A study analysing previous research into young people and their unsafe listening practices has estimated that hundreds of millions of teens and young people around the world are at risk of noise-induced hearing loss.
According to the World Health Organisation (WHO), 430 million people worldwide have disabling hearing loss, and it’s estimated that by 2050 that number will rise to over 700 million – that’s one in ten people.
But young people are particularly vulnerable because they use personal listening devices (PLDs) – like smartphones, headphones, and earbuds – and attend loud entertainment venues, which may mean they exceed safe listening levels.
Even Australian sound engineers are concerned for the hearing of people attending music festivals and concerts.
The new study, in BMJ Global Health, estimates the prevalence of unsafe listening practices from PLDs and loud entertainment venues is common worldwide – occurring in 24% of teens and 48% of young people.
“Estimates of the prevalence of unsafe listening practices, or of the global caseload of young people engaging in unsafe listening practices, are not available in the published literature, although such estimates are needed to promote policy implementation to reduce risk of hearing loss in young people,” the authors write.
“This data will be used to communicate the urgent need to implement policy that promotes safe listening habits to governments, industry, civil society, and other relevant stakeholders.”
The researchers undertook a systematic review of research articles published in English, Spanish, French, and Russian between 2000 and 2021. They identified 33 relevant articles involving 12-34 year-olds that objectively measured sound output levels and length of exposure, corresponding to data from 19,046 individuals.
By analysing the pooled data from these studies, and using estimates of the global population of 12-34 year-olds (2.8 billion), they found between 670 million and 1.35 billion young people are potentially at risk of hearing loss from exposure to unsafe listening practices.
But what exactly are unsafe listening practices? And how do you prevent hearing loss from this in your own life?
What are safe listening practices?
We hear thanks to the cochlear hair cells in our ears, but exposure to loud sounds over time causes them to fatigue and results in temporary hearing loss or tinnitus; that familiar muffled hearing, ringing, or buzzing people often experienced after going to a loud concert or nightclub.
This usually improves as the cells recover, but regular exposure to loud or prolonged noise can result in permanent damage to hair cells and other structures in the ear, eventually leading to irreversible noise-induced hearing loss, tinnitus, or both.
But how do you know what noise levels are safe and for how long you should be exposed to them?
Sound intensity is measured in decibels (dB) which are not like normal numbers because the decibel scale is logarithmic. So an increase of 3 dB represents a doubling of sound energy, and a 3 dB increase in noise level can cause the same amount of damage to the ear in half the time.
As you might expect the amount of time you can safely listen decreases rapidly as the sound’s intensity increases. According to Safe Work Australia, while adults can safely listen to 80 dB(A) sound for 16 hours per day without problem, this duration goes down to just 15 minutes for a 100 dB(A) sound and just 28.8 seconds for a 115 dB(A) sound.
What does that (A) stand for? Well, while decibels are used to measure all sound, dBA is a weighted scale that accounts for the relative loudness perceived by the human ear, since humans don’t hear all frequencies equally.
Today is #WorldHearingDay. You may not notice it, but too much noise at work can lead to hearing loss. Learn how to reduce exposure to noise at— Safe Work Australia (@safe_work_aus) March 2, 2021
the workplace https://t.co/l7Gac5LPGn pic.twitter.com/NakiWMGYYL
So, the unsafe listening practices considered in this study occurred where individuals exceeded these permissible levels. For context, the authors write that published research suggests that PLD users often choose volumes as high as 105 dB(A).
According to Safe Work Australia, workers must not be exposed to above 85 dB(A) on average over eight hours at work in a day, and must not be exposed to a noise level above 140 dB(A).
You can easily monitor the decibel level on your music device with the use of handy apps. The WHO also recommends setting your device’s volume to no more than 60% of the maximum and taking frequent breaks from loud sounds to help the hair cells in your ears recover.
The WHO has extensive information on safe listening.
But how do you keep your hearing safe at truly noisy venues like concerts and music festivals?
As you might expect, depending on where you stand at a concert or nightclub, you’ll experience different sound intensities.
Live sound engineer, Garry Hall, from JPJ Audio Australia manages sound systems at outdoor music events and uses calibrated noise instruments to measure levels in the environment and at workplaces.
“On a well-designed festival concert sound system, the sound will be approximately 3 to 4 decibels louder near the front rows and approximately 3 decibels quieter at the rear, compared to the reference noise monitoring location at the front of house (FOH) mixing position, which is generally 30-40 metres from the stage.”
He says noise levels at the FOH mixing position are generally determined by the noise restrictions at the boundary of the residence, which is usually determined by the state’s Environmental Protection Authority (EPA) restrictions.
“So normally, I would be given noise limit of between 95 and 100 dB (LAEQ) for most music festivals – like Splendour in the Grass, Blues and Roots Festival, Falls Festival,” says Hall.
LAEQ is the A-weighted equivalent continuous sound level, a measure of the average noise level perceived by the human ear over a given period of time.
A 100 dB LAEQ represents a strong sound typical of rock concerts and LAEQ of 95 dB is typical of indie/alternative rock concerts.
According to Hall, nightclub noise levels will be even higher.
So why not just turn down the music?
Well, according to Hall, there’s a minimum music level below which the concert experience will be substandard; an LAeq level of less than 95 dB isn’t sufficiently loud for most music genres and is likely to elicit complaints from event organisers and disgruntled patrons.
So, what does this mean for your concert-going experience? Well, there are apps to monitor the sound levels in the environment around you and while some are more accurate than others it should give you an idea of the kind of sound intensities you’re experiencing.
Keep in mind that you can safely listen to a concert at 94 dB(A) for one hour, or a 97 dB(A) concert for 30 minutes.
Hall wears hearing protection at the FOH position if he isn’t sound mixing, but that often isn’t the case for patrons.
“We’re wearing hearing protection, but a lot of the punters will go to a festival and they’re exposed to music for eight hours at levels between 95 and 100 decibels. So that is a concern,” he says.
So, wearing hearing protection like earplugs and taking regular breaks to rest your ears in quieter areas is a must, as well as standing rear of the FOH if possible.
Imma Perfetto is a science journalist at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.