Why noise is bad for your health and what you can do about it Mathias Basner
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 pretty
rare commodity these days,
and we’re all paying a price for it
in terms of our health –
a surprisingly big price, as it turns out.
Luckily, there are things
we can do right now,
both individually and as a society,
to better protect our health
and give us more of the benefits
of the sounds of silence.
I assume that most of you know that
too much noise is bad for your hearing.
Whenever you leave a concert or a bar
and you have that ringing in your ears,
you can be certain that you have done
some damage to your hearing,
likely permanent.
And that’s very important.
However, noise affects our health
in many different ways beyond hearing.
They’re less well-known,
but they’re just as dangerous
as the auditory effects.
So what do we mean
when we talk about noise?
Well, noise is defined as unwanted sound,
and as such, both has
a physical component, the sound,
and a psychological component,
the circumstances that make
the 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 even
paid 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 living
three blocks away from the concert hall.
That person is trying to read a book,
but cannot concentrate
because of the music.
And although the sound pressure levels
are much lower in this situation,
this person still thinks
of 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 health
in so many ways beyond hearing.
However, it’s becoming increasingly
difficult 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 Health
Organization estimated
that 1.6 million healthy life years
are lost every year
due to exposure to environmental noise
in the Western European
member states alone.
One important effect of noise
is that it disturbs communication.
You may have to raise your voice
to be understood.
In extreme cases, you may even
have to pause the conversation.
It’s also more likely to be misunderstood
in a noisy environment.
These are all likely reasons
why studies have found
that children who attend
schools in noisy areas
are more likely to lag behind their peers
in academic performance.
Another very important
health effect of noise
is the increased risk
for cardiovascular disease
in those who are exposed
to relevant noise levels
for prolonged periods of time.
Noise is stress,
especially if we have little
or no control over it.
Our body excretes stress hormones
like adrenaline and cortisol
that lead to changes
in the composition of our blood
and in the structure of our blood vessels,
which have been shown to be stiffer
after a single night of noise exposure.
Epidemiological studies show associations
between the noise exposure
and an increased risk
for high blood pressure,
heart attacks and stroke,
and although the overall risk increases
are relatively small,
this still constitutes
a major public health problem
because noise is so ubiquitous,
and so many people are exposed
to relevant noise levels.
A recent study found that US society
could save 3.9 billion dollars each year
by lowering environmental
noise exposure by five decibels,
just by saving costs for treating
cardiovascular disease.
There are other diseases
like 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 diseases
are caused by the noise.
Yet another important effect of noise
is sleep disturbance.
Sleep is a very active mechanism
that recuperates us
and prepares us for the next wake period.
A quiet bedroom is a cornerstone
of what sleep researchers call
“a good sleep hygiene.”
And our auditory system
has a watchman function.
It’s constantly monitoring
our environment for threats,
even while we’re sleeping.
So noise in the bedroom can cause a delay
in the time it takes us to fall asleep,
it can wake us up during the night,
and it can prevent our blood pressure
from going down during the night.
We have the hypothesis that
if these noise-induced sleep disturbances
continue for months and years,
then an increased risk for cardiovascular
disease is likely the consequence.
However, we are often not aware
of these noise-induced sleep disturbances,
because we are unconscious
while we’re sleeping.
In the past, we’ve done studies
on the effects of traffic noise on sleep,
and research subjects would often
wake 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 back
to 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 brief
for the subjects to regain consciousness
and to remember them
during the next morning,
but they may nevertheless
have a profound impact
on how restful our sleep is.
So when is loud too loud?
A good sign of too loud is
once you start changing your behavior.
You may have to raise your voice
to 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 bedroom
to the basement of the house,
or you even have
sound insulation installed.
Many people will move away
to less noisy areas,
but obviously not everybody
can afford that.
So what can we do right now
to 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 hard
of hearing are still going to the movies.
If you complain about the noise
and nothing happens,
demand a refund and leave.
That’s the language that managers
typically do understand.
Also, talk to your children
about the health effects of noise
and that listening to loud music today
will have consequences when they’re older.
You can also move your bedroom
to the quiet side of the house,
where your own building shields you
from road traffic noise.
If you’re looking to rent
or buy a new place,
make low noise a priority.
Visit the property during
different times of the day
and talk to the neighbors about noise.
You can wear noise-canceling headphones
when you’re traveling
or if your office has high
background noise levels.
In general, seek out quiet spaces,
especially on the weekend
or when you’re on vacation.
Allow your system to wind down.
I, very appropriately for this talk,
attended a noise conference
in Japan four years ago.
When I returned to the United States
and entered the airport,
a wall of sound hit me.
This tells you that
we don’t realize anymore
the constant degree
of noise pollution we’re exposed to
and how much we could profit
from 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 do
to make that noise footprint smaller.
For example, don’t start mowing your lawn
at 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 source
makes the most sense,
so whenever you’re looking
to buy a new car,
air-conditioning unit,
blender, you name it,
make low noise a priority.
Many manufacturers will list
the noise levels their devices generate,
and some even advertise with them.
Use that information.
Many people think that stronger noise
regulation and enforcement are good ideas,
even obvious solutions, perhaps,
but it’s not as easy as you may think,
because many of the activities
that generate noise
also generate revenue.
Think about an airport and all
the business that is associated with it.
Our research tells politicians
at 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 noise
as 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 have
a nice, quiet celebration.
(Laughter)
Thank you.
(Applause)