Regular lifelong surfers may find themselves going deaf. This post is about how I found out that some of them are 17 times more likely to go deaf than others. It is due to the effect of the wind and sea cooling the external ear and mastoid bone. This leads to the formation of cranial exostoses; surfer's ear. Most surfers know they should wear ear plugs but many aren't aware that they also need to wear a surfing cap. This keeps the mastoids (the bony lumps behind your ears) warm so they can defend themselves. Most surfers who have been surfing for ten years or more without protection will show varying degrees of the condition. Little research has been carried out in this area.
I decided to carry out some new research to try and find out how many surfers are affected. I also wanted to know what effect wearing ear plugs and a surfing hat makes. It has been shown in studies that wearing both does reduce the risk of surfer's ear but nobody knows by how much. I also wanted to know how much time people were spending in the water before developing the condition. I decided to do some research.
I live in Cornwall, UK, and work in a hospital where a large number of the employees are avid surfers. I emailed colleagues and encouraged people to share the survey with their friends, finally ending up with 203 respondents. This is a good number to make sure any results would be true and not affected by using a small group. This is the first time anyone has shown how much a surfer's risk of surfer's ear is reduced when they wear a hat and surfing ear plugs. Our plugs are ideal at preventing the condition and are available from http://zenplugs.com/surfing-earplugs/
Amazingly, as you will see in the infographic, 60% of surfer's who had been surfing for more than 10 years knew that they had surfer's ear. The actual percentage within the group with surfer's ear is sure to be much higher than this. Some individuals would not know they had the condition unless they were either going deaf or had their ears examined.
Most of the respondents live in Cornwall and surf in cold water. This region is world-famous for it's surf which may be why there are so many long-term surfers who surf very regularly. The infographic has details on this. It is likely that people surfing in warmer waters such as the Caribbean are less prone to the condition. It still occurs due the evaporative cooling effect of the wind on wet ears.
Some Surprising Results
According to the survey results people who wear a hat and ear plugs are 17 times less likely to develop the problem than people who don't. I have explained where this figure comes from at the bottom of the page under 'The Geeky Bit About Stats'. The people who wore ear plugs and cap more than 90% of the time didn't get surfer's ear at all. Most people who didn't wear them developed the problem at some point. The longer people surf for, the more likely they are to develop the condition. This appears to be common sense but isn't necessarily the case. Interestingly there is a small group who never got the condition. This was despite not taking precautions and surfing regularly. Presumably these people weren't susceptible. I have come across no reason for this whilst researching the condition. It is possible that anatomical variation may contribute. Having narrow, hairy ear canals would trap air in airlocks and keep the canals warm and dry. This may be a factor but I have found no evidence to support this.
According to the British Surfing Association (BSA) 500,000 people in the UK surf on a regular basis. This means that this survey has statistical significance at the 6% level. This means that the results of the survey are true to within 6% across all the surfers in the UK.
The research has generated many other fascinated insights into surfer's ear. I will post links here when the posts are live. I have summarised the results so far in the infographic below for your perusal. Please click to make it full size.
If you would like to embed the infographic on your page you can use the following embed code. Please could you attribute it to us at http://zenplugs.com.
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What Causes Surfer's Ear?
Exposure to the cold water and wind causes the ear to grow bony lumps around the opening. These are called 'cranial exostoses'. The ear canal gradually closes over and when it reaches about 90% narrowed the surfer experiences deafness. Studies have shown that the thin membrane covering the bone (periostium) causes the formation of the new bone.
You may be wondering why the cap is necessary. If you put your hand behind your ear you will feel a bony lump. This is part of the skull called the mastoid which is bone full of air spaces which help drain the middle ear. As these are an extension of the ear they are affected in the same way by the cold. A surfing cap keeps them warm.
There is poor awareness within the medical profession and amongst surfers. Doctors working in regions where surfing is unusual may know little about how to prevent the condition.
An early sign is waterlogging. The narrow opening prevents drainage and evaporation from the ear canal. Ear infections are more common as a result of this, as well as due to the accumulation of debris in the canal. Dead skin, wax and dirt build up. When it becomes wet it is an ideal breeding ground for fungi and bacteria. The survey also asked questions about the incidence of infection in those with the condition; more to come on this in a future post.
Surfing Ear Plugs
A good pair of surfing earplugs worn with a surf cap prevents the condition. ZenPlugs Molded Earplugs are ideal because they are also antibacterial and can be joined via a cord to avoid loss. As they are individually molded to your ears they are great at keeping water out. They last for years and are available in bright colours which contrast with the sand so you can find them if you drop them.
Why Do Surfers Go Deaf?
Over the course of years of surfing the body grows bony lumps in the ear canals because of the cold. This gradually closes them over, leading to deafness and ear infections. The problem affects the majority of surfers who have surfed more than 10 years without taking precautions. New research shows that 60% of surfers of more than 10 years know they have surfer's ear.
Is It More Likely In Some People?
Yes. The research has shown that the problem is more likely the more time you spend in the water. It has also shown that the problem is totally prevented by wearing ear plugs and a surfing cap. They are so effective that nobody in the survey who wore a hat and ear plugs more than 90% of the time developed the problem. It also showed that you are 17 times more likely to get the disorder if you don't wear them. This is the first time research has demonstrated this fact.
What Does That Graph Mean?
The graph means that the more often you wear your hat and plugs, the longer you go without surfer's ear. The numbers along the bottom are the percentage of time people wear cap and plugs and the numbers up the side are the number of years of surfing. If you wear them 40% of the time, you will get to about 11 years without developing the problem. If you wear them 80% of the time you will get to about 16 years.
Tell Me More About The Research
203 surfers completed the survey which was conducted independently by Dr Toby Bateson for ZenPlugs. They averaged 2 hours per session, 8 surfs a month and 15 years of surfing giving an average time in the water of 2880 hours. For more information please read the full article at
Why Are Some Surfer's 17 Times More Likely To Go Deaf?
The Geeky Bit About Stats
I've put this bit at the end to save most people the trouble of skipping over it. For those of you who are interested, this is how the relative risk was calculated.
RR = Probability of event when exposed/Probability of event when not exposed
The following table shows the relevant numbers.
The calculation is as follows;
RR = (0/(0/4))/(37/(37+124))
As you may well know, dividing a number by zero is not possible so it is acceptable in this situation to substitute zero for 0.5. This gives;
RR = (0.5/(0.5/4))/(37/(37+124))
RR = 4/0.23 = 17.4
As far as I can see, this is the first time anyone has calculated this risk reduction.
Thanks for reading, please leave your comments below.
Dr Toby Bateson
MB ChB, College of Emergency Medicine Certificate Of Training In Good Clinical Practice In Research