How much do you know about how your ears work?
My Amazing Body is a podcast where we explore interesting, unknown and misunderstood parts of your body with help from medical experts and stories from real Queenslanders.
This episode is all about your ears. From Dr Janice Wu PHD, we learn all about how the ears work: how they enable you to hear, how they help you make sense of the world around you, and the role they play in balance. She also talks us through conditions that can affect your hearing and balance, and the things you can do to look after your hearing health. We hear from author Jessica White, who lost 75% of her hearing from a childhood illness, about how being deaf affects her in day-to-day life. Queensland man Dion talks about his experience with labyrinthitis, a condition that affects the balance centres of the ears, and how one day his brain suddenly couldn’t tell up from down.
Meet our guests
Dr Janice Wu PHD is a paediatric diagnostic audiologist.
Jessica White is an author and university lecturer, who speaks and writes about her experiences living as a deaf person in a hearing world.
Dion woke up one morning with labyrinthitis, a condition that affects the balance centres of the brain.
Episode materials
Audio is great, but some things are best seen as well as heard. These materials provide more information about topics we touch on in the show.
Diagram of the ear
In the episode, Dr Wu details the outer and inner parts of the ear. Here you can see how they all fit together.
Jessica’s hearing devices
Jessica talks about the different technologies she uses to hear, including her hearing aid, Roger pen and loop systems. Below you can see pictures of these devices, while above you can see Jessica as a little girl about to head off to preschool, a few months after the meningitis infection that damaged her hearing.
Supporting people with hearing loss
You can find more information about hearing loss and deafness, and supporting people living with hearing loss at the below links:
Royal Institute for Deaf and Blind Children
Transcript
Host: Can you hear this?
What about this?
What about this?
That was 20,000 hertz, the highest frequency humans can hear. Here it is again.
Chances are, you can't hear anything. We're not pulling your leg – the sound is there. But unless you’re a child, your ability to hear it might not be.
Hi, I'm Elise. Welcome to the latest episode of My Amazing Body, where we explore interesting, unknown and misunderstood parts of your body. Today we're learning about the ear. How does hearing work? Why are the ears so important for balance? Why can't you hear a sound at 20,000 hertz, and what can you do to prevent future hearing loss? Listen on to find out.
Babies are born with fully developed hearing. In fact, babies can hear even from inside the womb; pregnant women might notice their baby jump or kick in response to loud noises.
Dr Janice Wu PHD is an audiologist who works at Queensland Children's Hospital. We asked her to explain how the ears work, and how our sense of hearing might change from when we're a baby, as we grow into adults and enter our senior years.
Dr Wu: Hi. My name is Janice Wu and I'm a paediatric diagnostic audiologist. I work at the Queensland Children's Hospital.
In my job as a hospital-based audiologist, I'm involved in the diagnosis of hearing loss.
Host: To do her job, Dr Wu has to have an intimate knowledge of the anatomy of the ear. She says that while it might look simple from the outside, the inner workings of the ear are very complex.
Dr Wu: The ear can be broken into three main parts, the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna, which is the part that we can see on the side of our head as well as the ear canal.
Host: The ear canal is the opening you can see inside your ear. Sounds travel down the ear canal towards a series of mechanisms that allow you to hear.
Dr Wu: At the end of the ear canal is the eardrum and our middle ear consists of the eardrum and three little bones called ossicles, which are joined together like in a little chain, which then connect the middle ear to the inner ear.
The three little middle ear bones, the ossicles are actually the tiniest bones in our body. All three ossicles could fit together on a surface area that's smaller than a five cent piece.
Host: The process of hearing doesn't stop at the middle ear. Deep inside the ear lives an organ called the cochlear, that's vital for turning sounds into hearing.
Dr Wu: The inner ear is where we have our organ of hearing. We have the cochlear, which is the spiral shaped part of the inner ear, which is filled with fluid and rows of tiny little hair cells. When our ear picks up sounds, those sounds, which are in the form of invisible sound waves, those are captured by our outer ear and travel through our ear canal and vibrate our eardrum and those little bones in our middle ear.
Those tiny movements or vibrations are then transferred to the inner ear and they start to move the little hair cells in our inner ear. Those vibrations are transformed into electrical signals or impulses and those then travel through the auditory nerve up to the brain, and our brain then interprets those electrical signals as sounds.
We can't see what's happening on the inside there beyond the eardrum, but those different sound waves that are generated by the vast array of sounds that we're exposed to every day, they will vibrate different parts of our inner ear and so they will create different electrical signals. Our brain will interpret those signals as either high pitched sounds or low pitch sounds, loud or soft sounds.
