WHEN SOUND BECOMES PAIN

Acoustic shock disorder and how we hear

“The ear is like an open wound, ” says audiologist Myriam Westcott. Even while we sleep, sound pours through in an undifferentiated flow, which we rely on the brain to filter. That’s often the problem.

It began not with a sound but with pressure. A great pulse or force that pushed him backwards away from the oven and into the kitchen bench. All around him he could see flying fragments “like little mini jets or something whirling past my ears”. It was about 7.30 in the evening, the pub restaurant was buzzing, the ovens and grill plates “full blast”. Later, he would learn that the tiny projectiles were pieces of shredded tin from two commercial spray cans of oil that had fallen behind the stove and exploded in the heat. He would realise that the noise had been loud enough to stop patrons mid mouthful, to bring staff running in from the dining room and his manager down from her upstairs office. But for now there was only shock. Fleeting questions. Had a plane hit the restaurant? Had he been shot? “It all happened so quickly, of course. But the feeling – you can never forget.” Then his boss looming, her face close to his, her mouth moving but nothing coming out, no words, no sounds. And still the enormous pressure, now pushing against his ears, as if he were underwater. And a terrible inexplicable shrieking that he finally realised was coming from inside his own head.

Luke* is sitting at the table in his Melbourne lounge room. Outside in the courtyard garden a water feature burbles ceaselessly. Inside the television mumbles in the background, as it always does during waking hours. Luke has an open impish face, blue eyes and brownishgold hair that corkscrews into wayward spikes. He says he was a “prima donna chef” back in the day: provocative, a perfectionist, sometimes a tease, sometimes a tyrant, but above all fast. He had taught himself to cook for the family by the age of six – “My mother was a terrible cook!” – and worked in kitchens around Melbourne – some well known, others not. For a while he ran his own. Eventually he sold up and got a job in a hotel. Easy work, he thought. No stress. In the kitchen, he likened himself to an air-traffic controller, always in command. Others likened him to Gordon Ramsay. He didn’t care. There wasn’t time. He thrived on it. Then, on that day in 2007, it all stopped. Somewhere in the chaos of the explosion, Luke got himself outside. He turned off the gas at the mains, and then sat down and put his head in his hands. People were talking at him. What happened? Was he okay?

He kept bursting into tears. Even the sound of his own car door closing was unbearable.

Eventually he picked himself up and drove home. All the way there, he could hear that shrieking sound. “I remember thinking I just could not live with this. I just remember thinking that singular thought, how awful it was. But I was still hoping at the same time it was going to abate.” The next morning, the fright had lessened and so had the pressure in his ears. But the noise was still there. In one sense, Luke was fortunate. Not so far from where he lived was the office of audiologist Myriam Westcott. (If you’ve ever had a hearing test or your ears cleaned or had hearing aids fitted, it was probably with an audiologist – though they do a lot more besides.) In the medical hierarchy of hearing, audiologists, known as allied health professionals, generally sit a rung or several beneath specialist ear doctors. But these days Westcott is quite possibly the world expert on an obscure, underreported but sometimes debilitating disorder that, she concedes, may or may not exist. She is convinced it does. Her opinion sometimes puts her at odds with ear specialists and workers’ compensation bodies. If she is right (and there is emerging evidence that she just might be), her findings may have broader implications for the 30 per cent of the population who will experience a more common condition called tinnitus, and could shed new light on the hidden world of hearing, and the ways in which it tries to protect us from threat. Most of all, Westcott’s findings might help people like Luke.

Now let’s get inside your head.

