KidsAudiologist

Archive for the ‘unilateral’ Category

From this month NHS England (briefly known as the NHS Commissioning Board) takes over responsibility for commissioning specialist services for deaf children. This includes specialist implantable devices such as cochlear implants, bone anchored hearing aids and middle ear implants etc. Bilateral cochlear implants are currently and continue to be funded in line with NICE recommedations which children have a right to access under the NHS Constitution.

This month NHS England have announced their clinical access policies for bone anchored hearing aids and active middle ear implants. These are important because they relate to services that don’t have NICE recommendations and were previously commissioned locally by Primary Care Trusts and were subject to wide variation in provision. In summary:

Bone anchored hearing aids

  • are of safe and of proven benefit
  • should be provided in a specialist centre doing at least 15 a year. The team should include an ENT surgeon, audiologist, paediatric anaesthetist and speech and language therapist.
  • for children with microtia their care must be coordinated by a multidisciplinary team that can provide appropriate hearing and reconstructive support.
  • early intervention is vital and children born deaf should be provided with a bone anchored hearing aid on a soft headband until they are old enough for surgery.
  • funding will be available for children with bilateral conductive hearing loss to have bilateral bone anchored hearing aids if multidisciplinary assessment suggests that this would provide children with the best hearing environment in the classroom situation.
  • although bone anchored hearing aids would not normally be funded for children with unilateral deafness, an ‘exceptional case’ request can be made centred on information regarding the child’s development, audiometry results and communication needs.
  • and for the first time service providers will be expected to collect and provide audit data on request.

“Documents which have informed this policy – The National Deaf Children’s Society. Quality Standards in Bone Anchored Hearing Aids for Children and Young People. 2010″

Middle Ear Implants

Middle ear implants are a relatively new technology and very few children world-wide have been fitted with them. The evidence base is therefore almost non-existent at the current time. For these reasons it was not unexpected that active middle ear implants will not be routinely commissioned and will only be used as part of a recognised and structured clinical research project. However, they will be commissioned in the following limited circumstances:

  • Bilateral sensorineural hearing loss when conventional hearing aids have been used and found to be medically unsuitable due to conditions of the external ear.
  • Mixed hearing loss when conventional hearing aids have been used and found to be medically unsuitable due to conditions of the external ear and when a bone anchored hearing aid has been implanted and been associated with medical problems of the soft tissues or loss of fixture on more than one occasion.
Families who have a child with a mild, moderate or unilateral deafness frequently report that their child’s needs are poorly understood. This is often because the effect of their hearing loss may be more subtle than for those children with a more severe hearing loss. For example a mainstream teacher will find the child can hear them fine when working one-to-one with the child and not appreciate that the they can’t hear voices from further away and when there is background noise. This means that children have very reduced opportunities to benefit from hearing what is going on around them – incidental learning – and are therefore more likely to show delays in speech, language, educational, & social development than their normally hearing peers. Sadly, due to funding and capacity issues, local specialist support resources are often prioritised towards those children with more severe hearing losses so that training and awareness in schools may be low. Parents understanding and advocating for their child’s needs becomes even more important.
In 2010, NDCS was awarded a 2 year grant from the Department for Education under the SEN and Disability “Improving Outcomes” theme. We have been working with parents and professionals, providing specialist information and support on key barriers to achievement and to specific groups with a significant attainment gap. One strand of this work that I’ve been involved with has been to provide new information resources for parents that are available free to download – ‘Mild deafness’ and ‘Unilateral deafness’. This weekend I was involved in developing our first weekend for families of children who have a mild, moderate or unilateral deafness. All the deaf children were between 3 and 7 years old and they and their siblings appeared to have a great time occupied in the children’s activities sesssions. Parents attended sessions sharing their experiences, and heard from a young adult role model who grew up with moderate hearing loss in both ears. They also attended information sessions on audiology, technology, education, and NDCS events and services. 12 families attended and for 10 of them it was the first time they or their children had ever attended an NDCS event. Many had been told or held the perception that their child wasn’t ‘deaf enough’ to access specialist services, Disability Living Allowance, resources that help children develop listening skills, and even NDCS. A few families had shown an interest in learning sign language to help communication at times when their hearing aids couldn’t be used and to mix with other deaf children, but many had been poorly advised including that it would have a negative impact on their child’s spoken language development. This may have been one dimension of why families often hadn’t persued joining local groups and meeting other families with deaf children. Most of the children had never met another child that uses hearing aids and it was a real joy watching them playing together and making new friends ‘like them’ over the weekend. I believe the parents have all gone away feeling more confident that they understand their child’s needs and will be better able to make informed choices on behalf of and with their child.