Host: If you can hear, it's probably something you take for granted. But one in six Australians have some level of hearing loss, from mild hearing loss to profound deafness. One in 1,000 Australian babies are born with significant hearing loss, while others will lose hearing from illness or injury.
We spoke to Queensland author Jessica White, who lost 75% of her hearing after a childhood illness. Jessica grew up on a property in regional New South Wales, and remembers the morning she got sick vividly.
Jessica: I got meningitis when I was nearly four and we were in a really remote part of the country. We were on a property outside of town called Boggabri, which is about an hour's drive from Tamworth. My first memory, which I write about in the book, is of lying on a trampoline with this incredible pain leaking down the back of my neck and everything was incredibly bright.
Host: Jessica's mum knew something was very wrong, so she drove her to the doctor, who immediately sent them to a larger hospital.
Jessica: That was a half hour drive, then she had to drive for another hour to get to Tamworth. They did a lumbar puncture – put a needle in my spine – to check if it was meningitis.
It was, so they got me a massive dose of antibiotics and I had a respiratory arrest and just about died. Then they called the priest in for the last rites. We weren't religious, it was just, that's what they did.
Host: Jessica survived, but her hearing was irreparably damaged. Dr Wu says that illnesses like meningitis pose a high risk for causing hearing loss and can damage hearing mechanisms in a number of ways.
Dr Wu: An infection like meningitis, if it's a bacterial infection, is a high risk for potentially causing hearing loss. It can damage the cochlear hair cells and it can also potentially cause what's called ossification, which is a bit like hardening and calcification of those inner ear structures. So, if anyone has had a meningitis infection, it's very important that they have their hearing checked afterwards, because there is a very high risk of hearing loss.
Host: Because Jessica had already learned to listen and speak, her hearing loss wasn't initially obvious. But it didn't take long for her parents to notice something was quite right.
Jessica: They took me home and it wasn't until a couple of weeks later that they realized something was wrong, because I kept saying pardon all the time. Then mum said that she just shouted at me down the hall way to go and clean my teeth and I didn't twig, I didn't turn around.
So, I've lost all my hearing in my left ear and I've lost about 40% in my right ear, but because the two ears work together, it only works out to be about 50% in this ear. So, I'd say I've got about a quarter of an average person's hearing.
Host: Hearing doesn't just affect how a person responds to sound in the moment, it's also a vital part of spoken language development in children. While Jessica had the basics of speech down pat before her illness, she found that being deaf started to impact her ability to communicate with her peers as she got older.
Jessica: It wasn't until I got to high school that things were really problematic, in terms of growing up. I was incredibly isolated because I couldn't communicate with people.
You learn how to have conversations by overhearing your peers and overhearing conversations and I didn't know how to do that. I didn't have the hearing to do that. Mum and Dad taught me ‘this is how you have a conversation’, and they taught me role playing, basically ask someone about the weather. I was like, you just go to the window you don't need to ask about the weather. It was so boring. It was just small talk was so boring. It wasn't until my twenties that I've worked out that you have to do the small talk before we could actually have a conversation.
Host: Jessica uses a variety of different skills and technologies to communicate with the hearing world. In school, she used an FM radio system that transmitted what her teacher was saying directly into her hearing aid. Now she uses a similar system as a university lecturer, to hear what her students are saying in class. She also uses technology called a loop system to hear at the movies. While these kinds of tools, along with knowing how to lip read, help Jessica, she says operating in a hearing world as a deaf person can be frustrating and very tiring.
Jessica: I use my FM – they've got a new version now called Roger Pen, which looks like a pen and you point it at people – and I use that in my tutorials and I say to the students, put your hand up if you've got to speak. That helps, but my whole body is working to hear these people because I've got to work out what direction they're coming from and I feel myself tense with concentration. After each tutorial I feel like I have run a marathon. The Rodger Pen is amazing, I wouldn't be doing my job without that. I've got a new hearing aid, which is also quite incredible.
The technology is amazing and when it works, it's amazing, but often it doesn't as well. If you go to cinemas, the loop systems are often broken, they're getting better.
Once I went to a cinema and it had been broken for months. I complained, I said this is discrimination and the Kid gave me a free ticket, my God, I can't hear a movie, why would he give me free tickets. Eventually I complained and I said this is discrimination and the manager wrote back and said, don't be ridiculous, of course there's no discrimination. And I said, I can understand in a one-off situation it might not seem like discrimination but when it happens to you repeatedly it is. He gave me some more fresh tickets so I am like (laughs)... They eventually got a better system but I didn't go back there for a long time because I was so insulted. When they work they're incredible, when they don't work, it's frustrating.
Host: Jessica encourages people to be more mindful of those with disabilities like deafness or hearing loss, especially because it's not always easy to tell that a person has a disability just by looking at them, or in her case, hearing them.
Jessica: I have to work hard to convince people in the sense that I will have a conversation with someone. I'd say, I can't hear very well, can you please speak clearly? They do for two minutes and then they forget.
I'm exhausted all the time. I say to people, I've only got 25% of the average person's hearing but they can't conceptualize that because I don't sound like I have a speech impediment even though there is a bit of a lisp sometimes. It's a double-edged sword.
Host: While the meningitis damaged her hearing, Jessica has found her other senses have developed to compensate.
Jessica: I notice a lot of things happening in my peripheral vision, which I think they've done research to support. You’ve got to watch out for being run over by a car!
Host: She also says her sense of smell helps understand what's going on around her.
Jessica: I'm just sitting on a bus and I'm reading, I can work out where the people are and who they are by what they smell like. Whether it’s their perfume or they haven't washed or they have been playing sport and things like that. It's very acute.
Host: Jessica is the author of two novels, with a third book, Hearing Maud, about deafness, coming out this year. If you'd like to learn more about services for people who are deaf or have hearing loss, and how you can support them, we've included some links to useful organisations and resources in the show notes for this episode.
Are you ready for this episode's mystery body part? See if you can guess what the body part is from the clues given. We'll reveal the answer at the end of the episode.
What am I? You have four sets of me, two upper and two lower sets. On average, I'm 10 millimetres long, though the record is 6.99 centimetres. People have been styling me since 4000 BC. I act as a dust catcher for your eyes, removing dirt and debris with the help of tiny mites called demodex. Do you know what I am?
Your ears allow you to hear, but that's not all they do. They also play an integral role in helping you balance, sending signals to your brain that tell it how your body is positioned at any given moment. Dr Wu explains how it works.
Dr Wu: Our ears are not just necessary for hearing, they're also really important for balance. Our eyes, our inner ear and our muscles and joints all work together to give our brain information about where our head and body are in space. That allows us to then be able to compensation for our balance.
In our inner ear, we don't just have the organ of hearing. There are also three loops called semicircular canals. Inside the semicircular canals are tiny hair cells and fluid. When our head and our body moves, the fluid and the hair cells in those semicircular canals also move.
One of the canals senses up and down movements. The second canal senses side-to-side movements and the third canal senses tilting movements.
Host: Your ears also help you situate yourself in space…
…letting you know if you're hearing something on your left…
…or if you're hearing something to your right.
It's possible for illnesses that affect hearing, like an ear infection, to also affect a person's sense of balance. Queensland man Dion found this out when, after having a-run-of-the-mill cold, he woke up one day feeling very peculiar.
Dion: I went to bed feeling like I had a cold or a flu and woke up the next morning to a really odd sensation like you've been spinning around and around and around for about a minute. And the room just kept spinning and spinning and spinning while I was lying in bed, and it didn't stop spinning. So that was quite terrifying to wake up and not know which way is up and which way is down.
Host: Dion had labyrinthitis, a condition where the inner ear, or labyrinth, becomes inflamed, often as the result of a bacterial or viral infection. After lying in bed and realising that the spinning wasn't going to stop, he figured he had to go to a doctor to find out what was going on. But getting out of bed without a working sense of balance was a whole new challenge.
Dion: Well, the first thing was getting out of bed, and that was a challenge in itself. So, I was literally holding on to the walls as I was walking around my room, or walking down the corridor. I lived with my brother at the time, so I got him to take me to the closest GP that we could find.
Host: With the world spinning and his stomach spinning with it, Dion spent the next few days on the couch trying to hold down food with the help of anti-nausea medication.
Dion: So, the nausea was such that I was wanting to vomit pretty much all the time, and the only way that I didn't was by lying down on my side and watching TV. And so, I basically ate and drank as much as I could on my side for those first couple of days, so that I didn't feel overcome with nausea.
Host: While his condition gradually improved, it took a while longer for him to get a diagnosis. After running tests to make sure there was nothing going on neurologically, Dion was sent to a balance specialist.
Dion: Once the initial really strong symptoms had gone past, it was to the point where I was able to function day-to-day. However, my energy levels were about half of what I would like them to be. And my eyes got really, really tired. Because I gather that they were giving me the most accurate information as to what was up and what was down, because my balance was off. So, I found myself with really, really tired eyes.
The diagnosis actually came about five months later. So, after a number of GP visits and a number of tests I was eventually referred to a clinic that specialized in hearing and balance.
