Do you hear that? Do you know what that is? Silence.
The sound of silence.
Simon and Garfunkel wrote a song about it.
But silence is a prettyrare commodity these days, and we're all paying a price for itin terms of our health — a surprisingly big price, as it turns out.
Luckily, there are thingswe can do right now, both individually and as a society, to better protect our health and give us more of the benefitsof the sounds of silence.
I assume that most of you know thattoo much noise is bad for your hearing.
Whenever you leave a concert or a barand you have that ringing in your ears, you can be certain that you have donesome damage to your hearing, likely permanent.
And that's very important.
However, noise affects our healthin many different ways beyond hearing.
They're less well-known, but they're just as dangerousas the auditory effects.
So what do we meanwhen we talk about noise? Well, noise is defined as unwanted sound, and as such, both hasa physical component, the sound, and a psychological component, the circumstances that makethe sound unwanted.
A very good example is a rock concert.
A person attending the rock concert, being exposed to 100 decibels, does not think of the music as noise.
This person likes the band, and evenpaid a hundred dollars for the ticket, so no matter how loud the music, this person doesn't think of it as noise.
In contrast, think of a person livingthree blocks away from the concert hall.
That person is trying to read a book, but cannot concentratebecause of the music.
And although the sound pressure levelsare much lower in this situation, this person still thinksof the music as noise, and it may trigger reactions that can, in the long run, have health consequences.
So why are quiet spaces so important? Because noise affects our healthin so many ways beyond hearing.
However, it's becoming increasinglydifficult to find quiet spaces in times of constantly increasing traffic, growing urbanization, construction sites, air-conditioning units, leaf blowers, lawnmowers, outdoor concerts and bars, personal music players, and your neighbors partying until 3am.
Whew! In 2011, the World HealthOrganization estimated that 1.
6 million healthy life yearsare lost every year due to exposure to environmental noise in the Western Europeanmember states alone.
One important effect of noiseis that it disturbs communication.
You may have to raise your voiceto be understood.
In extreme cases, you may evenhave to pause the conversation.
It's also more likely to be misunderstoodin a noisy environment.
These are all likely reasonswhy studies have found that children who attendschools in noisy areas are more likely to lag behind their peersin academic performance.
Another very importanthealth effect of noise is the increased riskfor cardiovascular disease in those who are exposedto relevant noise levels for prolonged periods of time.
Noise is stress, especially if we have littleor no control over it.
Our body excretes stress hormoneslike adrenaline and cortisol that lead to changesin the composition of our blood and in the structure of our blood vessels, which have been shown to be stifferafter a single night of noise exposure.
Epidemiological studies show associationsbetween the noise exposure and an increased riskfor high blood pressure, heart attacks and stroke, and although the overall risk increasesare relatively small, this still constitutesa major public health problem because noise is so ubiquitous, and so many people are exposedto relevant noise levels.
A recent study found that US society could save 3.
9 billion dollars each year by lowering environmentalnoise exposure by five decibels, just by saving costs for treatingcardiovascular disease.
There are other diseaseslike cancer, diabetes and obesity that have been linked to noise exposure, but we do not have enough evidence yet to, in fact, conclude that these diseasesare caused by the noise.
Yet another important effect of noiseis sleep disturbance.
Sleep is a very active mechanismthat recuperates us and prepares us for the next wake period.
A quiet bedroom is a cornerstoneof what sleep researchers call “a good sleep hygiene.
” And our auditory systemhas a watchman function.
It's constantly monitoringour environment for threats, even while we're sleeping.
So noise in the bedroom can cause a delayin the time it takes us to fall asleep, it can wake us up during the night, and it can prevent our blood pressurefrom going down during the night.
We have the hypothesis thatif these noise-induced sleep disturbances continue for months and years, then an increased risk for cardiovasculardisease is likely the consequence.
However, we are often not awareof these noise-induced sleep disturbances, because we are unconsciouswhile we're sleeping.
In the past, we've done studieson the effects of traffic noise on sleep, and research subjects would oftenwake up in the morning and say, “Ah, I had a wonderful night, I fell asleep right away, never really woke up.
” When we would go backto the physiological signals we had recorded during the night, we would often see numerous awakenings and a severely fragmented sleep structure.
These awakenings were too brieffor the subjects to regain consciousness and to remember themduring the next morning, but they may neverthelesshave a profound impact on how restful our sleep is.
So when is loud too loud? A good sign of too loud isonce you start changing your behavior.
You may have to raise your voiceto be understood, or you increase the volume of your TV.
You're avoiding outside areas, or you're closing your window.
You're moving your bedroomto the basement of the house, or you even havesound insulation installed.
Many people will move awayto less noisy areas, but obviously not everybodycan afford that.
So what can we do right nowto improve our sound environment and to better protect our health? Well, first of all, if something's too loud, speak up.
For example, many owners of movie theaters seem to think that only people hardof hearing are still going to the movies.
If you complain about the noiseand nothing happens, demand a refund and leave.
That's the language that managerstypically do understand.
Also, talk to your childrenabout the health effects of noise and that listening to loud music todaywill have consequences when they're older.
You can also move your bedroomto the quiet side of the house, where your own building shields youfrom road traffic noise.
If you're looking to rentor buy a new place, make low noise a priority.
Visit the property duringdifferent times of the day and talk to the neighbors about noise.
You can wear noise-canceling headphoneswhen you're traveling or if your office has highbackground noise levels.
In general, seek out quiet spaces, especially on the weekendor when you're on vacation.
Allow your system to wind down.
I, very appropriately for this talk, attended a noise conferencein Japan four years ago.
When I returned to the United Statesand entered the airport, a wall of sound hit me.
This tells you thatwe don't realize anymore the constant degreeof noise pollution we're exposed to and how much we could profitfrom more quiet spaces.
What else can we do about noise? Well, very much like a carbon footprint, we all have a noise footprint, and there are things we can doto make that noise footprint smaller.
For example, don't start mowing your lawnat 7am on a Saturday morning.
Your neighbors will thank you.
Or use a rake instead of a leaf blower.
In general, noise reduction at the sourcemakes the most sense, so whenever you're lookingto buy a new car, air-conditioning unit, blender, you name it, make low noise a priority.
Many manufacturers will listthe noise levels their devices generate, and some even advertise with them.
Use that information.
Many people think that stronger noiseregulation and enforcement are good ideas, even obvious solutions, perhaps, but it's not as easy as you may think, because many of the activitiesthat generate noise also generate revenue.
Think about an airport and allthe business that is associated with it.
Our research tells politiciansat what noise level they can expect a certain health effect, and that helps inform better noise policy.
Robert Koch supposedly once said, “One day, mankind will fight noiseas relentlessly as cholera and the pest.
” I think we're there, and I hope that we will win this fight, and when we do, we can all havea nice, quiet celebration.
(Laughter) Thank you.