“We’ll start with the simple things.” This is Michael Dobson, a specialist ear, nose and throat doctor (or otolaryngologist) with a particular interest in the strange things that can happen to our hearing. A thin, fine-featured man, he discusses the ear in the same delighted cadence that David Attenborough might apply to an obscure species of shellfish. In fact, Dobson is holding a small plastic model of something that looks a bit like a mollusc. Snaking up its exterior are coloured lines that indicate blood vessels. Now he opens it up, clam-like, to reveal a 3D replication of what lies to each side of our head just beyond the fleshy protuberances we call ears. Over the next half-hour we journey up the ear canal, where sound enters first as pressure waves in the air that waft (or crash) against the eardrum. Then into the engine room of the middle ear with its tiny ossicles – malleus (hammer), incus (anvil), stapes (stirrup) – that operate as a bony piston to amplify the vibration and send it on through an oval opening into the watery coils of the inner ear. Here in the spiral-shaped cochlea, the vibration, now waterborne, washes through palisades of hair cells and is transformed first into chemical signals and then into electrical impulses that zap up the auditory nerve and into the brain. Which is where things get less simple. The first thing to know is that, unlike every other sense organ, the ear has no mechanism to screen out unwanted input. We can blink and spit and snatch our hand from a flame. But we can’t stop sound coming in. “The ear is like an open wound,” Myriam Westcott has said. Even while we sleep, sound pours through in an undifferentiated flow. Think about it: kettles, cattle, birdsong, screams, your neighbour’s dog, that banging door, your lover on the phone, child in the bath, the click and shunt of your own swallowing and breath. Every moment of every day. Which is strange, because that’s not at all how it seems. In fact, the last time you were aware of such a cacophony may have been as an infant (which might explain the crying). Or more recently, for many of us, when you had hearing aids fitted. (We’ll get to that.)

The reality is that we simply don’t register most of the sounds around us. Our ears process them (and even add a few of their own), and send them up into the brain. But what you end up hearing is, well, whatever you were hearing a few moments ago, before you started thinking about what you were hearing. In the absence of a shutter to block out noise, it falls to the brain to do the job of filtering. The brain learns what matters and what doesn’t. Even in infancy we will turn our heads to follow our mother’s or father’s voice. To start with, most of the sounds out there are not relevant. (I don’t need to know that the traffic is still rumbling down the main road near my house.) And even if they are, we can only focus on one sound at a time. Which means the job of the auditory cortex (tucked just above the ears) is to triage the information as it comes in. Sounds that we judge as important (lover, child) are highlighted and go to the part of the brain where we consciously notice them; unimportant sounds sit there, fully heard, half noticed. We don’t consciously decide which noises to hear and which to ignore. All of this happens subconsciously and involuntarily. Hearing is a pragmatic and generally effective system, but sometimes it breaks down. Auditory information gets relayed to brain centres for memory, communication and emotion – people have written books on the effects of music on our brains and bodies. But our ears, like all our senses, have also evolved to protect us from harm by alerting us to potential threats (a rustle in the grass, the creak of a floorboard). In hearing, the same system that so effectively mutes some sounds can amplify and distort others. The more potentially disturbing or frightening the sound, the more our brain focuses on it. Which is where things get complicated. Back at work a couple of days after the explosion, Luke started noticing other things. Every time someone banged a pot, dropped a ladle or slammed a door,

he jumped. These noises had been the soundtrack of his working life; now they were overwhelming. “Every time I heard a loud sound – I mean, it wasn’t even necessarily loud – I’d be panicking. I’d be back at the explosion.” Almost worse, he was floundering. Orders would come in and, instead of memorising every item, he was lost. “All of a sudden I was like all of those other people that I laughed at.” He saw a doctor who told him to take a week off. But when he got back nothing had changed. He was confused, ineffective. He kept bursting into tears. Even the sound of his own car door closing was unbearable. And, still, that high-pitched ringing. Impossible to ignore or drown out. An electrical whine. The louder the surrounding noise, the louder the whine. “The ringing is as comfortable as hearing half a dozen students dragging their nails down a chalkboard, but with the volume turned up from one to 30.” Luke went to another doctor, who diagnosed him with tinnitus.