So, when I went to the specialist clinic they did some tests on me as part of their attempt to diagnose what was going on with my balance. And they did some tests with my eyes, so following a dot around a screen, sort of tracking my movement. They also did some tests specifically with my ears. And the one that made me feel the most nauseous, which I've never experienced before, was they had basically a tube that pumped air, a small amount of air, and I would lie on one side and they would put that tube into one ear. And they did it first with cool air, and they sort of pumped cool air into my ear for about two minutes, and made me say a rating of 1 to 10, how nauseous it made me feel. And after about 30 seconds it just makes you feel incredibly nauseous, to have this air pumped into your ear. And it's the strangest feeling.
Host: Some people with labyrinthitis have a more mild experience of the condition and don't require treatment. But for people like Dion who don't fully improve, therapy is required to help their brain recalibrate to the new signals coming from the balance centres in their ears.
Dion: So, by the time I got my diagnosis I'd been back at work for a few months. I'd been working in a retail environment so I was doing lots of bending over, putting stock on shelves, talking to customers, you know making my way to work each day. And that was actually the best form of recovery. So, the recovery is designed around recalibrating your internal balance receptors, and to do that you do lots of mobility exercises, walking backwards, bending over, bending over sideways, trying to balance with your eyes closed, which is now something I'm really good at. With the idea that the brain or the messages will recalibrate your sense of balance. I just have a newly calibrated balance between my two ears.
Host: The ears impact your overall wellbeing in so many ways. So how can Queenslanders look after their ears and their hearing health? We asked Dr Wu to give us the lowdown on everything from loud noises to cleaning your ears.
Dr Wu: The most important thing is to preserve the hearing that you have. We would always encourage people to be mindful of loud noises or excessively loud noises that they're exposed to, because hearing damage from noise exposure can occur at any age and, unfortunately, it's generally irreversible.
Once we damage those little hair cells in our inner ear, they don't regenerate. Hearing protection and hearing preservation is important from an early age and all through life. Some of the things that people can do are to ensure that they're just turning the volume down if they're using personal listening devices, limiting the time that they're exposing themselves to loud noises, whether that is in the workplace or in their own homes or through leisure or recreational activities to wear appropriate hearing protection when you're exposed to loud noises.
Host: The louder a noise is, the more quickly it can damage your hearing. We measure how loud a sound is in decibels.
Dr Wu: Anything that is sort of normal conversation is 60 to 65 decibels. I talk a bit louder, so I could be 65-70. 85 decibels is loud, and that's probably anything above that is where it can really start to get damaging.
85 decibels depending on the sound is damaging, but it probably takes a little bit longer for the damage to take effect. The loud it is, it just means that it is less time that it's safe. If it was like at 110, you could be doing damage after 10 minutes or five minutes. If it's 85 decibels, you might be able to listen to it for like six hours and you might get a little bit of damage.
Host: According to Know Your Noise, a rock concert clocks in at about 103 decibels, which will damage your hearing after 7 and a half minutes. Do you listen to a personal music player, like your smart phone, on full volume? That's 106 decibels, and you've got just under 4 minutes before your hearing could be impacted. Dr Wu says because we live in and work in environments that often get very noisy, it can be easy to overlook the potential for hearing damage.
Dr Wu: If the damage is very gradual, sometimes people go, ‘Oh, I don't find that loud anymore,’ or they keep turning up and they think they're getting used to it and I can just crank it up. I think that's actually a sign that you already have damaged your hearing so that you don't realize that you're turning it up louder and louder.
Host: Have you ever noticed a ringing in your ears? Tinnitus affects one in 10 Australian's and can be a sign that your hearing has been damaged.
Dr Wu: Tinnitus is a condition where some people hear buzzing or ringing sounds in their ears. Tinnitus can be a sign that you have damaged your hearing. Often, patients report a ringing or buzzing sound or a dullness to their hearing after they've been exposed to loud noise. Quite often, that tinnitus can be a sign that you have done damage to your hearing.
Host: Like eyesight, it's common that people's hearing will deteriorate as they age, with higher frequencies often the first to drop off. Remember when we played 20,000 hertz at the start of the episode? Dr Wu explains that there's a biological reason you might not be able to hear these high-frequency sounds.
Dr Wu: A hearing loss that's age-related, people typically start to lose those higher frequencies first. That's because the way the cells are laid out is that the area of the cochlear that responds or reacts to high-pitch sounds is at the start. It's like all sounds go through it first, even if it's a deep sound to then stimulate the part deeper in. It's that initial part or start of the cochlear. It's just more that wear and tear.
