[WARNING: Contains very descriptive language and gory pictures! I hope this might be of some help for someone unfortunate enough to suffer the same ordeal.]
Barotrauma – An unfortunate accident
It was a typical flight from one European city to another. As the plane starts its descent I was entertained in conversation with the passenger sat next to me. I recall being aware that I couldn’t equalise one of my ears as the plane was heading towards the ground. I recall this, because it was unusual for me to have problems equalising the pressure difference caused by flying.
Most of us live mainly on the ground, under the pressure of our atmosphere. But, as anyone who has been on a flight, driven up a mountain or done some diving will know, as we move up and down the Earth’s atmosphere, we feel the differences in pressure mainly through our ear drums. The eardrum is a thin membrane of tissue, or skin, which separates the auditory canal, through which sound waves in air travel, and the middle ear(tympanic cavity), a small chamber containing the ossicles and connected to the back of the throat by the eustachian tube.
<diagram of ear> http://www.macroevolution.net/diagram-of-the-ear.html
The dullness, or sometimes pain, we feel as a plane starts plunging towards the ground (planes go up much slower than they come down because you have to burn expensive fuel on the ascent), is due to the pressure increasing outside the eardrum as we move deeper into the bottom of the atmospheric layer (more atmosphere above us, more pressure). Most people automatically equalise this pressure by moving their jaw, swallowing or pressurising their nasal cavity and pinching their nose. This increases the pressure inside the throat and nose cavity and forces the eustachian tube to open allowing the pressure behind the ear drum to equalise to that in front of it.
As the plane I was in kept descending I realised something was wrong because my left ear was not equalising. It wasn’t exactly painful but I could feel something wasn’t right. I kept on trying to equalise even on the ground but nothing was happening. I couldn’t ‘pop’ my ear! At this point I knew that something was wrong but I wasn’t in pain.
Slowly, some pain started to creep in and I felt more and more pressure on the ear. A couple of hours later, as I lay in bed trying to sleep, the pain was excruciating and, short of chopping my head off or puncturing the ear with a pin, I simply couldn’t do anything to ease it off. I drove to A&E to seek for help as this was probably one of the worst pains I had ever felt and I was very worried that my eardrum would just burst open due to the increased pressure. As I walked into A&E I believed what I needed was a controlled perforation of the ear drum to ease the pressure. This is routinely done to young children who often suffer from glue ear, a condition that is caused by mucus in the middle ear which cannot clear through the Eustachian tube which is tiny and often bent in the smaller, developing, bodies.
In a jam packed A&E ward, in such pain that I couldn’t sit down, I kept on pacing up and down the hospital corridors moving my jaw and swallowing in an attempt to ease off the pressure. At some point I started getting some crackles and pops in the ear and I felt the pressure easing off a bit, although I was still in lots of pain and, by this time, a loud buzz (tinnitus) had set in. I realised I wasn’t going to see a specialist (an ENT doctor) as they are not there overnight and all the A&E doctors would do was give me some painkillers and send me home. So I went home, took some painkillers and tried to go to sleep.
The next morning I went back to A&E and an ENT saw me. At this stage they told me that they could see some damage (possibly some blood behind the eardrum). I had suffered a barotrauma, a condition which is common to divers when something goes wrong in a dive and they resurface too quickly without going through the appropriate decompression stages, or, as happened to me, when flying without proper decompression. There was no mention of any damage to the eardrum. The doctor prescribed a course of antibiotics to clear any infection (surprise, surprise!) and told me I couldn’t fly for at least a week, until I could see them again to get an ‘all clear’. I was literally grounded for at least a week.
Weird and Wonderful Noises
During this week, some really interesting things happened. Of course I struggled with symptoms of deafness. Understanding people, particularly in noisy places, was difficult. At one point, as a waiter brought me a tea:
– Here’s your ***** peony tea, sir.
– Black? But I have asked for a white tea!
– Yes Sir, your WHITE peony tea. (giggles from my friends sat next to me).
A true example of black and white confusion!
At other times I could clearly see/hear a mismatch between the true (visual) location of a source and its corresponding auditory position. My localisation cues were all wrong. This gave me a bit of an insight (insound?) of what it is to live with partial hearing loss.
From the day of the accident I started suffering from really loud tinnitus. Mainly at high frequencies and, when it was strongest, I managed to measure its main frequency component by matching a tone on a sine wave generator (on my smartphone! I don’t carry tone generators around!). It was about 5kHz. This changed progressively and receded from the very loud tones within a week or two. At times it was mainly high frequency noise with some prominent components. After a while, a low frequency rumble joined in. That was a bit more annoying. My best description to it was that it felt heavy. This rumble would sometimes stop momentarily and then come back on again.
Perhaps the most remarkable, albeit perturbing, effect, was what I can only describe as a chorus effect on the sound on the left ear. Something very similar to a chorus pedal effect often used in guitar recordings (Pink Floyd is a good example). It was as if there were very short echoes on my left ear, particularly noticeable at mid frequencies, especially from loud screeching voices. It felt like I had a bubble of liquid in the ear and the sound got trapped there and kept reflecting inside the bubble for a bit. I have not been able to understand what might have caused this effect. Was it the transmission of sound through the ossicles? I will probably never know.
One week later, another ENT sent me for a batch of tests to diagnose the state of my hearing and whether I could fly.
