Noise exposure directly damages rat brains. What does it do to humans?

Daniel Fink, MD, Chair, The Quiet Coalition

The evidence keeps mounting, almost on a daily basis, that noise is a health and public health hazard. Just last month, an article by researchers in Italy found that noise exposure directly damaged rat brains, producing changes in DNA, neurotransmitters, and even morphological changes. (For those who might be skeptical of this report, there is an existing body of research on the effects of noise on the brain. I don’t understand the details of the newer scientific studies, and I’m always cautious because studies have shown that positive results get reported more frequently than negative results, but taken together with the new report, there is a large amount of research pointing to a direct effect of noise on the brain.)

The Italian study exposed rates to noise of 100 decibels for 12 hours. That level exceeds exposure levels for most humans–certainly for a half-day period–but probably not cumulatively for many who attend clubs, rock concerts, or have noisy hobbies such as woodworking or motorcycle riding.

Humans and rats are genetically very similar–experts argue about whether the rat and human genomes are 97% or 99% similar, and about how to measure this similarity–but regardless of the exact percentage, we’re not talking about applying data from a roundworm to humans. The basic similarities are there in organ and cellular biochemistry, structure, and function. So it’s very likely that noise is also a direct toxin to the human brain, with similar genetic, neurotransmitter, and morphological changes, and most likely at lower noise exposure levels, too.

So what can we do? The solution is simple: avoid loud noise exposure, and wear hearing protection if you can’t.

And one last thing–encourage legislators, regulators, and public health authorities to do more to protect us from exposure to unnecessary noise.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He serves on the board of the American Tinnitus Association, is the interim chair of Quiet Communities’s Health Advisory Council, and 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.

Comments (4)

  1. Jan Mayes

    If manufacturers of headphones/earbuds for personal listening were required to meet loudness limiting hearing protection standards by govts/regulators (e.g. like loudness limiting standards already in place for hearing protection industry e.g. ANSI) it would prevent many many people of all ages from ear damage from loud personal music/noise. Also needed for toys. Shouldn’t there be some type of protection for consumer products that cause invisible ear damage?? I don’t know how to fight for this or get change started.

    1. GMB (Post author)

      There should be real limits and protections. Thing is, some of us think the limit should be under 75 dBA. No manufacturer is going to do that voluntarily. Sadly, nothing will be done until the first kids to abuse earbuds are old enough to suffer early onset hearing loss. Could be soon.

  2. A McIver

    Governments in the UK & USA deliberately downplay noise pollution as a public health problem and are happy to give underfunded, underpowered or compromised bodies the task to ‘regulate’ the powerful transport organisations that create much of the pollution. Why? These governments emphasise the needs of business, commerce & ‘cost effective solutions’. The cost of noise pollution is borne by the individual through ill health and degradation of functionality, the savings of not having to deal with their pollution increases the margins of the corporations.

    1. GMB (Post author)

      We couldn’t agree with you more. Another instance where the pollution costs are externalized. That’s why I am a co-founder of The Quiet Coalition (url =, 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. The U.S. is so far behind the EU and the UK, and The Quiet Coalition aims to get us up to speed.


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