So if you have a child with a mild, moderate or unilateral deafness remember that “NDCS uses the word ‘deaf’ to refer to all levels of hearing loss” and that all of our current services and events are open to you.

At a recent NDCS Family Weekend for families of newly diagnosed children I was reminded of a question I’m asked alot – is the newborn hearing screen accurate? And the parents most likely to ask are those whose child passed newborn hearing screening but was later diagnosed with a hearing loss. So is it? Or have these children been misdiagnosed?

I believe that there is an issue here but that it might not be what is immediately thought!

The goal of newborn hearing screening is to enable the identification of as many newborns as possible who do have a hearing loss (high sensitivity) but also exclude as many newborns as possible who do not have a hearing loss (high specificity). Depending on the type of screen carried out, around 15% of babies who are tested using otoacoustic emissions (OAE), and 3% of babies tested using automated auditory brainstem response (AABR) will be referred for further testing. Between one to two babies in every 1000 are born with some level of hearing loss in one or both ears, so we know that it is much more likely that a baby is referred from screening and found to have normal hearing than the other way round. But there is a real issue with information sharing between professionals, as well as between professionals and parents…

Only half the children with permanent childhood hearing loss are born deaf. The other half develop deafness during the first few months/years. There are therefore young children who passed newborn screening and diagnosed as deaf early in life that can look like an inaccurate or late diagnosis but may have actually developed the deafness post-screening. There are some common causes of childhood deafness that cause this, such as CMV infection and genetics, that are commonly believed to be congenital (from birth) but are actually progressive early in life. One of the reasons we test for unilateral (one-sided) hearing loss in newborns in this country is because we know that a proportion go on to develop bilateral hearing loss soon after so it’s important to monitor these babies and young children. Another issue is that the screen is designed to pick up moderate or greater deafness but this isn’t explicitly laid out to parents and therefore again parents feel misled if later their child is diagnosed with mild deafness (or maybe was born with mild deafness that progressed early). Some of this we have only begun to understand better in the last few years and since universal screening was implemented – in the past children were always diagnosed later and therefore assumed to have been deaf from birth.

Although the information leaflet that is provided with newborn screening clearly says that deafness can happen at any age, most people’s perception is that a passed screen = normal hearing. Parents continue to express concerns that they have problems accessing an audiology assessment for their child. A GP may fail to refer concerned parents because everything must be OK as ‘they passed their newborn test’ and Health Visitors who used to test babies at 8 months may now assume that there’s no need to be concerned because of the early screen.

Having said all this, there is of course always the chance of error or mis-diagnosis within the system, or a false report of passing the screen. In which case any concerns of the parents should be treated seriously and investigated fully. For other families it can be helpful to discuss the ‘aetiology’ or cause of their child’s deafness and that may help to understand how and why the hearing loss happened/progressed. NDCS publishes a great booklet that is free to download called Understanding your child’s hearing tests that includes a section ‘Medical tests used to help diagnose the cause of
permanent deafness’ with more information.

