Changing Environments Spotlight Need for More Hearing Protection Research

How many times a day do you think about your ears? If you're like most of us, the honest answer is: zero. Yet, in the workplace, in the home, and out in public, we're expecting our ears to perform like never before.

At work, we just assume we'll be able to hear colleagues' voices, ringing phones, even fire-drill alarms. At home, we're being introduced to voice-activated devices that speak to us in soothing-but-earnest tones, answering our questions and playing our favorite songs on command. Out in public, we're treated to a cacophony of competing noises that we expect our ears to filter so we can decipher which ones deserve our immediate attention.

Most of us accept the rising levels and increasing sources of noise around us as normal everyday life. Like the proverbial frog and the boiling pot of water, however, we are blissfully unaware of these noises' cumulative effects on our hearing — because we experience each noise-level increase incrementally. If we could beam ourselves Star Trek-style to a remote desert island, then come back an hour later, we would acutely feel the sudden rush of sounds swirling around us upon returning.

Take a little noise inventory of your own sometime. Baristas are yelling orders over hissing cappuccino makers. Burrito makers are asking customers to pick their ingredients as loud music streams in the background. Food truck customers are shouting over traffic noise. Digital out-of-home media in convenience stores is blaring cable news or branded programming on TV screens. Airports are making garbled announcements from overhead speakers, while loudly beeping people-mover carts weave through crowds like salmon swimming upstream.

Audiologists generally agree that we should wear hearing protection when we are exposed to sounds of 85 decibels (abbreviated as dB or dBA) or more. By way of comparison, the typical human voice is about 64 dBA. A leaf blower is about 90 dBA. A jackhammer is approximately 105 dBA. (Discover more examples at HearingAtWork.org, which also offers free ear plugs and links to noise-level apps.)

In addition to the loudness of a noise, we need to pay attention to how much time we're exposed to it. For every 3 dBA increase above 85 dBA, the amount of time before hearing damage occurs is cut in half.

Of course, for those of us who are just passing through these places, our exposure to all those decibels — the metric used to measure the volume level of a sound — might feel limited and somewhat within our own control. We can always walk out of the coffee shop or store if the noise level feels uncomfortable.

But what about the people who can't simply walk out — the employees? New and novel work environments combined with a constantly evolving multicultural and multilingual workplace have created an obstacle course for occupational hearing.

Human resources and safety specialists in large industrial work settings commonly know these facts about noise exposure, and usually provide hearing protection and appropriate worker training to minimize the risk of injury and hearing loss. Smaller companies with tighter budgets and less knowledge about hearing protection often have gaps in their policies and training.

How does all that noise affect people at work? What does it do to their job performance, their mental focus, their communication ability? How does workplace noise affect the bottom line?

Not even Alexa or Siri knows the answers to those questions. In fact, one of the things we know in the workplace safety and hearing protection communities is how much we don't know.

We urgently need more research, because all of those questions — and others like them — are really important. Here are four key areas of research that would help industries and the hearing protection community deepen their understanding and ability to respond.

Noise Impacts: What types and levels of noise are people exposed to at work and in their personal lives — paying particular attention to new occupations and work environments, as well as recent in-home technology changes — and how does exposure to all that new noise affect people?

Hearing Loss Mechanisms: We need a deeper understanding about how the mechanisms of hearing loss work. For example, what sound frequencies and patterns of exposure put people at greater risk? There's a lot more awareness of how the sun's rays affect our skin than there is about how sound waves affect our hearing over the course of our lives.

Chemicals: We know that certain chemicals and medications are "ototoxic" — physically harmful to ears and hearing. Common examples include aspirin, lead, and chemotherapy drugs. Cigarette smoking, too, since it deprives the body of oxygen and causes the inner ear to slowly suffocate. But we need a lot more knowledge about how various agents interact with the human ear.

Prevention: First and foremost, ear plugs are the best line of defense against hearing loss. Researchers also tell us that, ironically, other chemicals can have a positive effect on our hearing by protecting our ears from hearing loss. For example, antioxidants in food may help protect our hearing. What dietary steps can we take to boost our hearing health?

Audiologists and other hearing specialists no doubt would add to or refine that list. But my point is simple: More research is needed to advance society's knowledge about how our increasingly noisy world affects our hearing, and about how we can better protect this sense that enables us to enjoy and interact with one another and the world around us.

Why do I care so much about hearing protection? Because I have hearing loss myself, and I know all too well that failing to appreciate, understand, and care for our hearing hastens the day when it permanently disappears and changes our lives forever.

Charles D. Johnson is president of the International Safety Equipment Association and a passionate advocate for hearing protection.

Posted on Jun 01, 2018