By Dr. Mercola
People who suffer from high-frequency hearing loss in both ears have typically been chronically exposed to loud noise, such as at work.
The National Institutes of Health even states that about 15 percent of Americans between the ages of 20 and 69 have high-frequency hearing loss related to noise exposure during occupational or leisure activities.1
While there are now government standards that regulate allowable noise exposures at work, prior to the mid-1960s no laws were in place to mandate the use of devices to protect hearing. Further, even with such laws in place, many people still suffer from noise-induced hearing loss.
In fact, excessive noise exposure is the most common cause of hearing loss in the US. Noise exposure isn't only damaging to your ears, however. It's also damaging to your heart.
Long-Term Exposure to Loud Noise Raises Your Risk of Heart Disease
Researchers with the University of Kentucky College of Public Health in Lexington analyzed data from more than 5,200 people ranging in age from 20 to 69.
Those who suffered from high-frequency hearing loss in both ears were twice as likely to also have coronary heart disease compared to those with normal hearing.2
The link was even stronger among those aged 50 and under, who were the age group most likely to be exposed to loud noise at work; bilateral high-frequency hearing loss in this age group was associated with a four-fold increased risk of heart disease.
Although the study can't prove that noise was directly related to heart disease, no such association was found among people with one-sided hearing loss or low-frequency hearing loss (which are less likely to be due to noise exposure).
This further strengthens the link between noise-induced hearing loss and heart disease.3
Noise Raises Stress Levels… A Key Risk Factor for Heart Disease
It might seem surprising that excessive, chronic noise exposure could harm your heart, but think about it in terms of stress.
It's estimated that 100 million people are exposed to unhealthy levels of noise, typically from automobile and aircraft traffic (although everything from leaf blowers and lawnmowers to loud music can also contribute).4
This is stressful, and when you're exposed to loud noise stress hormones such as cortisol, adrenaline, and noradrenaline become elevated. Over time, this can lead to high blood pressure, stroke, and heart failure.
One review of research showed that "arousal associated with nighttime noise exposure increased blood and saliva concentrations of these hormones even during sleep."5
Deepak Prasher, a professor of Audiology at University College in London and a member of the WHO Noise Environmental Burden of Disease working group, states:6
"Many people become habituated to noise over time… The biological effects are imperceptible, so that even as you become accustomed to the noise, adverse physiological changes are nevertheless taking place, with potentially serious consequences to human health.
… Taken together, recent epidemiologic data show us that noise is a major stressor that can influence health through the endocrine, immune, and cardiovascular systems."
The impact can be significant. Among women who judge themselves to be sensitive to noise, chronic noise exposure increased the risk of cardiovascular mortality by 80 percent!7 Chronic noise exposure also leads to health risks beyond your heart and hearing, such as diminished productivity, sleep disruption, impaired learning, and more.
How Much Noise Is Too Much for Your Heart?
The World Health Organization (WHO) Noise Environmental Burden of Disease working group calculated just how much noise exposure could be putting your heart at risk.
The "noise threshold" for heart problems was determined to be a chronic nighttime exposure of at least 50 A-weighted decibels, which is the amount of noise created by light traffic.8
And according to research published in Environmental Health Perspectives, long-term exposure to traffic noise may account for approximately 3 percent of coronary heart disease deaths (or about 210,000 deaths) in Europe each year.9
This is an important point to consider, since those exposed to chronic traffic noise also tend to be chronically exposed to another heart health risk – air pollution.
Exposure to fine particle air pollution increased "thoracic aortic calcification" (TAC) scores, a measure of arterial hardening, by nearly 20 percent while exposure to noise pollution increased TAC by about 8 percent.10
This was after controlling for other variables that may influence heart health, such as age, gender, smoking, physical activity, alcohol use, and more. What this means is that people living in high-risk areas need to account for both types of pollution – air and noise – to protect their heart health. As researchers noted:11
"… [B]oth exposures seem to be important and both must be considered on a population level, rather than focusing on just one hazard."
Decreasing Noise Pollution Could Save Nearly $4 Billion a Year
Reducing noise pollution could easily save billions in economic costs, according to an environmental assessment of US noise pollution as a cardiovascular health hazard.
The analyses suggested that a 5-decibel noise reduction would reduce the prevalence of high blood pressure by 1.4 percent and coronary heart disease by 1.8 percent. The annual economic benefit was estimated at $3.9 billion.12
Despite these potential savings to the economy and health benefits to the public, no federal authorities are currently investigating noise and its effect on public health.
The US Environmental Protection Agency (EPA) used to run the Office of Noise Abatement and Control (ONAC) to study such issues and carry out investigations into excessive noise.
However, in 1981 it was determined that noise issues should be handled at the state and local levels, so the ONAC was closed.13 Since no one's been "minding the store," so to speak, concerning nationwide noise pollution, the researchers of the above-mentioned assessment assumed that noise exposure levels in 2013 were the same as those assessed in 1981.
However, as urbanization has increased it's likely these are underestimates and reductions in noise may impact even more people than the study suggested.14 Senior author Richard L. Neitzel of the University of Michigan School of Public Health in Ann Arbor told Reuters:15
"Most of Western Europe is far ahead of the U.S. in understanding people's noise exposure.
In the U.S. the most recent noise exposure data we have is almost 40 years old, 'whereas in Europe they have requirements to map out and understand who's exposed to noise and have requirements to do something about it. In the U.S. we just view it as a necessary byproduct of the technology we use.'"
5 More Ways Noise Pollution May Be Harming Your Health
While air pollution has received considerable attention as a recognized health threat, noise pollution is still flying by under the radar in many areas. As a result, you may be exposed to excessive levels of noise that you've learned to live with… at the expense of your health. Beyond the risks to your heart, exposure to chronic noise pollution may lead to:
- Physio-psychological effects including headache, exhaustion, speech interference, aggravated depression, irritation, and annoyance and loss of concentration16
- Negative impacts on cognitive development in children and cognitive and psychological functions in adults, although more research is needed in this area17
- Among pregnant women, lower birth weight18
- Sleep disturbances, which is why nighttime noise pollution is thought to be worse than daytime exposures
- A significant reduction in testosterone levels, which is associated with psycho-social dysfunction and chronic disease, in male rodents19
Protect Yourself from Noise Pollution with These Simple Steps
If you work in a noisy environment be sure you are wearing ear protection at all times, and leave the site as often as possible, such as during breaks and lunch. Also be cognizant of noise exposures during your leisure time, such as that from motorcycles, lawnmowers, leaf blowers, and even loud music and television.
Try to make less noise when you can, not only for your own sake but also for the sake of those around you. If noise pollution in your home is an issue, and you can't remove the source of the noise or relocate to a new area, consider adding acoustical tile to your ceiling and walls to buffer the noise. Double-paneled windows and insulation can also help, as can adding heavy curtains to your windows, rugs to your floors, and sealing air leaks. If noise is only an issue occasionally, sound-blocking headphones can eliminate such disturbances.
If noise is an issue during the night, you may want to consider adding pink noise to your bedroom. Pink noise is steady with a consistent frequency, like the sound of wind or constant rain. Research shows that steady pink noise can help slow down and regulate your brainwaves for more stable sleep and improved sleep quality.20 While pink-noise CDs are available, you can also simply turn on a fan in your bedroom to block out noise disturbances and instead take advantage of this beneficial type of pink noise.