More than 9 out of every 10 chldren born with a hearing loss have hearing parents. It’s therefore entirely natural that early on they are going to ask “What can my child actually hear, what does it sound like for them?” They share a need to try and get to grips with this as part of the process of understanding what they need to do to help their child. It is a very difficult question to answer. Some of the things we know at this stage include the degree and type of deafness: we know how much volume is lacking for a mild (20-40dB), moderate (41-70dB), severe (71-95dB) or profound (95+dB) hearing loss, and we know that loss of hair cells in sensorineural hearing loss means that some natural processing that happens within the cochlea is lost – including the cochlea amplifier, pitch discrimination and the ability to recognise different sound levels (reduced dynamic range). We also know a good amount about the benefits and limitations of various types of hearing technologies that are used. Now more than any time in history, we know that almost all deaf children can perceive the full range of speech sounds with their hearing aids or cochlear implants. But we also know that they can’t do this as easily as hearing children and that no hearing technology can replace normal levels or quality of hearing.

So it’s relatively easy to mock up some simulations of what a hearing loss might sound like using some software to reduce the overall level of sound and filter out some of the frequencies that make up speech sounds. There are some good ones available online and my favourite is the Better Hearing Institute which has mild and moderate hearing loss in different situations. The NDCS also have a couple of examples that are specific to children in classrooms.

But there is a health warning about these simulations and that is that we don’t know, especially in the early days following diagnosis in young babies, what is happening beyond the ear and how well they can make sense of the sound they hear. Hearing, listening and understanding are sophisticated processes that are determined by a complex interaction between the physical properties of the ear as well as attention, memory and auditory processing (what happens when your brain recognises and interprets sound so that it becomes meaningful). The brain has the incredible power of plasticity in the early years and is continually moulding and learning from new experiences and sounds. As adults the brain is much less plastic and it takes much longer to adapt. This means that the experience of hearing and listening is hugely variable between individuals and is influenced by whether someone is born deaf or what age they became deaf, how long it was between developing a hearing loss and being fitted with hearing aids, their listening experience, and their cognitive and auditory processing abilities. Children born deaf and those who become deaf early in life experience deafness as the norm. Older children, teenagers and adults who become deaf have a very different experience of deafness to which they need to psychologically and physically adapt to. Much of what we understand hearing loss to sound like comes from adults who have previously experienced normal hearing levels. This is a particular issue when parents are considering a cochlear implant for their child for example. It is commonly reported that cochlear implants sound electronic, that they aren’t natural, and that voices sound like ‘a Dalek underwater’. This can be a devastating idea for parents considering this option but in fact when you speak to these same implanted adults later on they describe their implants as sounding very natural as their brain has acclimatised to the new sound. I recently chatted with a group of teenagers who all used cochlear implants and they agreed – “people think they sound like robots, but they don’t”. Just from listening to the voice quality of the thousands of implanted children, we can be certain that they do not experience this kind of ‘electronic’ sound. But to listen to this type of electronic simulation the best one I’ve found is Scientific American Frontiers.

Auditory Neuropathy Spectrum Disorder (ANSD) affects approximately one in 10 deaf children and causes distortion of sound and difficulty discriminating speech over and above what we would expect from the hearing loss alone. The level of distortion is highly variable from very slight to very severe and it is not measurable. So in young children we do not know early on how it will affect their speech and language development. Simulations of ANSD from mild to profound neuropathies can be heard here and make scary listening but again we know that with the right intervention children with ANSD are successfully using their hearing and using spoken language.

There are 10 million people in the UK have some degree of hearing loss and the majority of these people experience age-related deterioration of hearing. At the other end of the age spectrum there are just 45,000 under 18’s with a permanent hearing loss. Inbetween there are those adults who grew up with a hearing loss as well as those who have lost their hearing as an adult. My experience is that individuals (and their parents or family) use a wide variety of terms to describe their hearing level – deaf, hearing loss, partially hearing, hearing impaired, hard of hearing – and they rarely relate to their audiogram level. There are those people who associate themselves culturally with the Deaf community who we may traditionally think of as those who are profoundly deaf sign-language users. But there are also people who have developed a mild hearing loss for the first time who may tell their audiologist they are ‘stone deaf’ or ‘can’t hear a thing’ and this is their perception compared with their normal experience.

