A revised definition of noise for National Protect Your Hearing Month

Photo credit: Chris Fithall licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

October is National Protect Your Hearing Month, and I am using the occasion to propose a revised definition of noise: noise is unwanted and/or harmful sound.

For many decades, noise has been defined as “unwanted sound,” a phrase usually attributed to the late acoustics pioneer Leo Beranek. The problem with this definition is that it implies that the perception of noise is subjective. This means that those complaining about noise have no real basis for their complaints, other than a personal reaction to noise.

The new definition acknowledges that noise can be harmful to human health and can interfere with human activity. Even if a noise is merely unpleasant, that experience is stressful.  Recent research shows that stress causes vascular inflammation and cardiovascular disease.

The revised definition is supported by my article in the Fall 2019 issue of Acoustics Today, summarizing the evidence-based noise levels affecting human health and function. My article makes it clear that there can be no rational doubt that noise is harmful, and unwanted noise especially so. Sounds as quiet as 30-35 A-weighted decibels (dBA) can disrupt sleep. A good night’s sleep is important for health and function. Forty-five decibel (dB) sound can disrupt concentration and interfere with learning. At 55 dB, non-auditory health impacts of noise begin, including hypertension, cardiovascular disease, and increased mortality. These effects are best studied for transportation noise, but are seen with occupational noise exposure. At 60 dBA ambient noise, people with hearing loss have difficulty understanding speech. At 70 dBA, those with normal hearing also have difficulty understanding speech.

Seventy dB time-weighted average for 24 hours is the only evidence-based noise exposure level to prevent hearing loss, but the actual safe noise level is probably lower than that. And 85 dBA is the occupational recommended noise exposure level, not a safe noise level for the public. And as I notedin my article, the World Health Organization recommends only one hour exposure at 85 dBA daily to prevent hearing loss. Because the decibel scale is logarithmic, this is mathematically the same as 70 dB time-weighted average for a day.

Hearing loss is very common in older people, but I’ve learned that this isn’t part of normal physiological aging. Rather, presbycusis or age-related hearing loss is largely noise-induced hearing loss.

So what can you do to protect your hearing? There are two ways to protect hearing: avoid loud noise, and if you can’t, use hearing protection devices.

We only have two ears, and unlike knees they can’t be replaced. So if a noise sounds too loud, it IS too loud. And if a noise is so loud that one can’t converse without straining to speak or to be heard, the ambient noise is above 75 dBA and your hearing is at risk.

And always remember that noise is unwanted and/or harmful sound

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He is the founding chair of The Quiet Coalition, an organization of science, health, and legal professionals concerned about the impacts of noise on health, environment, learning, productivity, and quality of life in America. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

Comments (5)

  1. Mike Ewald

    …………………..

    I use 32 db rated foam earplugs all the time–even inside–
    along with a sleep sound machine resting against my chin in various positions while sleeping, for the “white” fan noise as well as the vibration/hum of the motor to block the perpetual assault of a high-density commercial business next door.
    Fifty, mostly large, whole-house-rumbling trucks every week (seven-nine average daily-over six days and a few now on Sundays, along with often voluminous traffic and all the accompanying noise, malodors, etc, only twenty-five feet away (about three from another resident’s home) make for very unpleasant and obnoxious conditions.
    ~Not everyone can afford to relocate……

    ~I discovered an excellent video on Youtube recently regarding vibroacoustic disease resulting from not only loud noise, but also from infrasound/ low frequency noise….like that produced by….wind turbines….
    especially when constructed and operated near homes, etc.
    It is presented by Dr. Mariana Alves Pereira, with degrees in Physics, Biomedical Engineering, and Environmental Science.
    She presents easy to understand insight into just how detrimental all kinds of noise/sound can be and is to our health and especially children.

    (Having constant, usually low level tinnitus doesn’t help.)

    The Youtube video is provided by Yoryevrah and is an invaluable resource.

    Reply
  2. Daniel Fink MD

    Mike
    It sounds (so to speak) like you have a problem situation. Are there any municipal codes that might apply? I know Dr. Alves Pereira and her work on vibroacoustic disease, which is underappreciated on this side of the Atlantic. Good luck.
    Dan

    Reply
  3. Michael

    High information content of neighbour noise, which I am going to explore in this post, is also damaging to human health not just loud noises.

    Associate Professor Diana Weinhold’s (London School of Economics) most recent paper (2018) and draws upon research in a study from 2008 to 2013 which found:

    “Overall we find surprisingly strong and robust effects of residential noise annoyance on a variety of health outcomes, including cardio-vascular symptoms, auto-immune conditions associated with joint and bone disease, headache, and fatigue. The relationship is not only statistically significant but also of a meaningful magnitude. Controlling for sleep disruption only provides a partial explanation, suggesting additional physiological mechanisms. Finally, we find neighbour noise to be relatively more damaging to health than street noise.”

    Weinhold also relied upon research by Niemann who wrote in 2006:

    “The predominant source of noise annoyance in residential quarters is traffic followed by neighbourhood noise. Usually, neighbourhood noises are sounds with high information content such as language, music or also the noise of footsteps. It is in the nature of humans to have their attention drawn to such informative sounds, even if the sound level is relatively low. The annoyance potential of neighbourhood noise is therefore relatively high also at low noise levels and is heightened by the hearer’s knowledge of the sound producer and other things causing the noise. Policymakers, the public and many experts still underestimate the health impacts of noise in the residential environment.”

    In reference to your article that sounds as low as 30 db (A) can be damaging to your health, Kuwana performed experiments in 2002:

    Playing sound as low as 25db(A) and finding that karaoke and people talking prevented people sleeping 70% of the time and 20% of the people could not sleep after the sound was turned off. When the level of road traffic noise was 25 dB(A) and when the simulated air-conditioner noise was exposed, most of the subjects fell asleep listening to the sound.

    Our brains are wired physiologically to hear high information content at extremely low noise level.

    You know that policymakers, judges/courts and law enforcement do not understand the profound health consequences of neighbour noise and what is reasonable.

    The idea that neighbour noise is give and take with the concept of what is reasonable is an abomination constantly victimising the victim.

    Why can’t they understand that sleep is a fundamental human right and human need?

    Do we really need Maslow’s hierarchy of needs to explain the elephant in the room.

    A neighbour can’t take away your dinner, then why sleep?

    I would be interested in discussing this further.

    Reply
  4. Daniel Fink

    Michael
    Thanks so much for your comment. I will track down the references you mentioned. I am writing a manuscript about the new definition, and have tracked down the first use of the definition “noise is unwanted sound” to 1931, when it was cited in a book as being developed by a committee of the nascent Acoustical Society of America.

    In 1931 the adverse effects of noise on health and human function weren’t known, or certainly weren’t researched as intensively as today. What I am trying to do with the new definition is to make both acoustic engineers and scientists and policy makers aware that noise is a health and public health hazard.

    Dan

    Reply
  5. Michael

    I’m sure they knew about the dangers of “noise” long before we think. Maybe FDR’s new deal had something to do with the definition in 1931 to improve working and living conditions.
    Noise mostly affects people on low income because policy makers and researchers aren’t interested because they aren’t exposed.
    I would like to reiterate that law enforcement, town planners, building developers, judges and medical professionals (they have no excuse) need to know that noise is a health hazard. If you can hear neighbour noise in you own home then it is too loud.
    Weinhold, in her research paper likened exposure to neighbour noise comparable to a history of smoking.

    Reply

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