KidsAudiologist

Posts Tagged ‘hearing aids

They’re popping up everywhere and are chosen for their status providing renewable and clean energy – wind farms. Earlier this month I was asked if I could answer a couple of questions about how wind turbines may impact on the hearing, and hearing aid / cochlear implants, of local residents. I have to admit to not really knowing anything about them so I put the question out on Twitter too…

… and although I didn’t get any responses that answered the question I did get some from other users who said they’d be interested in what I found out. So here’s a summary of what I learnt after some research, but I’m still learning so do add any comments with further evidence if you have it.

Q 1. Is there is any research on the implications for deaf people with hearing aids of living near to turbines?

A. No. There is no research, literature or other evidence (that I can find) of any positive or negative impact on hearing aids, cochlear implants or their wearers living near wind turbines. I can find two statements written by members of the public saying that turbines cause problems for hearing aid / cochlear implant users but cannot find any fuller description, case study, or evidence as to why this should be.

and

Q 2. Can you offer a professional opinion about the impact on of the turbine on a young person’s hearing and possible damage?

A. What I have established in relation to wind turbines and the ear/hearing:

  • There is no evidence that the noise generated by wind turbines causes hearing loss, and wind turbines are not loud enough to cause hearing loss.
  • It is known and widely acknowledged that wind turbines generate significant levels of infrasonic acoustic energy (noise that is below the frequency range that the human ear detects as sound).
  • There is some limited lab-based research evidence  (such as this) that suggests infrasonic sound (vibration) may cause some disruption or abnormal stimulation of the inner ear (cochlea and vestibular system) that may form the basis of the symptoms of ‘wind turbine syndrome’. These symptoms include tinnitus, vertigo, disturbed sleep, headaches, memory and concentration deficits, irritability and anger, fatigue and loss of motivation.
  • Wind turbine syndrome is not experienced by the majority of people living near turbines. The data may be difficult to establish as those closest to the turbines (ie those who rent land to the energy companies) are often motivated to be positive about turbines due to financial incentives, and/or gagging clauses in contracts that prevent them saying anything negative about them. But many of the symptoms can also be explained by other factors such as stress and annoyance etc.
  • Planning guidelines in the UK says that turbine noise should not exceed 5 decibels above background, ambient noise. A wind farm produces a noise of about 35-45 decibels at a distance of 350m. Rural night-time background noise typically ranges from 20 to 40 decibels. No indoor levels are specified.
  • Most hearing aid wearers would be able to follow a close one-to-one conversation easily in this level of background noise.
  • In terms of background noise levels and the effect on hearing aid wearers it would be my opinion that if these levels were accurate and maintained, that outdoors the natural noise of the wind would be likely to be more of a hindrance than the turbine noise to the hearing aid or cochlear implant wearer (wind blows over the microphone and is amplified, wind also carries voices away from the listener etc). Indoors it is unlikely that these levels of background noise from outside would be significant or even heard. These background noise levels are certainly a lot lower than the average town or city dweller experiences most of the time.

I have located just one document for audiologists “Wind-Turbine Noise; What Audiologists Should Know” (Audiology Today, Jul/Aug 2010). It includes lots of information on the acoustics, infrasonic vibration levels, and the potential health problems that could be associated with wind turbines (such as tinnitus and vestibular disturbance) but is clear that the levels generated aren’t loud enough to cause noise damage and makes absolutely no mention of problems associated with hearing aids or cochlear implants.

There is probably still much we don’t know about the turbine technology, as well as the potential impact on the technologies on the human body. At the moment audiologists serving populations in areas where there are wind farms should be aware of potential health problems that patients may complain of. But I can find no evidence of any significant negative impact on existing hearing loss or on any hearing aids or cochlear implants that are worn.

Further reading

Wind turbine sound and health NHS Choices, January 2010

Scientist Challenges the Conventional Wisdom That What You Can’t Hear Won’t Hurt You June 2010

Analysis of How Noise Impacts are Considered in the Determination of Wind Farm Planning Applications Hayes McKenzie Partnership, June 2011

Wind myths: Turbines can damage your health February 2012

Hansard – Written Answers (Wind Power), 27th March 2012

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Just occasionally paediatric audiologists, particularly those who work in cochlear implant programmes, will meet a child who has been born without cochlea or auditory nerves, or other abnormality of the inner ear that makes a hearing aid or cochlear implant useless. This diagnosis has just been given to the parents of a 4 month old boy and other parents in the same situation have shared their experiences on the NDCS Parent Place forum. This must be devastating for parents who have held out hope for a technological miracle that will help their little one access hearing and speech. Some parents have been researching the option of an auditory brainstem implant (ABI).

An ABI works in a similar way to a cochlear implant and in fact the external parts look just like a cochlear implant. But instead of electrodes inserted into the cochlea, the electrodes stimulate the auditory brainstem directly, bypassing the ear and auditory nerve. This makes the procedure more invasive than that for a cochlear implant.

