By Jonathan Amos
BBC News Online science staff, in Salford

(INFRASOUND STUDY: Lies in the range 10-20 Hz. On the
cusp of our
hearing.
Can vibrate internal organs, volcanoes emit
infrasound. Elephants and
whales
use it.)

People who experience a sense of spirituality in
church may be reacting
to
the extreme bass sound produced by some organ pipes.

Many churches and cathedrals have organ pipes that are
so long they
emit
infrasound which at a frequency lower than 20 Hertz is
largely
inaudible to
the human ear.

But in a controlled experiment in which infrasound was
pumped into a
concert
hall, UK scientists found they could instil strange
feelings in the
audience
at will.

These included an extreme sense of sorrow, coldness,
anxiety and even
shivers down the spine.

Infrasound has become the subject of intense study in
recent years.
Researchers have found that some animals, such as
elephants, can
communicate
with low-frequency calls.

Infrasound can be detected at volcanoes and may
provide a way to
predict
eruptions.

And recent work by some of the scientists involved in
this latest study
found that hauntings - the feeling that something or
someone else
unseen is
in a room or building - may also be explained by the
presence of
infrasound.

To test the impact on an audience of extreme bass
notes from an organ
pipe,
researchers constructed a seven-metre-long "infrasonic
cannon" which
they
placed at the back of the Purcell Room, a concert hall
in South London.

They then invited 750 people to report their feelings
after listening
to
pieces of contemporary music intermittently laced
sound from the
cannon,
played a 17 Hz at levels of 6-8 decibels.

FEEL THE BASS

The results showed that odd sensations in the audience
increased by an
average of 22% when the extreme bass was present.

"It has been suggested that because some organ pipes
in churches and
cathedrals produce infrasound this could lead to
people having weird
experiences which they attribute to God," said
Professor Richard
Wiseman, a
psychologist from University of Hertfordshire.

The pipe put out sound at 17 Hz "Some of the
experiences in our
audience
included 'shivering on my wrist', 'an odd feeling in
my stomach',
'increased
heart rate', 'feeling very anxious', and 'a sudden
memory of emotional
loss'.

"This was an experiment done under controlled
conditions and it shows
infrasound does have an impact, and that has
implications... in a
religious
context and some of the unusual experiences people may
be having in
certain
churches."

Sarah Angliss, an engineer and composer in charge of
the project,
added:
"Organ players have been adding infrasound to the mix
for 500 years so
maybe
we're not the first generation to be 'addicted to
bass'."

Details of the organ infrasound study are being
presented to the
British
Association's annual science festival, which this year
is in Salford,
Greater Manchester.