachers.
According to Professor Harvey Dillon, Director at the National Acoustic Laboratories (NAL), the research division of Australian Hearing, many children are unable to hear their teachers properly due to reverberation and general classroom noise.
While classroom sound-field systems were initially designed for the "special needs" children, experience has demonstrated that children who hear normally in the classroom are also benefiting.
Presumably, while these children have no difficulty understanding the teacher in an un-amplified classroom, theyare nevertheless able to do this with much less effort and more certainty in an amplified classroom.
Clearly, even children with normal hearing have to hear well in order to learn well!
What is a Sound Field System?
The sound-field system consists of an infrared wireless microphone worn by the teacher, which is transmitted via loudspeakers placed strategically around the room.
The system increases the teacher?s voice level and also decreases the distance from each child to the teacher's voice, which removes the problems associated with reverberation.
Sound-field systems offer benefits to children with conductive or mild hearing loss who do not wear hearing aids. They also benefit children with middle ear infection, those who speak English as a second language and those with an auditory processing disorder.
Benefits of a Sound Field System
- Children with fluctuating middle ear hearing loss
- Children of non English speaking backgrounds
- Children with auditory processing difficulties
- Children with ADHD
- Children with learning difficulties
- Studies show that all children benefit from hearing the Teacher better because of the improvement in signal to background noise ratio.
- Cost effective way of improving room acoustics
- Can be used to interface other audio visual equipment within the classroom
- Does not stigmatise children with normal hearing
- Does not require cooperation from the child.
The teachers responses to the systems are almost uniformly positive. They appreciate being able to teach all day without straining their voices. This is not a trivial advantage.
In one large scale study, it was found that 20% of the teachers suffered from some sort of active voice pathology, with 70% reporting voice problems in the past that caused them to miss work and that impaired their teaching effectiveness.
In two laryngological practices, teachers were the most frequent occupation identified representing proportions of 20% and 16% of the total caseload.
Another by-product of this is the rise in OH&S claims made by Teachers.