When Michael Dobson was in his 30s, he did something he regrets. He was at home building shelves and used an electric saw to cut up the chipboard. This was 1977 and he was not yet a specialist ear doctor – nor was he using proper ear protection. He shrugs wryly. “I was silly.” These days Dobson lives with a persistent highpitched squeal in his left ear. That squeal is tinnitus. It can sound like buzzing or whistling or clicking. Dobson’s tinnitus sounds like a cicada. Most sufferers learn to live with it (many barely notice they have it), but an estimated 10 to 15 per cent of the population are aware of constant noise. A smaller proportion – maybe 2 per cent – enter a kind of purgatory. Until about 30 years ago, doctors were taught that tinnitus (from the Latin tinnire, to ring) was somehow produced by the inner ear. And that’s how it was treated, mainly by trying to improve blood flow to the region. Then in the early 1990s an American neuroscientist called Pawel Jastreboff proposed a radical model. Rather than focusing on ear damage or pathology as the cause of these phantom sounds, he argued, we should look to the brain itself. Tinnitus – the sort that people notice – could indeed be triggered by damage or degeneration in the cochlea, and the new sound might be the brain’s way of compensating for the loss of sensory information from the ear (a bit like humming to fill the silence in an empty room). Some conditions and surgeries also seem to predispose people to the condition. But the trigger itself is often irrelevant; it’s what the brain does with it that counts. Jastreboff was intrigued by evidence that relatively few of those reporting tinnitus symptoms appeared to be distressed by them, and that their levels of distress had little to do with the intensity of the sound. He concluded that what mattered most was not the noise, but how people reacted to it. He postulated a pattern of links between the parts of the brain that process sound and those that deal with emotions, threat and memory. The more attention we pay, even subconsciously, the stronger the brain pathways become, sparking a cascade of changes in the auditory system. After a while the original signal no longer matters. The system has become self-sustaining. Today’s clinicians broadly accept Jastreboff’s neurophysiological model of tinnitus. Much about the condition, however, remains a mystery. Tinnitus can happen in one ear or both, or seemingly inside the head. It is commonly associated with hearing loss, but some people with perfect hearing still complain of it. Why most people cope and some don’t is also unclear. Anxious, perfectionist personalities might be more vulnerable. The risk might be greater if the sound first appears in response to a frightening situation and represents potential damage or a threat.

Over the years, Dobson has made peace with his condition. “When you walked in here today and we started talking, I was unaware of my tinnitus. Now that we’re talking, my tinnitus has come from my subconscious to my consciousness. It’s not worrying me, because I know it doesn’t represent anything bad. But a lot of people worry about their tinnitus representing something bad.” Dobson knows what aggravates his: fatigue, stress, too much caffeine. (Other recognised triggers include quinine and anti-inflammatories such as aspirin.) These days, he says, he has learnt to use his tinnitus as a sort of biofeedback mechanism. “When it’s roaring, I say, ‘You better back off; you’re doing too much.’”

It turns out that tinnitus is just one of a group of sometimes distressing hearing problems that can happen not only in the ear but also in the brain – sometimes entirely in the brain. Some people have full-blown auditory hallucinations: hearing voices and conversations that exist only inside their heads. Others develop an almost phobic response to particular sounds often made or instigated by others; this condition is called misophonia. The sounds involved may be loud (the neighbour’s dog) or soft (chewing, swallowing, even breathing). Either way they are experienced as intrusive, sometimes unbearable. Myriam Westcott says she sees a few patients with hallucinations, whom she can’t generally help, and one or two a week with misophonia, whom she can.

Sufferers develop a strong aversion to everyday sounds that others tolerate with ease … When you examine the ears they look perfectly healthy.

For most, the symptoms resolved within a few days; for some, they continued indefinitely.

