As an audiophile since 1965,
who has built many do-it-yourself
subwoofers since the 1980's,
I have always been interested
in bass and infrasound.
So interested, that in my first year
of engineering school, at the Rochester
Institutute of Technology, the only thing
I remember today is our infamous
"speaker experiment".
One budding engineer had a pair of huge
homemade speakers with 15" bass drivers,
whose bass was extended with tuned ports,
considered state of the art at the time.
Listening to music in a small dorm room,
we found that certain frequencies of
bass caused our chest cavities to resonate.
So we borrowed a tone generator, and did
experiments, fueled by beer, with coeds
as our subjects.
We found out that chest cavities resonated
between 75 and 150 Hz. (cycles per second)
depending on the size of the subject
-- an uncomfortable feeling,
and a few coed subjects objected
to the "science" of having
their chests "resonated" .
Loud bass tones between 40 and 80 Hz.
would not resonate the chest cavity,
but would cause stomach discomfort.
What we would could not experiment with
at the time, was infrasound -- under 20 Hz.
However, two subwoofers I built,
six cubic foot monsters located
in my living room, can play clean
signal tones in the 15 to 25 Hz. range,
where bass frequencies are felt,
much more than heard.
Fortunately, there's not much music
below 25 Hz., because loud test tones
at those frequencies create discomfort
in just 10 to 20 seconds.
Noise is a big problem
with wind turbines.
More than just the audible sound -- also
the infrasound -- which travels a long way.
Wind projects in rural areas
may be near homes.
So there's no escape from discomfort,
and annoyance, beyond moving.
Typical symptoms are Insomnia, dizziness,
heart problems, and perception disorders.
Regulations of audible noise
almost always use sound
pressure meters
operating on the
A-Weighting scale (dBA).
That dBA scale assumes
hearing damage is mainly
from frequencies above 1,000 Hz.,
so it rolls off the measurements
a lot as frequencies decline
below 1,000 Hz, meaning it
"discriminates against"
bass frequencies.
When I am setting
my parametric equalizer
for my subwoofers,
I have to use the
"flat" C-weighted scale (dBC)
for my sound pressure meter.
The C-Weighting
captures all the bass.
while the A-Weighting does not.
So a 40 dBA (averaged) daytime
sound pressure limit
( aka "volume" ),
as a local regulation, or a
nighttime limit of 35 dBA,
means VERY LITTLE
for bass frequencies,
especially for infrasound
frequencies.
The description
of the sound impacts
of wind mills as “torture,”
by people living nearby,
has been repeated
across the world.
The industry covers it's back
with a $2.1 million dollar study
from Canada ( the Health Canada
Wind Turbine Study ), and the
Massachusetts Impact Study.
But a more recent Finnish study
found that infrasound (IS)
showed no significant reduction
in damage until over 15 kilometers
from wind farms !
That's really surprising
-- I would have guessed
1.5 kilometers, not 15.
The study was carried out by the
Finnish Association for Environmental
Health (SYTe), in spring 2016.
" ... after the construction of wind
power plants, usually within a few months,
people in the surrounding area have begun
to get a wide range of symptoms."
says Markku Mehtätalo, Chairman of the
Finnish Association for Environmental Health.
Low-frequency sounds (including sounds
in the infrasound frequency spectrum)
can cause high levels of annoyance
and distress.
IS promoted more severe medical symptoms,
ranging from sleep disturbances, headache
and dizziness, to panic attacks and depression.
Infrasound Victim Insa Block:
"After five or 10 minutes,
I feel kind of dizzy."
"My heart starts to race and
I get this massive ringing
in my ears. "
"To some extent, I also feel
claustrophobic and stressed."
"When I was lying in bed,
I actually noticed the
vibrations on the mattress."
"I had this strange feeling
that something was wrong."
"Then in the half-light,
I clearly saw the mattress
move several centimeters.".
" When the buzzing starts,
it’s like you are in a beehive.
"You just need to put your hand
on the wall of the house,
and feel the vibrations ... "
Insa Bock
lives in East Frisia,
near the town of Esens,
located about 700 meters
from her home is a "wind farm"
with a few dozen wind turbines.
Since they function
even at low wind speeds,
that wind farm is in
operation virtually 24-7.
Professor Alec Salt
from the Washington
School of Medicine,
in St Louis, is an
internationally recognized
expert on the physiology
of the inner ear.
"We discovered that
if you went down to
very, very low frequencies ...
we discovered even 5 hertz
was getting lovely results."
"When a human is exposed
to infrasound, that sound
is going to go into their ear. "
" ... They don’t hear the sound at all,
but there’s still electrical responses
in the ear, to the sound."
Professor Simone Kühn
and her colleagues
had exposed test persons
to brief infrasound signals
below the auditory threshold:
"What was interesting to note
was that conditions with infrasound
exposure, close to the auditory
threshold are somehow special."
"Intense activity took place
in the anterior cingulum,
a region of the brain which
deals primarily
with conflict situations,
and also in the right amygdala,
the region which is linked
to stress management ... "
Professor Christian-Freidrich Vahl
is Director of Cardiac, Thoracic
and Vascular Surgery at
Mainz University Medical Centre.
Over the last two years,
he and his team have devoted
their research to the subject
of infrasound.
The researchers are studying
human heart muscle fibers.
Two fibers from the same patient
are isolated -- the specimens
are still alive.
One will serve as a control,
the other will be exposed
to infrasound in the form
of a 16 Hz. frequency
for one hour.
Christian-Friedrich Vahl:
"We can definitely say
that under these
acute conditions,
infrasound really
does have
a distinct effect on
heart muscle tissue."
"Both series of tests
have revealed a clear
reduction in heart muscle
strength."
"Whether we hear it or not,
every form of energy has
physical effects, and infrasound
is particularly dangerous,
because we don’t hear it."
The global wind industry has
systematically sought to silence
wind turbine hosts and neighbors
with property buy-outs and
non-disclosure agreements.
Something is
wrong here,
and not getting
proper attention.
Source of quotes: