Music induced hearing loss
Losing hearing to an art devoted to sound creation may sound ironic, but it does happen. Here we tease apart the process, helping you identify signs of injury so you can be aware and take action.
Music Induced Hearing Loss
Our ears are like any other part of our body, with overexertion they get tired. If worked beyond their comfort zone, this fatigue can result in something known as music induced hearing loss (MIHL). There are two main types of MIHL; acute and chronic. Acute denotes hearing injury that results from an incredibly loud, impact sound (>130 dB SPL), causing instant trauma to the ear (fortunately, this is very rare in the musical realm). The other type, chronic, is much more common however, resulting from many repeated smaller injuries that stack on top of one another over time. This form can come on so slowly it is often called insidious, as it sneaks up over several years before an individual may realise what’s gone wrong. Unfortunately, hearing loss of this kind is permanent, so it’s important to know what to look out for, this way you can prevent any damage before it takes place.
Signs and Symptoms
After exposure to overly loud sounds, you might notice one of a handful of symptoms that warn you. Immediately after, you may experience tinnitus (ringing in the ears), hearing dullness, a blocked sensation, pain, or even a general sense that you can’t hear as well the next day. These are all signs your ears have been pushed beyond their limits and injury may have occurred. Physiologically, what has occurred is the bending and breaking of a number of minute hair-cells that live within the organ of hearing, our Cochlea. These hair-cells are the sensory cells that help us know when a sound is present. The good news is that they are incredibly resilient, and will bounce back (mostly) after 24 to 48 hours, by which time the symptoms experienced should have subsided.
Hidden Hearing Loss
At first, we believed these temporary symptoms were innocuous, however, we now know this simply isn’t true. Experiencing repeated sound over-exposure has been shown to accelerate the process of age-related hearing loss, presbycusis. This is a natural decline in hearing over time that many people experience later in life, affecting the high frequency hearing more so than the low. It might be hard to care for your ears now, with the future in mind, but we’d certainly argue it’s worth it. The most important impact these temporary changes have, however, is on a hidden pathway we’ve only recently come to terms with.
The auditory nerve carries information from our ear up to the hearing center of our brain. We used to think this was a one-way street, however, thanks to research, we now know it has two separate avenues. In one lane, the nerve carries information about the softest sounds we can hear, in the second lane, it transfers up all the moderate to loud sounds we experience. On a hearing test, we look to measure your softest sounds, and therefore just one pathway up to the auditory cortex. However, it’s this second loud-lane we don’t measure, that is selectively targeted by and extra vulnerable to injury. Injury of this pathway might not show up on a hearing test, hence the term hidden hearing loss, but it will show up in how you hear. For some it can result in reduced tolerance of volume, greater chance of tinnitus, or difficulty understanding speech in the presence of background noise. This is why protecting your hearing goes beyond getting perfect results on a hearing test, it’s about giving yourself the best shot and preserving your functional hearing too.
Either side of our head live two giant funnels to capture sound. As sound waves pass down them a natural resonant boost is given to 2.7 and 6 kHz, the frequencies mother earth decided we needed to hear best. Due to that resonant boost (as well as other more complex cochlear mechanics), hearing loss caused by noise shows on an audiogram (hearing test) with a tell-tale, up-side-down triangle. This triangle is called the ‘noise-notch’ and initially impacts frequencies at and around 3-6 kHz. For workers in a factory setting, this notch pattern is often symmetrical between the ears, but for musicians, it can show up asymmetrically, affecting one ear more than the other. An example of this can be with drummers, who’s left ear is exposed to the high-hat of the kit, or violinist, with their left ear also more affected, closer to the instrument.
Initially this pattern of hearing loss starts in the high frequencies, chipping away at someones ability to hear the softer consonants, such as ‘s’, ‘f’, ‘th’ and ‘sh’. However, if the exposure continues unabated, it can worsen, taking more hearing with it and eventually including the lower frequencies. Interestingly, new research suggests that our extra-high hearing, important for tone and timbre (9- 16 kHz, not shown below), is quite vulnerable to sound overexposure, and part of the reason we recommended having these tested (see What to Expect from A Hearing Test).
