HEARING

1. Bullets
Several witnesses have responded to an approaching UFO in the manner of the Old West, that is, by drawing a
bead and firing with a rifle or pistol. The bullets have been heard to strike metallic surfaces and whine off in
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ricochets. Also, the landing of nearby UFOs has been heard as a thud such as would be expected from a not-so-
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gentle setdown of a ponderous machine. While these sounds offer no clues to the UFO fields, they suggest that the
objects under study are not imaginary, vaporous, holograms, ball lightning, or earthquake lights.
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A survey of close encounter cases by the author classified five distinct types of sounds emanating from UFOs.
They were:
VIOLENT (roar, explosion)
LOW PITCH (hum, buzz)
RUSH OF AIR (whoosh, swish)
HIGH PITCH (shrill, whistle)
SIGNALS (beeps, pulses)
2. Violent
Very early in the morning of September 30, 1980, near Sale, Southern Australia, George Blackwell awoke to a
whistling sound. It came from a wingless craft 8 m. across that displayed colored lights as it spun. It flew slowly at
low altitude, finally settling to the ground near a large water tank. The witness approached to within 15 m. when the
whistling sound became very loud. Then he heard an awful bang, accompanied by a blast of air and heat as the
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object took off vertically and flew away.
A highway patrolman saw a strange object sitting on the ground in the San Joaquin Valley of California. It was
early morning on a wintry day. Suddenly, the object became surrounded by a mist. Then a brilliant glow appeared as
the object rose off the ground. A few seconds later, he heard an explosion as the UFO departed. The sound was
clearly a shock wave from the UFO as the time delay was appropriate for the distance and the speed of sound.
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Effects of UFOs Upon People
Explanation
Shock waves appear to be generated only at take-off. While sitting on the ground, the propulsion system is
presumed to be turned off; that is, no external field surrounds the UFO. Power would then be required to initiate the
field. The sudden appearance of mist in the San Joaquin case is a vital detail. That region in California is noted for
very dense, ground fogs resulting from ground cooling due to radiant heat loss to the cosmos during long winter
nights and high humidity near sloughs and swamps. Water vapor adjacent to the UFO could have been condensed by
a reduction either in temperature or pressure. Because the phenomenon was accompanied by a shock wave, a change
in temperature alone can be ruled out. The newly generated field must have exerted an outward force on the
atmosphere, thereby reducing the pressure close to the surface. A very small pressure change, indeed, would suffice
to cross the dew point and condense water vapor from saturated air at 100% humidity. Such condensation can
sometimes be observed in the low-pressure zone above airplane wings. Again microwaves emanating from UFOs
are suspected because, at certain wavelengths, they are resonantly absorbed by water molecules with an
accompanying transfer of momentum, that is, a force. Resonances are at wavelengths of 0.17 cm. with four stronger
ones below 0.1 cm. Continuation of the process of pushing the air out of the way is the likely reason that UFOs can
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fly faster than the speed of sound without creating sonic booms.
3. Tones
The most prevalent types of sounds are either low or high pitch. Words used by witnesses often succinctly and
specifically denote the pitch. For example, the former might be approximated by a hummingbird, the latter likened
to the squeal between stations on old-fashioned AM radios. Two revealing cases have recently come to light after
being hidden for decades:
At 4:00 a.m. on July 25, 1957, several workers were taking a break at the Daye Steel Plant in Huangshi City,
Peoples Republic of China. Upon hearing a humming sound, they noticed a bright spot in the clear night sky that
was increasing in apparent size. As it came closer, it was seen as a circular plate giving off a dazzling white light
and leaving a white trail. During a two- to three-minute observation, it flew over the frightened observers at
1000 m., producing a whistling sound that was louder than a jet. As the object approached the witnesses, the low
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pitch changed to high pitch; no mention was made of any intermediate tones.
