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Bio-acoustics Research
We perform
research in atmospheric (in the air), underwater, and seismic bio-acoustics. We
help major zoos, universities, and students with their own research papers, and
conduct our own novel research.
Many times a professor, zoo administrator or
other person, who operates in a different field of science does
not know about how to conduct acoustics research, so they call us. Which is only
logical, we are not paleontologists, so we would contact them with questions.
Likewise a
student (mostly those in a masters or doctoral program) come to us to learn this
branch of science. Bio acoustics is complicated and few places teach it.
If you already know about bio-acoustics and are
looking for a consultation, or to help with a research paper of your own,
please
See our
Consultations Page
or
contact us
Bioacoustics is a branch of science concerned
with the production of sound and its effects on living systems. In particular,
animal communication, deals with the production, meanings (animal linguistics
and cognition), and effects of sounds generated by animals. There are different
ways animals communicate, including scent (pheromones) and by body language.
However the most effective type of communication for most species is sound.
There are many
specializations of animal communication and bioacoustics, the most popular being
the studies of bird song. Please go to the
LINKS
if you are interested in bird song.
There are several ways to
analyze sound, however each vocalization, whether it comes from a human or an
elephant will be described by in frequency and amplitude,
and time.
Frequency
The frequency of a sound or
vocalization is the pitch. In other words a human child's voice will probably be
higher than a human adult. Frequency level is expressed in Hertz or Hz.
A:) Infrasound
Back to the
Earthquake/tsunami/animal page
Infrasounds are sounds below
the human range of hearing, technically 20Hz, but most adults will be hard
pressed to hear anything below 40 Hz. Your average sub-woofer speaker goes down
only to 25-40 Hz. However, at high enough amplitude (very loud) you can feel
infrasound, it will shake you. Anyone that has ever watched the space shuttle
take off will tell you that it shook the ground and rattled windows, that is
infrasound! Infrasound is a long, sound wave. It can pass through forests,
buildings and even mountains. For example, the space shuttle taking off creates
a very loud sound pressure wave of .02Hz (very, very low). It takes @20 minutes
for this sound to reach Langley Air Force Base in Virginia, from Kennedy in
Florida. This sound wave will pass through everything on its way, and will
continue around the earth until it finally dissipates due to attenuation
(lessening of the amplitude of the signal over distance/time). Animals that
generate infrasound include elephants, whales, alligators, hippos, rhinos,
giraffe, lions, okapi, tigers, and several birds. The common thought used to be
that only large animals could generate infrasounds, we now know that smaller
animals do produce infrasound and there are probably many more we do not know
of.The animals that can detect infrasound either seismically (through the
ground), atmospherically (through the air) or underwater, are too numerous to
mention. Fauna Communications specializes in studying this type of sound.
Back to the
Earthquake/tsunami/animal page
B:)
Sonic range
Sonic sounds are within the
range of human hearing, technically 20 to 20,000 Hz. More likely for adults it
is between 40 to 15,000 Hz. Many animals communicate in the sonic range, most
mammals, birds, fish, etc.
C:) Ultrasound
Ultrasounds are sounds that
occur above the range of human hearing, or above 20,000 Hz. Animals that
communicate in this include Dolphins,
bats, many birds and insects. Ultrasounds are short sound waves that bounce off
trees, rocks, etc. This is why bats and dolphin use theses signals for
echolocation, they actually see by how the sound bounces back to them. This is a
fascinating area of sound production, and also one which Fauna Communications is
interested in.
Amplitude
The amplitude of a sound or
vocalization is its loudness. A human whisper will be lower in amplitude than
normal human conversation. Amplitude is normally expressed in decibel level or
dB. A plane taking off will be higher in dB than clapping your hands. A rock
concert usually has amplitudes above 120 dB, where 130 is the threshold for
pain. 120 dB is too loud. If you do not use ear protection at a rock concert,
you are damaging your ears. Once damaged, your hearing will never be the same.
Many rock musicians are deaf because of this.
Amplitudes from 40-70 are considered normal for
human conversation, but many animals use sounds that are louder or quieter. An
elephant produces a sound at 14Hz (infrasound), we cannot hear it but we can
feel it because the amplitude is 90dB, it is loud. A giraffe produces a sound at
14Hz, and we cannot hear it or feel it because
the amplitude is 40dB, it is quiet.
There is much much more to animal communication,
that is simply not possible to write about here. For more information please see
the LINKS page.
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