Captions and Soundfield in the Classroom

What is a soundfield?

Soundfield systems aim to evenly distribute the sound of the teacher’s voice, around the room, by means of a microphone and a speaker or speakers, so that all pupils can hear the teacher clearly. Research has shown that the use of soundfield systems can improve concentration of pupils, improve academic performance, keep noise levels down, improve behaviour, and especially benefit those with specific learning or sensory needs.

Ordering soundfield systems:

AV SOLUTIONS
221-12448 82 Ave
Surrey, BC V3W 3E9
Canada

(604) 599-0333

Email:  support@avsolutions.ca

Why is this important?

Listening at school:

• “Listening” is the cornerstone of the educational system.
• Children spend up to 70% of their school day listening.
• Children are the biggest source of noise in the classroom.
• If a child cannot clearly hear and attend/listen to spoken instruction, the entire premise of the educational system is undermined
• Canadian Study Shows: 1 in 6 words are not understood by the average 1^st grade student due to excessive background noise and poor classroom acoustics
• Students who are most challenged by excessive noise and reverberation are under the age of 13, especially those in kindergarten and first grade
• Adults need a SNR (Signal to noise ratio) of +6 in order to hear intelligibly in a noisy environment. (The signal needs to be 2x louder than the background noise)
• Typically developing children who are not DHH need a SNR of +15 to +20 dB which is around 10x louder than the background noise.
• By age 9 students are able to start filtering out background noise, shift attention and focus.  This continues to develop into adulthood.
• Noise presence impacts: speech perception, attention, behavior, and overall classroom performance
• Children who are educated in noisy classrooms tend to give up faster when faced with learning challenges.
• Teachers are at 20 times the risk of average workers for permanently damaging their voices

Children, who primarily learn through listening, do not have the language skills or knowledge to fill in the blanks when they do not hear every word, making noisy classrooms a significant barrier to learning. Students who are particularly at risk for “missing words” are:

• Children learning in a non-native language (ESL, immersion)
• Children with learning disabilities
• Children with behavioural or attentional difficulties
• Hard-of-hearing children with permanent hearing loss or temporary loss due to ear infections

As teachers we learn how to speak loudly and project our voices… however,

• There is a critical distinction between speech being heard as AUDIBLE ….versus speech being heard as INTELLIGIBLE
• AUDIBILITY means that the speech is “heard” – but not heard clearly enough to distinguish specific speech sounds
• AUDIBILITY is carried by vowels – high energy, low frequency speech sounds. The low frequencies of 250 Hz and 500 Hz carry 90% of the power of speech, but only 10% of the intelligibility.
• INTELLIGIBILITY means that the listener heard clearly enough to identify critical word/sound distinctions.
• INTELLIGIBILITY is carried by consonants – low energy, high frequency speech sounds. The frequencies of 2000 Hz and 4000 Hz carry 90% of the intelligibility of speech, but only 10% of the power of speech. They are very weak speech sounds.

Here’s a visual: Remember – Volume does not equal clarity!

Here is a poem with only the vowel sounds – try saying the sound for /a/ or /e/ as loud as you can – I’m sure you can say it quite loud! Can you understand the poem?

Here’s the same poem with only the consonants.  Try saying the sound for /t/ or /s/ loudly, can you?  Can you understand the poem?