Every child’s hearing levels and hearing experience is unique and it is impossible for these types of simulations to represent how all deaf people process and experience sounds heard. But they are useful in giving the listener an understanding of the difficulties encountered and I particularly like those that can highlight the big differences experienced between listening in quiet and noisy environments and which are an important reminder of how much easier we can make life for children by improving their listening environments in school and elsewhere.

This weekend I had the priviledge to be invited to the final residential weekend for the current NDCS Youth Advisory Board (YAB) cohort. Wow, I mean just wow, what an amazing bunch of teenagers! I was doing some filming with them on retubing earmoulds, using radio aids with other equipment, and their experiences with cochlear implants, and the films will appear on the NDCS Buzz website soon. I had the chance to have a chat with some of them and had a read through their memory books of their year but you can have a read of their new blog for more details of the weekend.

But my main memory of the weekend will be about communication. These teenagers had a range of hearing losses from mild to profound; most were using a range of technology including hearing aids, cochlear implants and radio aids; and most had identified themselves as using one main communication preference prior to joining the YAB. In the last 20 years or so I have often walked into a room full of deaf kids signing with one another and this was no different. But some of these kids hadn’t signed a year ago at all – they had learnt it so that they could all communicate easier with one another. At the same time they almost all used spoken language and effortlessly switched depending on who they were chatting to. They were so flexible – it was much less about their own communication needs, as them adjusting to others communication needs! One of the teenagers had taken her mock oral GCSE in German last week, and another had passed both GCSE Japenese and BSL Stage II in the same year.

None of these kids are ‘mine’ or had been seen in my clinic but they all made me very proud to be an audiologist. There has never been a time in history when deaf children and young people had as many options, choices and opportunities available to them, thanks in part to the technology they’re using.

Christmas is that time of year when we traditionally eat too much, exchange presents, and get extended family and friends together. Whilst I’m not going to attempt any dietary or present buying advice, there may be readers who are going to be joining family or friends with a deaf or hearing impaired child in the family. You may not normally get to spend a lot of time with them or maybe they were very tiny the last time you saw them. The following tips will help make communication easier and more enjoyable for you both…

  • Most children who have hearing difficulty will use all kinds of visual clues to help them make sense of what is being said. They will watch your facial expressions and body language, and they may be watching your lips closely (lip-reading). So it’s really important to make sure you have the child’s attention before starting to talk, keep facing the child and try to maintain good eye contact. Try to get down on the same level as them so that they don’t have to look up to you all the time. And if you’re playing together allow some space so that they can see your face clearly. At Christmas the fairy lights can be very pretty and atmospheric but if a child has a hearing loss they won’t easily be able to follow what’s being said in a dark room so try to keep the lights on when you’re talking. And try not to stand with your back to a window as this creates shadow and makes it difficult to read your facial expressions or lipread.
  • Santa may be a lovely fellow who brings some great presents but with that bushy white beard he’s impossible to lip-read. If you’re sporting facial hair consider a festive trim. And don’t try to talk to the child at the same time as munching your way through the mince pies and Quality Street, or when hiding behind the Christmas edition of the Radio Times.
  • Background noise makes it really hard for a hearing impaired child to follow your speech and conversation in groups can be impossible. Since there’s probably going to be lots of conversation  going on around the dinner table try to make sure that any background noise that can be turned off, such as the looped CD of Christmas songs, is.  Make sure members of the group speak one at a time and visually indicate when a different person is speaking so that the child can keep up.
  • When you’re talking there’s no need to shout. This will distort your lip patterns but more importantly appear to the child that you are angry with them, potentially setting up yet another generation of traditional Christmas family feuding. So speak clearly, naturally and at a normal pace.
  • Mostly though, don’t give up! They may not know all the words you use so try a different word with the same meaning and use gestures to show what you mean. Encourage them to tell you if they don’t  understand.

However you celebrate, I wish you a very enjoyable festive period and happy New Year!

If you’re reading this after Christmas, why not contact the NDCS for a copy of their flyer or poster of tips Communicating with deaf children without references to slightly dysfunctional family dynamics (which may have more to do with the authors own rather than widespread experiences).

 

 

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.


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

  • 67,603 hits