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…
Anyone know of any research or evidence of negative impact of wind turbines on hearing aid / cochlear implant wearers or devices? #AudPeeps
— Vicki Kirwin (@KidsAudiologist) May 2, 2012
… 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
