What is a safe exposure level to prevent hearing loss?
It depends on how long a person is in that environment. As a general rule, we say a worker can be in an environment that's 85 decibels for about eight hours a day safely. If you go into a louder environment, you get less safe time. So once you hit 88 decibels, you get four hours of safe exposure time, 91 decibels, you get two hours of safe exposure time, and so on.
That said, we want to understand and reduce our exposure whenever possible. A simple way to do that is to use a sound-level meter app. There’s a great one from the National Institute of Occupational Safety and Health (the NIOSH SLM app) – it’s pretty accurate for a free app on your phone.
Exposures are also cumulative over the course of a day. If you work in a noisy environment all day long and then you go home and you mow the lawn, that's adding one more noise exposure. You should be mindful of your recreation activities, whether that's listening to music, riding ATVs, using power tools and woodworking, or for hunters with recreational firearm use – the latter probably being the biggest risk factor for hearing loss.
Is the sustained exposure more damaging overall?
Sustained exposures are what we can certainly prevent, and are also the riskiest daily activity.
However, noise exposure is a little bit hard for people to wrap their brain around because some people have really tough ears, and some people have really tender ears. Two people can work in the same job around the same amount of noise and end up with totally different hearing later in life. We know that some people are more susceptible to damage to the ear from loud noise, but we don't know who those people are. We have no way to test risk, which is why we suggest everybody takes extra caution.
Is hearing sensitivity primarily genetic then?
We think so. We think there are genetic factors that make somebody more predisposed to having hearing loss, more susceptible to noise damage. There are also environmental factors. There are medications that make you more susceptible to hearing loss, like chemotherapy medications for cancer, for example. But it's mostly genetically mediated. But at present, we don't have any genetic tests that tell what your hearing loss risks are.
Is hearing loss permanent?
Hearing loss is permanent when it happens, so when you lose it, it doesn't come back. We want to be extra cautious with hearing protection, so that we're not prematurely aging our ears.
As a concerned millennial who has listened to his share of loud music: Have you and your colleagues seen an uptick in hearing loss in younger generations?
So at a statistical level, we're not actually seeing a big increase in hearing loss rates amongst younger adults and teenagers. Part of that is because our data haven't really been around long enough to see some of that. I suspect as we look at sort of statistical data moving a little bit forward, in 10 years, we might start seeing some of those changes.
For personal use on your phone or an MP3 player, is the 80-90 rule still the medical advice that you would give?
Absolutely. That's still the recommendation that we provide. The 80-90 rule is: You can listen to 80% of the max volume for 90 minutes a day safely. If you want to be really safe, take it down to 70%, and you can listen for most of the day safely.
So for personal music headphones, noise canceling versus noise isolating, do you recommend one or the other?
First off – we recommend that if you are listening to music in a noisier environment, if there's sound around you that causes you to raise the volume of your music so you can hear it, it's a good idea to try to reduce the outside sound. You can do it in two ways. One is noise-isolating earphones. So headphones that block out background noise physically by sealing up your ear. The other option is noise-canceling earphones, which use an active electronic to try to reduce sound.
Noise-canceling headphones work great in steady background noise. So transportation noises, for example, the sound of a bus or the sound of a plane, they work great. But for variable-noise environments – a coffee shop with a bunch of people talking – noise-canceling headphones don’t work nearly as well as noise-isolating earphones.
But honestly, both work fine. Use what you're comfortable with. If we know one thing in the world of preventing hearing loss, it is: If the solution doesn't work for you, you're not going to do it. So choose the solution that works the best for you.
As an audiologist, do you bring earplugs to concerts or whenever you're doing noisy home improvement work?
If I'm going to a concert, I always bring earplugs. I keep an extra set in the car actually just as a backup in case I need something. Doing housework, I'm usually not wearing them. But if I'm doing a project, I like to have hearing protection available for when I'm using those louder tools. I'll hang a set of over the ear earmuffs right next to my miter saw, for example.
How do you identify hearing loss when it can happen over decades, and your primary care doctor might not screen for it? What are some warning signs?
If you have ringing or buzzing in your ears (tinnitus), it's a good idea to have your hearing checked. We're concerned about persistent tinnitus particularly. If you have ringing in your ears that lasts for a few seconds to a few minutes, that's totally harmless and happens to just about everybody.
Also, if you start having difficulty understanding conversations in background noise. If you find that you are getting regularly frustrated in conversations because it's harder to understand, that's a concern for us. Or if you feel like you're missing sounds that other people might be hearing or identifying, like birds chirping in the distance, for example.
We recommend seeing an audiologist or having a hearing test if you have any concerns at all. We could always test your hearing and say, ‘Hey, everything's great.’ But it's better to know earlier if you're at risk. For those with high levels of noise exposure, either professionally or through recreation activities, we recommend monitoring your hearing every year with a hearing test.
Over-the-counter hearing aids have now been approved. How do you feel about that recent move?
We are excited to see competition in the industry and push our technology forward and potentially provide greater access for more people by creating some lower-cost devices.
On the other hand, what's on the market today that you can buy over the counter are not good quality. I think we'll see changes to that in the next six to nine months, but right now we're not seeing that. A related challenge is that one of the big ways that you're saving money with over-the-counter hearing aid is by getting rid of that professional service component. You lose the professional to help you to know how to use the devices, provide rehabilitation services and make sure that devices are properly fit for you.
There are some types of hearing losses which are medically treatable. And we'd much rather see people understand their ears and their hearing before they go out and purchase a hearing aid. In many cases, an audiologist can help make over-the-counter devices work better, or we can look at reasonably priced prescription hearing aids. We strongly recommend that everyone see an audiologist for a hearing evaluation before purchasing a hearing aid, whether over-the-counter or by prescription.
