Acoustic Accessibility – 10 important things you should know
Acoustic accessibility is achieved when what is spoken is received by the listener at a volume that allows the words to be clearly heard and potentially understood.
- When a teacher talks to a class of pupils all but those with the most profound deafness will hear a voice but will not necessarily hear each word clearly enough to be able to know and understand what has been said.
- Poor classroom acoustic design, noise from both inside and outside the classroom, excessive reverberation, size and shape of the room can all be barriers to achieving acoustic accessibility.
- Most pupils with any level of deafness and pupils with Auditory Processing Disorders will struggle more to hear clearly what is being said in a classroom with poor acoustic accessibility.
- The quality of hearing of pupils with a moderate level of deafness often goes undetected in classrooms, leaving them struggling to understand what is being said. They rarely complain.
- All pupils sitting further from the teacher than the teacher’s voice will normally carry, its ‘critical distance’, will miss words, or parts of words eg prefixes, suffixes, that are spoken.
- Pupils are not able to consistently ‘fill in the gaps’ of what is being said to them if they miss words, until they are approximately 15 years of age due to their cognitive immaturity and limited vocabulary.
- Pupils with any level of deafness regularly underperform academically when compared to their peers and require excellent acoustic accessibility if they are to succeed at or above the same rate as their peers.
- Significant improvements in acoustic accessibility can be achieved by the installation of acoustic materials and soundfield / Classroom Audio Distribution (CAD) technology.
- The teacher’s voice needs to be at least 10 dB above the background noise, for hearing pupils, and at least 15 dB for deaf pupils in order to have good speech intelligibility.
- The use of assistive listening devices (see MESHGuide Assistve Listening Devices), for a deaf child or young person, can increase their acoustic accessibility by giving a good signal to noise ratio.