With the cochlear, because it's that spiral shape, those tiny hearing cells or hair cells, they're just little rows of hair cells. As the sound waves travel in, depending on the frequency of the sound – all of the hair cells don't vibrate all the time – they vibrate different parts of the cochlear depending on the frequency of the sound. The way we explain it is like if you were to kind of unroll the cochlear and it was flat, you could imagine like a piano keyboard sort of thing where you'd have the lower section. Like the lowest tones and then the higher tones.
High frequencies are really important for us to get the definition of speech. It's being able to detect the differences in vowel and consonant sounds. When you lose that, then it does sound like everyone is mumbling.
Host: Wearing earplugs or earmuffs is one of the best ways to protect your hearing from loud noises and help those high frequency hair cells healthy for as long as possible. On that note, Dr Wu says that earplugs are the only things that should be put in your ears.
Dr Wu: Anything other than earplugs or anything that's specially made for the ear, anything other than that, we wouldn't be recommending that people are putting into their ears. There is the risk that you could damage your ear canal or your dreams, so you don't want to potentially poke a hole in your eardrum and create any damage like that.
Host: And while you might be tempted to poke around in your ear to clean out earwax, it's unnecessary to remove it, and can cause a lot more harm than good if you're shoving a cotton bud down there.
Dr Wu: Earwax is just a normal part of the ear. It's naturally antibacterial. We don't generally recommend that you get in there with, say, a cotton bud and clean the earwax out. Earwax over time just naturally makes its way out from further inside the ear to the outside of the ear.
If you can see some excessive wax on the outside of your ear, or just on the outer part of the opening of the ear canal, then you can certainly just clean that away with a damp towel or something like that. We don't generally recommend that you use cotton buds, as you might get a little bit of the wax out but quite often you also likely to push some of that wax back inside. That can potentially build up and harden and create a problem.
Host: If you've noticed a change in your hearing, like tinnitus, finding it hard to hear people, or noticing you're turning the volume on your TV or music player up more than usual, it's important to see your GP or hearing specialist to get it checked out and prevent further damage.
Dr Wu says that as an audiologist, helping people minimise the impact hearing loss can have on their lives is a highly rewarding part of her job.
Dr Wu: I'm really interested in sound and how we experience sound. I actually have a background in music and music education. That is what initially attracted me to audiology, but what I really like about my job is that I feel like I'm making a difference in people's lives. Because it's not visible - the impact that hearing loss can have on their lives can be quite debilitating. It can be very socially isolating. In the case of an infant or child, it can have significant impact on their speech and language development and social development.
Host: One part of Dr Wu's job is working with children and babies with hearing loss, who will be fitted with hearing aids or cochlear implants. Chances are you've seen a heart-warming video of a baby having their hearing technology turned on and hearing their parent's voice for the first time, like this audio of baby Harrison, diagnosed at birth with bilateral moderate sensorineural hearing loss, having his hearing aids switched on for the first time when he was just six-weeks-old.
Audio of baby gurgling, parents: “Is that a smile? Can you hear that? You like it, hey?”
Host: But Dr Wu says that not all babies have a positive reaction to their devices being switched on, and that parents shouldn't be put off if instead of smiles, they get a few tears as their child adjusts to the world with sound.
Dr Wu: Particularly for a cochlear implant, for a child who has been born deaf. If they've been born deaf, they have minimal or no hearing. For them to suddenly have this thing turned on and for them to be receiving something that is a sensation of sound is actually, I think, likely to be quite frightening for them, because it would be completely foreign.
Typically, what we get is we turn it on, we activate it through the computer software and then there's a slight pause as we wait for it to be activated. Then we typically see the child start screaming or burst into tears and then we turn it off immediately. We always warn the parents that it could be any kind of reaction, but just expect possible screaming and tears.
Host: Whether there are tears or smiles, Dr Wu finds satisfaction in her job identifying hearing loss and helping children and their families get appropriate medical care and support.
Dr Wu: I like to feel that I'm making a difference in people's lives, identifying that hearing loss as soon as possible and making sure that we refer them on so that they get the appropriate support and rehabilitation that they need so that they can reconnect socially and that their development is not impacted. We can minimize the impact on their lives that the hearing loss might have.
Host: Thanks for joining us for another episode of My Amazing Body. Before we go, did you guess our mystery body part for this episode? The four sets of dust catchers for your eyes are your eyelashes!
My Amazing Body is bought to you by Queensland Health. With special thanks to our expert guest Dr Janice Wu, our guests Jessica White and Dion Read, and mum Eisha-Marie who provided audio of her little Harry hearing for the first time. Thanks to my podcast colleagues - Lauren our researcher, writer and producer, Carol our audio technician, Helen sound effects, Dan our Music Guru and the media team at Children’s Health Queensland.