Many years ago when I knew Westcott a little, she was a round-faced, dreadlocked girl with a hyperbolic smile and a deep delightful voice. These days she works from a practice she jointly owns, speaks at conferences here and internationally, gives evidence in court cases, runs workshops, and mentors other clinicians on what to do when hearing goes rogue. In the early 2000s, Westcott’s particular focus had been on another odd set of symptoms. People arrived bewildered, distressed and complaining that some noises – especially if loud, sudden or sustained – were amplified, as if someone had turned up the volume inside their heads, often to the point of pain. This is hyperacusis. In the Venn diagram of hearing dramas, misophonia and hyperacusis have a sizeable overlap. Sufferers of either develop a strong aversion to everyday sounds that others tolerate with ease. Certain sounds become unnaturally prominent, a process that can intensify and spread over time. When you examine the ears they look perfectly healthy. Yet the conditions of misophonia and hyperacusis do differ, in subtle but significant ways. Westcott says what is central is how the patients interpret the sounds, consciously or otherwise. She believes that each condition has its own inner narrative and its own subconscious, involuntary response (though not always in that order). The misophonia story goes something like this: “That noise (husband chewing, dog next door) is intruding into my space and is unbearable.” And the response of sufferers ranges from irritation through to disgust and rage. Those with hyperacusis have a different internal script: “This sound (a dropped plate, a car backfiring) will hurt or damage me.” And the reaction this time is one of fear, even terror. Westcott believes that hyperacusis is a subconscious “threat response” to sound – and it sets the scene for much that follows. Luke has it. When clients come to Westcott with these symptoms, the first thing she does is listen. “I ask them to tell me about the sequence of events, the symptoms they have, and beliefs they have around them.” Then she checks their ears, does an audiogram, assesses for hearing loss, excludes the possibility of tumours. And if she finds nothing untoward, she tells them what she thinks is wrong with them.

In the 1990s, anecdotal reports emerged of a cluster of bizarre and unpleasant afflictions affecting call-centre workers who had been subjected to a loud, unexpected sound through their headsets. The phenomenon was recorded initially in a 1999 Danish paper. But it was in 2000 that an Australian team first identified the condition and named it. That year, at a Melbourne conference, audiologist Janice Milhinch and auditory physiologist Rob Patuzzi presented a paper that they had co-authored with audiologist Janet Doyle. In it they described workers at a large call centre complaining of tinnitus, hyperacusis, balance problems, headaches, numbness or burning of the face, and emptiness or sometimes fullness in the ear. And pain, often acute – like being “electrocuted”, “stabbed” and “punched” in the ear. Milhinch, Patuzzi and Doyle called it “acoustic shock”. For most, the symptoms resolved within a few days; for some, they continued indefinitely. Westcott knew about the study because Milhinch was her boss. When Milhinch retired, she asked Westcott to continue the work. In the original study, the authors had wondered if some of the symptoms – notably the feelings of blockage and pain – might be related to the intense and persistent contraction of a tiny muscle, the tensor tympani, attached to the malleus bone in the middle ear. This little-known startle reflex was first described by Swedish ear specialist Ingmar Klockhoff 30 years before. He called it tonic tensor tympani syndrome (TTTS; “tonic” as in “sustained”). When Westcott started going through her files, she realised that many of the patients she had been treating for tinnitus (40 per cent) and hyperacusis (80 per cent) also showed evidence of TTTS. It looked like a cluster. “The TTTS insight was a light-bulb moment.” In the years since, Westcott has mapped these symptoms extensively, and presented her findings to sometimes sceptical audiences here and overseas. In 2012 she cajoled clinics in New Zealand, Spain and Brazil into joining hers in taking a snapshot of every tinnitus patient on their books, looking for matching patterns. She found them, identifying a persistent cluster of symptoms – triggered by a sudden loud sound, often including tinnitus, always involving hyperacusis and TTTS. She calls this cluster of symptoms “acoustic shock disorder”. (As with post-traumatic stress, the symptoms get elevated to a disorder when they don’t go away.) Acoustic shock disorder can be triggered initially by a wide range of sounds. Here are a few examples from Westcott’s notes: the starter pistol at a school sports event; a threatening voice at close range during an assault; metal hammering on metal; loud machinery; an unexpected blow to the ear or head; glass crashing; a hand dryer in a public toilet. Critically, says Westcott, while the volume of the initial noise is a factor, the common link is that the sounds are unexpected and startling. Another is the presence of TTTS. The prevalence of other symptoms varies. A tangle of physiological and psychological tripwires can be set off by the sorts of noises on Westcott’s list or even by heightened anxiety about other sounds (including tinnitus), which in turn can escalate into hyperacusis, magnifying and entrenching the middle ear’s protective reflex into the chronic, involuntary spasms of TTTS. This is when sound becomes pain.

