The use of sonic weapons underwater has been widely speculated
about.
Some common bio-effects of electromagnetic or other non-lethal
weapons include effects to the human central nervous system
resulting in physical pain, difficulty breathing, vertigo, nausea,
disorientation, or other systemic discomfort. Interference with
breathing poses the most significant, potentially lethal results.
Light and repetitive visual signals can induce epileptic seizures
(see Bucha effect). Vection and motion
sickness can also occur. Cavitation, which affects gas nuclei
in human tissue, and heating can result from exposure to ultrasound
and can cause damage to tissue and organs.
Studies have found that exposure to high intensity ultrasound at frequencies from 700 kHz
to 3.6 MHz can cause lung and intestinal damage in mice. Heart rate
patterns following vibroacoustic stimulation has resulted in
serious negative consequences such as arterial flutter and
bradycardia.
[8]
[9]
Researchers have concluded that generating pain through the
auditory system using high intensity sound resulted in a high risk
of permanent hearing damage. Organizations in a research program
which included the
Naval Submarine Medical Research
Laboratory (Groton, Connecticut), Navy Experimental Diving
Unit (Panama City, Florida), SCC San Diego,
Navy Medical Research and
Development Command (Bethesda, Maryland), Underwater Sound Reference
Detachment of Naval Undersea Warfare Center (Orlando, Florida), Applied Research
Laboratories:
University of Texas at Austin,
Applied Physics Laboratory:
University of Washington, Institute for Sensory
Research:
Syracuse University,
Georgia Institute of Technology, Emory University, Boston University, University of Vermont,
Applied Physics Laboratory,
Johns Hopkins University,
Jet Propulsion Laboratory, University of Rochester, University of Minnesota, University of Illinois,
Loyola University, and
the State University of New York
at Buffalo, involved high intensity audible sound
experiments on human subjects.
The extra-aural (unrelated to hearing) bioeffects on various
internal organs and the central nervous system included auditory
shifts, vibrotactile sensitivity change, muscle contraction,
cardiovascular function change, central nervous system effects,
vestibular (inner ear) effects, and chest wall/lung tissue effects.
Researchers found that low frequency sonar exposure could result in
significant cavitations, hypothermia, and tissue shearing. No
follow on experiments were recommended. Tests performed on mice
show the threshold for both lung and liver damage occurs at about
184 dB. Damage increases rapidly as intensity is increased.
Noise-induced neurologic disturbances in humans exposed to
continuous low frequency tones for durations longer than 15 minutes
has involved in some cases the development of immediate and long
term problems affecting brain tissue. The symptoms resembled those
of individuals who had suffered minor head injuries. One theory for
a causal mechanism is that the prolonged sound exposure resulted in
enough mechanical strain to brain tissue to induce an
encephalopathy.[10]
“Project Pandora” conducted by the Walter Reed Army Institute of
Research, WRAIR, included externally induced auditory input from
pulsed microwave audiograms of words or oral sounds which create
the effect of hearing voices that are not a part of the recipients
own thought processes.