A little bit of math
From an occupational setting, health practitioners abide by a guiding principle that the human ear can safely withstand 85 dBA over an 8 hour work period. To keep this balance in check, when the intensity of sound is doubled, the exposure time of the individual is halved. Incredibly, it only takes 3 dB to double the intensity (yes, so small!), so when 85 becomes 88, the recommended exposure time is 4 hours, at 91 – 2 hours, and so on. So much so, that by the time you reach 100 dBA, safe listening exposure is 15 minutes. A rather worrying number when sound levels at concerts have been measured between 81 and 90 (LAeq) for classical music, and 94 and 115 (LAeq) for contemporary genres, such as rock and pop.
To put it simply, ears designed for the quiet of the jungle, where volume meant immediate danger, we’ve certainly created a world that puts them through their paces, where even a city street reaches 85 dBA. It’s easy to see how they can get over-worked and run down and need taking care of.
Smoking and Stress
Beyond hearing loss, studies have shown individuals with repeated exposure to noise and/or loud sounds may present with cardiovascular health issues and stress-related impacts. This is partially because of the effect loud sounds have on our blood vessels, encouraging them to tighten, leading to hypertension. Importantly for our ears, this also means that nasty free-radicals (damage causing molecules which result from noise), can’t as easily leave our ears, increasing the chances of MIHL. Smoking is an interesting conundrum, as it too has this constrictive effect, and its additive influence when combined with loud sound increases the likelihood of hearing loss four-fold! This should be a huge take-home to any musician wishing to protect their ears in the industry, if nothing else, realising that the ciggy break between gigs makes you more susceptible for harm.
Hearing in the music industry
Considering all the above it may come as no surprise that 74% of musicians are reported to experience at least one form of hearing injury, with reports of hearing loss often between 30 and 40%. Tinnitus after a gig, a sign of temporary injury and a precursor to hearing loss, has been reported by over half of patrons after a gig, and more than 80% of sound engineers – so if you’ve experienced it, you’re not alone. The sad thing is that a huge survey in conjunction with MTV, found that over half of respondents said they would personally judge a friend for using hearing protection at live music, suggesting there is still a very real and powerful stigma at play with hearing health. The crazy thing about this, beyond the stigma itself, is that every individual has their own pain-threshold, their own discomfort level and when they’ll start to experience symptoms. Using hearing protection shouldn’t require justifying your actions, but it appears some research suggests so.
Steps to Protect
Ok – so what can you do! It’s not all glum. The best news is, that once exposure to loud sounds has been managed, the damage stops accumulating – so, we just need to get better managing our hearing. If you’re interested in hearing protectors, head here, however, there are more steps you could try, such as:
- Take a break – give your ears the space to breathe and recover during any gig, instead of shouting above the music to have your next chat;
- Don’t creep up the volume – the real likelihood is that during the course of a loud rehearsal or gig your hearing has dulled by up to 6 dB. That’s a reduction x 2 in volume sensation that could lead you to wanting more in compensation. If you catch yourself aware of this, instead of turning it up, step back or plug them up. It’s a sign your ears are getting tired and experiencing harm;
- Get to know your instrument – is it predominately mid-high frequencies, such as a guitar? If yes, these are ultra-directional frequencies that are loud if pointed at you, and considerably less so if pointed away. Next time rehearsing with these, turn or tilt the speaker towards your head and you’ll notice a huge difference, suddenly you’ll be able to have your amp down, and the person next to you – theirs too;
- Play to the room – a well-trained musician knows when to push and pull the volume, and playing to the acoustics of a room are all a part of that. If you clap your hands and hear a really long delay, the likelihood is you’re in an ultra-resonant room where sounds could either swell beautifully (classical), or muddy each other (electronic). If you do so and there’s virtually nothing audible in the sound decay, depending on what you play you might be able to get away with more than before.
A career in music doesn’t mean needing to lose your ability to hear it, if anything it is the path to superior hearing than any of your friends, better auditory function and better speech understanding than they could ever hope for! Be proud of your hearing and let is shine to its full potential. If you feel you’re at risk, take action, and better still, be kind to the mate taking action for theirs.
Feature image by Kate Disher-Quill