By the time Luke met Myriam Westcott he thought he was going mad. He had stopped going out, even to the shops. He smoked dope to manage his symptoms. He drank for distraction. He had seen doctor after doctor and come away with the impression that many saw his condition as either manufactured or somehow his own fault. His partner, Paul, was sympathetic but bewildered. Friends had stopped visiting. Painkillers didn’t help. Equally confusing were the other symptoms: “The pressure in my ears, the type of fright I was feeling every time I heard a loud noise.” He spent days in bed, weeping, and thought about suicide. Luke says meeting with Westcott was the first time he ever heard the word “hyperacusis”. “I’m like, oh, what’s that? But when she explained it I just felt like someone had pulled the dagger out of me. I’m not completely healed, but just by virtue of having someone telling me about the condition and how it occurs, I just felt so much relief.” Westcott went on to diagnose Luke with acoustic shock disorder. While he doesn’t get the stabbing pain, she says his symptoms place him clearly within the cluster. Other doctors disagree, however. Luke describes one specialist walking behind him during a consultation and, without warning, striking a tuning fork close to his ear. Luke says he fell to the floor, sobbing. But eventually, after years of to and fro, his employer’s worker compensation insurer paid him a settlement based on his ongoing symptoms. Meanwhile, Westcott says her travels into the world of subconscious hearing have affected all areas of her practice right down to the simple task of fitting hearing aids. “Audiology is a very concrete profession. We’re taught how to do hearing tests. We’re taught how to do hearing aids. And we often underestimate the amount of counselling that goes around that.” The hundreds of thousands of Australians who’ll end up using aids tend to walk into their audiology appointments excited at the prospect of being able to hear again, only to find themselves flooded with sounds they haven’t heard for a long time – some welcome, some not. “This can be why people reject hearing aids, if they’re not prepared for it.” She

By the time Luke met Myriam Westcott he thought he was going mad.

says that those who have earpieces fitted should wear them all the time. It gives our brain a chance to relearn how to tune out the unimportant input. Similarly, this is what people with hyperacusis and TTTS have great difficulty doing. Westcott has been a highly effective proponent for her viewpoint. She is engaging, persistent and sometimes insistent. Google the words “acoustic shock” and there she is. She advocates fiercely on behalf of her patients and has continued the work of her predecessor in raising the profile of the condition internationally. Call centres around Australia and overseas now use noiselimiting devices and warn staff about risks of acoustic shock. Westcott estimates that she has treated at least 150 patients for the condition – as well as others with related ailments – most of whose symptoms eventually abate with appropriate and careful management. She says her approach is slowly gaining acceptance from audiologists and some specialist doctors. But she is angered at the level of distress she sees in clients who have repeatedly been told they are fabricating or exaggerating their conditions. She receives emails most days from patients and clinicians around the world, seeking guidance. “To be frank, even I am a bit surprised by how dogged and determined I’ve become.” So the suggestion that she might be making things not better but worse does not go down well.

Robin Hooper has a quiet, almost halting voice that sometimes trails off before the sentence has entirely finished. On the walls of his small St Kilda Road office are framed certificates: from the University of Melbourne where he graduated in medicine and surgery in 1961, a fellowship from the Royal College of Surgeons of England, and another declaring him a fellow of the American Academy of Otolaryngology from his days living in New York in the early ’70s. “I was a bit of a restless soul for a while.” On the floor beside his desk a black briefcase bulges with papers and articles, including one he wrote in 2014 titled “Acoustic Shock Controversies”. In it he argues that much of what Myriam Westcott thinks about acoustic shock is probably wrong. Hooper believes the focus on acoustic shock since the start of the century has become self-fulfilling, costing millions of dollars and perhaps putting patients’ longerterm recoveries at risk.

How do you test for a condition that is unpredictable and subjective – and that need not involve structural damage to the ear?