KidsAudiologist

Deaf children and road safety

Posted on: November 22, 2011

This week is Road Safety Week in the UK and so today’s post is inspired by our Benefits Appeals Advisers who support families with Disability Living Allowance tribunals and who are frequently challenged on what difficulties deaf children have and why they require additional supervision near traffic, especially as the majority are using hearing aids or cochlear implants and therefore have ‘corrected’ deafness.

Clearly, deaf teenagers and adults don’t remain a hazard in traffic and develop terrific coping mechanisms such as taking extra care to visually check for vehicles before crossing roads, and perhaps utilising their peripheral vision more effectively than hearing people. But these skills take time to develop so what do families need to know when their children are young?

Firstly are limitations of the hearing technology and what even the best hearing aids or cochlear implants can’t do. Parents often report that their child appears to be startled as if they didn’t notice a lorry or train approaching and this is probably an effect of the limitations of the microphone pick-up range, coupled with a reduced dynamic range. Microphones pick up sound at an optimal distance of just a few feet. This means that any sounds that have come from further away may have ‘bounced’ off other objects on the way (reverberation). This means that sounds can get distorted and makes it very difficult to judge distance or direction the sound is coming from. Hearing aids are programmed so that they amplify sounds within the wearers ‘dynamic range’ (the quietest sound a person can hear and the loudest sound they are comfortable with). However, because the dynamic range for most deaf people is reduced, the speed at which sounds grow from quiet to loud is quicker. Additionally, microphones are often affected by wind noise outside too obscuring what the wearer needs to listen to, but the programming of the hearing aids should prevent uncomfortably loud sounds getting through to the listener (eg lorries passing). Additionally, hearing aids are limited to the frequency ranges of speech and therefore sounds outside those ranges and heard by hearing people aren’t available (think for example about the restrictions on hearing music which has a much wider frequency range than speech). So what hearing and deaf people are hearing are quite different because of the features of the hearing loss and properties of the hearing aid.

Secondly is the limitations of the hearing nerve pathways – after all hearing isn’t all about the ears. It’s also very much about the brain and the clever things it does with the sound it receives and a hearing aid has almost no effect on this aspect. The brain can focus on what we want to hear and filter out alot of unwanted background noise but has a much harder time doing this when the sound input is not as good as normal. This means that the brain is going to have a harder time when sound has come via a hearing aid, the aid has amplified background noise, and the auditory pathways between the ear and brain are not be as developed as they should be due to the hearing loss and poorer input. The brain is also responsible for ‘localisation’ or working out which direction a sound comes from and this is important in judging speed and direction of traffic. To do this well the brain needs to have consistent and equal sound input from both ears and this would be the goal of programming and persuading deaf children to wear their hearing aids all the time. Filtering and localisation are skills which develop as we get older (young children are very bad at it and it normally naturally develops with age, deaf children may never fully develop them). More important reasons why early identification, good quality hearing aid fitting, and consistent hearing aid use are vital to enable deaf children to develop these skills well.

Advertisements

3 Responses to "Deaf children and road safety"

A child who is deaf attends my nursery I am looking to buy a road safety dvd sing and sign if possible, can you help?

I’m afraid I haven’t come across a DVD on this topic but I would advise contacting Forest Books http://www.forestbooks.com/ who specialise in resources on deafness and deaf issues – if there is something available they will know about it!

i complety agree my son is deaf and was late diagnosis his road safety is dreadful he doesnt understand bout holding hands wben his freinds can run ahead he is based on visual at yimes when i manage get him wait with me at road he doesnt want cross until he sees a car i have pay taxis evdrywhere as i dont want walk fear of his life to big pushchair aNd reins if doesnt want hold my hand he want be like his friends run ahead i cant afford get taxis all time so sometimes i just dont go out at all i dread going out makes me nervoius reck

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Twitter Updates

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 42 other followers

Blog Stats

  • 71,518 hits
%d bloggers like this: