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Sunday, June 9, 2019

The Wind Turbine Infrasound Noise Problem -- Part 2

I was asked to expand 
my prior article on 

Infrasound occurs 
where large masses 
are in motion, such as 
avalanches and 

Infrasound in industry
can come from 
very large machines, 
such as automotive
sheet metal presses, 
and from dynamite blasting. 

Unfortunately, wind turbines 
also generate infrasound
when their blades rotate. 

Turbines also make 
other annoying noises,
kill lots of birds and bats,
provide expensive electricity,
and intermittent electricity.

They are "total losers",
as President Trump might
have said, compared with
nuclear power.

This long-time 
( since 1965 )
audiophile says 
there's a serious 
infrasound noise 
problem facing 
the leftist dream 
of huge increases
in the numbers 
of wind turbines,
that is being ignored.

Infrasound is defined
as frequencies below 
20 cycles per second,
or 20 Hz.

My extensive experience 
designing, building, testing 
and equalizing subwoofers, 
since the early 1980s,
results in a different 
definition:  Below 30 Hz.

As frequencies decline
below 40 Hz., you will
increasingly FEEL the sound
with your body, more than 
you HEAR it with your ears.

At 30 Hz. what you 
actually "hear"
will mainly be the
harmonic distortion
at 60 Hz. and 90 Hz.,
not the 30 Hz. test tone. 

Rooms inside a home 
have bass resonances
at frequencies related to
the room's dimensions.

The bass resonances
inside rooms are usually
called standing waves,
-- they include 
positive feedbacks
that amplify certain 
low frequencies.

The lowest resonance
frequency in a room 
will be from reflections 
between walls 
of the room's 
largest dimension.

The walls do not 
have to be parallel.

In a larger room, 
one room resonance
is likely to be 
below 30Hz.

For homes 
with a relatively 
large interior 
open space, 
perhaps a kitchen, 
dining room,
and living room, 
the three room area 
can resonate at a 
specific frequency -- 
likely to be in the 
infrasonic range. 

The whole house,
if made of wood,
can resonante 
at one specific

As a result, 
measuring outdoors, 
where the measurements 
usually take place, can be 
very deceptive.

The noise inside a room
can be FAR MORE annoying 
than outside the home.

Low frequencies 
the home 
can excite 
one or more 
standing waves 
inside a room, 
amplifying the
exterior noise 

This could be more 
annoying if outdoors
infrasound was
a pulsing sound,
like the sound from 
a wind turbine.

I've had a ridiculous amount
of experience with infrasound 
frequencies inside a home, 
from the mid-1980s 
to the mid-1990s,
as part of a southeastern 
Michigan audio club, where 
building self-designed 
subwoofers was encouraged.

With these monster subwoofers,
club members soon found out 
few compact discs had the
deep bass and infrasound 
they wanted to show off 
their great designs.

Audio consultant Dave Clark's
company measured and found
a few CDs with ultra low bass
so club members could show off
their do it yourself subwoofers.

During one audio club meeting, 
I was driven out of a home
by infrasound from the biggest
displacement subwoofer 
designed by any
audio club member, using 
twelve 15" bass drivers, 
shown in the picture below:

An earlier version, with 'only'
eight 15" bass drivers, was described
in a 1999 audio magazine article as: 
"The Subwoofer That Shook The World".

I don't think audio consultant
Tom Nousaine would have 
appreciated me responding 
to his subwoofer by throwing up 
inside his large listening room !

So I rushed outside, feeling weak 
and nauseous, from my internal 
organs getting "all shook up".

A few other audiophiles 
had moved outside too,
and we were surprised
the loud bass / infrasound
did not seem to affect 
the other club members.

We all had experienece with 
deep bass, but not with
high energy infrasound.

While outside, a few of us 
began wondering if
infrasound could ever be 
used as a military weapon. 

But we knew deep bass, 
especially infrasound,
is omnidirectional 
-- so we had no idea 
how you could aim it 
at the enemy, without 
harming your own troops.

And it seemed that most people 
in the club were able to tolerate 
infrasound energy, at least 
as part of "music", which 
added up to a not very 
effective military weapon. 

Colonel John B. Alexander,
headed a department that
developed unorthodox weapons,
including an infrasound weapon:

Colonel Alexander said this
about an experimental
infrasound weapon, 
after it was rejected:
"There were some people 
who were physiologically 
affected. They were nauseous. 
They would get dizzy." 

"There were some who had 
psychological issues, fear 
factors, inability to think, 
kinds of things".

"We found that some people 
are affected dramatically. 

"Some people are affected 
a little bit, and others not at all." 

"From a weapons perspective
... ( we need to ) know exactly 
what the effects are going to be."

The US military gave up 
on an infrasound weapon
after 2000, because 
its effects on people 
were too random: 
  Some targets were 
seriously debilitated; 
others not much. 

Just like my own experience
during that audio club meeting !

"Wind farms" have existed 
for more than two decades.

Germans know a lot about 
wind turbine noise problems,
because they have 30,000+
industrial wind turbines !

Some of their wind farms 
border on residential areas, 
and some people there 
are having trouble sleeping.

It took a long time 
for people to realize 
their health problems 
were being caused
by wind turbine noise. 

Doctors believe between 
10% and 30% of people react 
negatively to infrasound.

Problems include Insomnia, 
heart problems, perception 
disorders, and dizziness.

Germany’s Max Planck Institute 
identified sub-audible infrasound 
as the cause of stress, sleep 
disruption and more.

A Swedish group showed 
the pulsing nature of 
the low-frequency 
wind turbine noise  
( ‘amplitude modulation’ ) 
was responsible 
for sleep problems.

In Germany, 
health problems 
ramped up a lot after
small, old turbines
were replaced with 
bigger, more efficient 
models, a change 
promoted by the German 
Environment Agency.

But German officials 
were not concerned about 
infrasound coming
from wind farms -- 
they claimed that
beyond 700 meters,
the wind turbine 
infrasound noise 
was drowned out 
by other outside
sources of
infrasound noise. 

I'm confident 
that conclusion 
was caused by 
two errors:
The great difficulty of measuring 
outdoor infrasound with conventional
sound measurement equipment, and

What matters much more 
is what people hear inside 
their homes, where they spend 
most of their time, and where
they try to sleep eight hours
a day.

The Federal Institute 
for Geosciences and 
Natural Resources ( the BGR ), 
operates a measuring station, 
called the I26DE, for the 
German government.

I26DE is part of an international 
monitoring network designed 
to ensure that terms 
of the nuclear test ban treaty 
are observed. 

They measure infrasound 
very close to the ground, 
because wind noise can trick 
any measurement device.

Their measurement system 
is a few meters underground,
using garden hoses to conduct
the infrasound signals from 
the various inlets, to a 
very sensitive micro-barometer.

A problem developed:
Infrasound from wind farms 
could affect measurements 
taken by the I26DE Station,
so in 2004 the BGR 
decided to measure the
infrasound emissions 
from a single wind turbine. 

Every time the
wind turbine blade 
passed the tower, 
large air volumes 
were compressed
and sheared. 

This signal produced 
an infrasound signature 
called: "blade pass 

The blade pass harmonics 
clearly emerge from 
outdoor background noise, 
with a higher acoustic 
pressure level. 

The wind turbine 
studied in 2004 
was very small unit, 
barely 0.2 megawatts. 

For bigger wind farms, 
the scientists developed 
a model for calculations.

Their model says that
a five megawatt wind turbine, 
could generate a detectable 
infrasound signal from a 
distance of 20 kilometers !

20 kilometers is MUCH longer 
than the German Environment
Agency claimed -- they said 
the infrasound emissions 
from wind energy plants, 
were lost in the background noise, 
at a distance beyond 700 meters !

The huge difference is 
from measuring broad bands 
of frequencies, rather than 
individual frequencies
that would clearly capture 
the specific blade pass 
harmonic frequencies.

The broad frequency bands 
obscured the power of the 
specific blade pass harmonics.

Mr. Oldewurtel lives
700 meters from 
a Finnish wind farm, 
with a few dozen 
wind turbines
that function even 
at low wind speeds.

Oldewurtel said: 
"If you sleep here 
for four or five days, 
you feel like you’ve 
been out drinking 
for a whole week." 

"It’s that bad." 

"You get those total 
mental blank outs." 

"It’s even happened 
to me on the phone." 

"I couldn’t believe it, 
but if I’m out and about, 
or if I go away for a few days, 
I’m as right as rain again."

Oldewurtel commissioned 
measurements by expert 
Sven Johannsen,
after the government 
refused to do measurements.

Johannsen used microphones 
and vibration sensors to measure 
the home's interior and exterior. 

And a micro-barometer to record
minute air pressure fluctuations.

His measurements showed 
powerful home vibrations, and 
extremely high infrasound levels 
inside the home -- even higher
acoustic pressure levels 
than measured outside the home !

A noise survey done 
by the government 
perhaps using something
like the DIN 45680 
( the German Standard ),
would have ignored 
infrasound frequencies.

I was stunned by the studies
showing how many miles 
wind turbine infrasound 
can travel.

I had expected no more 
than one mile / 1.5 kilometers.

Infrasound should travel 
in all directions
( omnidirectional )
from a wind turbine, 
not just down wind.

The Finns have found
the safe setback distance 
from wind farms to homes 
is 15,000 meters, not the 
1,000 meters planning rules 
typically permit.

A team of German researchers 
tried to find out what their fellow 
countrymen are being exposed to
at distances of over 20 kilometers !

Government rules 
to use a lot more 
"renewable" energy
in the future, 
are overwhelming  
the "little people" 
suffering negative 
side effects from 
the noise, especially 
from infrasound noise.

But then ...
Why should governments care
about infrasound, that no one can
hear with their ears, when they
don't care about the high cost 
of wind generated electricity, 
or its intermittent electricity 
output !

From a translation of the
Finnish Association for 
Environmental Health (SYTe) 
study in spring 2016:

The damage caused by 
infrasound from 
wind power plants will only 
decrease significantly 
more than 15 kilometers 
away from wind turbines !

The data were collected 
from Satakunta and 
Northern Ostrobothnia, 
mainly from areas 
where wind turbines 
were built 0.5 to 1.5 years 
before the interview.

Fifty families, 
with about 200 people,
were studied.

The basic research question 
was whether the family 
had noticed changes in health 
status in the last six months 
to a year. 

Interviewees were NOT 
told in advance about the 
possible connection 
with wind turbines.

Most respondents 
were unable to name 
a change in their 
overall health status. 

But there were 
many mentions of
sleep disturbance, 
changes in the need 
for more sleep, fatigue 
and various pains. 

Few respondents 
had ever considered 
the wind turbines 
as a possible cause.

Harmful or severe 
health symptoms 
were three times 
more common 
near wind turbines.

Symptoms decreased 
significantly only over 
15 to  20 kilometers
from the wind 
power plants !

After the construction 
of wind power plants, 
the majority of people 
in the nearby vicinity
are having symptoms, 
mainly related to stress.

In 2017, 
additional infrasound 
made in different 
parts of Finland, 
found out that
15 to 20 kilometers
is a typical maximum 
distance where the 
infrasound pulses 
of wind turbines 
could be measured.