The next example, collected by the CIA in southern Belgian Congo in 1952, remained secret until released in
1983 under a lawsuit pursuant to the Freedom of Information Act. Two fiery objects glided in sweeping curves over
uranium mines. They were seen in several perspectives as disks, ovals, and thin lines. During 10 to 12 minutes of
observation, they emitted hissing and buzzing sounds. Commander Pierre at a small airfield jumped into a fighter
plane and took off in pursuit. He was able to get within 150 m. of the objects that were disk-shaped, aluminum, 12 to
15 m. in diameter, with a rim of fire. They were emitting a whistling sound that could easily be heard over the
airplane engine. Note that the sound changed from low pitch to high pitch as the witness approached the objects,
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without mention of intermediate tones. In both cases, the range closed, with movement of the object in China and
of the witness in the Congo.
Explanation
It has long been recognized that people can hear electromagnetic radiation in the microwave region, such as
radar and microwave radiation from UFOs was suspected as the cause of humming sounds. Relatively little was
known about this phenomenon 15 years ago, but it had been well established that the aural response was caused by
short bursts of energy corresponding to pulsation of the microwave source. In some uncertain manner, the pulses
stimulated the organ in the inner ear that sends signals to the brain. The tonal value perceived by experimental
subjects corresponded to the pulse rage of the source. Also, the location of the source was usually thought to be
behind the head as the direct response of microwave bypassed the time delay of ordinary, slow-moving sound waves
reaching the more remote ear. This process, known as binaural audition, is one of several clues to recognizing the
direction from which sounds originate. Vigorous research during the 1970s brought this highly complex
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phenomenon into sharp focus. But for the present purpose, many details must be omitted so some statements are
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James McCampbell
subject to various technical restrictions that are not mentioned. Generally speaking, it has been shown
experimentally that people are able to hear pulsed microwaves from 200 to 3,000 MHz with peak power densities of
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300 mW/cm and average power densities as low as 0.4 mW/cm with pulse widths of 1 to 100 microseconds (msec).
As the shape of the response curve is a steep-sided mesa, the range of pulse width is probably about 10 to 40 msec.
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In terms of average power density, the threshold is approximately 120 mW/cm . Therefore, very low-intensity,
microwave radiation pulsed at 50 to 100 cycles per second would be “heard” and aptly described as humming.
Experiments with animals showed that cats were 20 to 30% more sensitive than people, but one dog tested was 5
times more sensitive. That result may explain why agitated dogs are the first indication of many UFO events.
An entirely different mechanism, known as the thermoplastic process, appears to be responsible for the high
pitch sounds. Absorption of energy in biological tissue produces an extremely small increase in temperature. Due to
thermal expansion of the tissue, a corresponding increase in pressure is produced that then propagates through the
medium as a sound wave. A microwave pulse impinging upon the head thereby creates a pressure wave that
propagates through the skin, muscle, bone, and brain tissue and reverberates inside the cranium. These vibrations are
carried by bone conduction to register as sound in the auditory nerve. Microprobes have been surgically implanted
in the auditory nerves of animals to measure the frequencies of pulses stimulated by this mechanism. It has been
found that the frequency depends only upon the size of the head and the acoustical properties of brain tissue. An
extremely intricate, theoretical analysis by Dr. James C. Lin accurately duplicates the experimental data for guinea
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pigs and cats. For example, the calculated frequency for cats ranged from 30 to 40 kHz, whereas the measured
value was 38 kHz. The measured value for cats is within their normal hearing range, up to 60 kHz, but well beyond
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the limit of human hearing at 20 kHz. The calculated threshold for cats was 589 mW/cm for a head radius of 3 cm.
For a man with a head radius of 7 cm., the calculated frequency range from 10 to 15 kHz based upon theoretical
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models expected to yield upper and lower limits. The calculated threshold for man, 2183 mW/cm , is extremely high
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compared to safety limits in the U.S. for short-term exposure of only 10 mW/cm . Anyone hearing a shrill whistle
from a UFO would be in serious danger.
Thus, experiment and theory show that the pitch perceived from impinging microwave pulses result from two
distinctly different mechanisms. At weak intensities and pulse rates in the low audio range, the pulses directly
stimulate the inner ear and are interpreted as humming sounds. For very intensive radiation pulses, pressure waves
reverberate inside the head creating the impression of high pitch whistles. No known mechanism produces tones of
intermediate frequencies. Thus, the sounds stimulated by microwave radiation from UFOs would be discontinuously
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dependent upon the distance to the UFO.