ABI’s are used most often for adults who have suffered trauma to their hearing nerve which means that it is no longer useful and Manchester Cochlear Implant Programme have implanted more than 50 adolescents and adults in this group. Trauma usually occurs during surgery to remove a tumour from the hearing nerve. Once the hearing nerve has been damaged in this way the person would not benefit from hearing aids or a cochlear implant because the sounds could not transfer from the ear to the brain along the nerve. ABI has only been used for adults who have previously had hearing and use speech to communicate. Where a cochlear implant stimulates different points corresponding to different frequencies along the cochlea, the brainstem does not have this separation of frequencies so the ABI cannot separately stimulate different groups of nerves corresponding to distinct frequency ranges. The ABI therefore provides a sensation of hearing that can help aid lip-reading and provide other clues used in spoken communication (for example rhythm and speed of speech) but these adults are unable to use the ABI alone to hear speech without the additional help of lip-reading etc.

Although ABI’s have been available in the UK for the last decade only a handful of children have had the procedure here. The outcomes for children are more variable than for children who use a cochlear implant – they may only offer access to louder and environmental sounds although some are accessing speech. Like cochlear implants the emerging evidence is that the earlier implantation takes place, the better the outcomes for the child. ABI’s have been used in cases when there is no cochlea (and therefore nothing to implant with a cochlear implant), when the cochlea has suffered extensive damage (such as following meningitis) and an electrode can’t be inserted into the cochlea, and when there is no auditory nerve.

It is understandable that most hearing parents opt for cochlear implants for their deaf child – opening up options for their child to develop spoken language as well as BSL and potentially other languages too. For parents of children in the ABI candidature group it appears that most have instead been opting to concentrate on developing British Sign Language as their child’s first language without technological intervention but there is increasing interest in the option of an ABI.

Further information on auditory brainstem implants including further reading links and research go to the NDCS webpage.

Updates and family stories

Hope for Hearing is a trust that was set up to raise funds for 22 month old Evie’s ABI which was implanted in Italy in June 2012. You can read more about her story and her family’s experiences of the assessment and surgery etc.

amazing amelia had her ABI at 2 years 8 months. Read her blog and watch videos of her progress.

The Fight for Finn is a trust that was set up to raise funds for 18 month old Finn’s ABI which was implanted in Italy in July 2012. You can read more about his story and his family’s experiences of the assessment and surgery etc.

Read Oliver Bosche’s story on the MailOnline on watch him on STV “Deaf toddler hears for the first time after pioneering treatment” in April 2013

Read Danny Pickards story on the MailOnline from February 2014 and his website Help me Hear

Can I recycle my old hearing aids?

You certainly can! There are lots of wonderful projects happening around the world that would love to repair, refurbish and send overseas your old hearing aids for reuse in a developing country. If you do have any old hearing aids in drawers at home do speak to your audiologist first. If you have old NHS hearing aids your audiologist may need to take them back if they are no longer needed (NHS hearing aids are not the property of the wearer – they remain the property of the NHS and are technically on loan to you!) However, if the NHS doesn’t want them back then they may already be a collection point for old hearing aids. If they don’t take back old hearing aids then you can pop them into a collecting bin at your local GP surgery if they have one, or in one in a high street shop, such as a hearing aid dispenser (for example Specsavers Hearcare collect old hearing aids for Sound Seekers) and charity shops (for example Help the Aged or Age Concern). If you can’t find somewhere nearby then you can post you old hearing aids to Help the Aged’s Hearing Aid Appeal or The Hearing Care Centre in Suffolk who will donate them to Lions International.

And what about old audiology equipment?

I get asked this quite a lot, so I keep a list of charities and organisations that carry out humanitarian ENT and audiology work around the world. You’ll find the list here and I’m sure one of them will be delighted to make use of it!

Finally, an appeal for textbooks

This appeal was made in Feb 2012 via the BAA Facebook Group for second-hand textbooks:

“If you know anyone who could help with a donation of second-hand specialist textbooks could you kindly ask them if they’d be willing to give us a helping hand… anybody in the department or perhaps a doctor in ENT?

We are in need of textbooks on any relevant subject… otology, audiology, otorhinolaryngology, general anatomy and physiology, pathology, human biology, embryology, genetics, microbiology, general medicine, pharmacology, acoustics, hearing aids, speech pathology, speech and language therapy, etc., etc, etc.)

Even if it’s just a single book… every book helps… to build a library!

The address in the UK for sending them is as follows:

All Ears Cambodia
21 St. George’s Drive
Brinsworth
South Yorkshire
S60 5NG

Yours

Glyn Vaughan
Director
All Ears Cambodia
info@allearscambodia.org
http://www.allearscambodia.org”

 

And if you know of any other humanitarian projects that I should add to the list please let me know!


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