They tested my hearing to check whether there was any internal damage which might cause irrecoverable damage. They do this by measuring your hearing acuity (audiograms) in two ways:
These are my audiograms at the end of that week:
You can see that, compared to the right ear (OD), the left ear (OE) is showing severe loss, particularly towards the high frequencies. The line is much lower on the right hand side audiogram. The good news is that the left inner ear seems to be healthy, as the bone conduction levels (the ‘>’ in the graph) are normal, except at the higher frequencies, where the loud tinnitus might be responsible for masking the tones I was supposed to pick out. Tinnitus arises from hyperactivity of the auditory hair-cells responsible for converting vibration into electrical pulses inside the inner ear. Given the trauma to my hearing system, it is not surprising that there was onset of tinnitus.
They also measured the movement of the eardrum (tympanometry), which is often affected if there is build-up of fluid due to infections, inside the middle ear, or if the eardrum has been perforated. They do this by pressurising the auditory canal, from outside, over a range of pressures, whilst driving it with a 220Hz tone and measuring the response of the pressure in the cavity as the ear drum flexes. A healthy eardrum will show a peak in the response (see the ‘sweep right’ in diagram below), whilst a perforated or restricted (by fluid) eardrum will show a flat response (see the ‘sweep left’ in diagram below).
According to these tests, I hadn’t suffered internal ear damage, and the losses appeared recoverable, which was great news. The bad news however, where that there was severe loss of sensitivity on the left ear, and the eardrum appeared to be blocked which meant I shouldn’t fly. In the doctor’s words:
– You can try, but it’s going to be extremely painful.
A trip of 3 days, 3800Km and 4 different trains back to Manchester ensued. I got to see dragons flying across the sky and have croissants in Paris.
On the mend
Back in the UK I went to see my GP who gasped as he looked into my ear:
– You have a perforated eardrum! he said.
– Will it heal?, Do I need surgery?, Am I going to be deaf?, What about the tinnitus. Is it going to go away?
I’m lucky to work in a top centre for Acoustics Research, so we have the right kit to take gory pictures of punctured eardrums. The following picture was taken 2 weeks after the accident and the damage is very visible. The whole eardrum is burst.
With an 18 week wait to see an ENT through the NHS system I booked an appointment with a private doctor. I went in armed with the batch of audiograms, the picture of the punctured eardrum, and another one I took just before going to see the doctor:
After explaining my ordeal, the doctor had a look. He said something like:
– There’s a bit of skin. This is going to be a bit sore, and loud.
He scrapped and hoovered inside the ear canal, removing the necrotic bit of my original eardrum (the red patch on the left side of the picture), which was glued to the top of the new, healthy, ear drum that had since reformed underneath! Apparently, throughout this time, my body had been busy rebuilding a perfectly tuned, new ear drum. This took less than 12 days! I left the hospital ecstatic!
Once the doctor removed the old bits of skin, a full eardrum can be seen underneath.
Causes and Outcomes
So, what might have caused the barotrauma? Most likely I would have been suffering from some mild congestion, and a bit of a cough, which might have blocked the airways and the eustachian tube. Because of this, as the pressure changed from ground level to cruising altitude (10,000 m) the slow variation allowed the pressure inside and outside of the middle ear to equalise. The more abrupt change caused on the way down caused the pressure outside to compress the eardrum and, as I wasn’t aware of the problem, I didn’t attempt any active equalisation procedure (eg: blow through your nose while pinching it, followed by swallowing) until it was too late. By then, the eustachian tube, which might have been slightly blocked from tissue inflammation, was closed shut by the lower pressure inside the middle ear, effectively creating a vacuum. Once that set in, there was no way of reverting the pressure gradient across the eardrum, apart from actually perforating it.
But, as I arrived on land, the pressure on the eardrum wasn’t that high! At that point I was just having a mild discomfort sensation. How did it evolve from that into an excruciating pain?! This is the sinister twist that I found most disturbing. The air that we breathe, which is also found inside the middle ear, behind the eardrum, contains about 78% nitrogen. However, in our blood stream, the concentration of nitrogen is lower at around 40%. This means the mucosal lining inside the middle ear will absorb some of the nitrogen in the air, due to the imbalance. This will cause a drop in pressure within the middle ear, which we equalise throughout the day by swallowing, causing the eustachian tube to open and allowing the external pressure to equalise with that inside the middle ear. If the eustachian tube is blocked and pressed shut because of a large pressure difference, there is no amount of swallowing motion that will make it open. This explains why, only some time after landing did I start to feel the increased pressure across the eardrum causing such strong pain[ http://deedee.dbi.udel.edu/MichaelTeixidoMD/pdfs/OtitisMedia.pdf].
At the end of this ordeal, I am left with a very gentle tinnitus, mainly in the high frequencies. It seems to be receding and I am hoping it will be gone some time soon. A few weeks later I also started getting symptoms of vertigo which, apparently, might be related to this accident and caused by debris in the vestibular canals [https://en.wikipedia.org/wiki/Benign_paroxysmal_positional_vertigo]. This still hasn’t cleared and I’m having to do some exercises[http://www.webmd.com/brain/brandt-daroff-exercise-for-vertigo-16844] to, supposedly, clear the debris.
A final few words of advice if you are going to fly (or dive):
If all this fails, I hope you will feel comforted by the fact that eardrums actually grow back!