Hearing

1. BulletsSeveral witnesses have responded to an approaching UFO in the manner of the Old West, that is, by drawing abead and firing with a rifle or pistol. The bullets have been heard to strike metallic surfaces and whine off in2ricochets. Also, the landing of nearby UFOs has been heard as a thud such as would be expected from a not-so-3gentle setdown of a ponderous machine. While these sounds offer no clues to the UFO fields, they suggest that theobjects under study are not imaginary, vaporous, holograms, ball lightning, or earthquake lights.4A 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. ViolentVery early in the morning of September 30, 1980, near Sale, Southern Australia, George Blackwell awoke to awhistling sound. It came from a wingless craft 8 m. across that displayed colored lights as it spun. It flew slowly atlow altitude, finally settling to the ground near a large water tank. The witness approached to within 15 m. when thewhistling sound became very loud. Then he heard an awful bang, accompanied by a blast of air and heat as the5, 8object 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 wasearly morning on a wintry day. Suddenly, the object became surrounded by a mist. Then a brilliant glow appeared asthe object rose off the ground. A few seconds later, he heard an explosion as the UFO departed. The sound wasclearly a shock wave from the UFO as the time delay was appropriate for the distance and the speed of sound.2Effects of UFOs Upon PeopleExplanationShock waves appear to be generated only at take-off. While sitting on the ground, the propulsion system ispresumed to be turned off; that is, no external field surrounds the UFO. Power would then be required to initiate thefield. The sudden appearance of mist in the San Joaquin case is a vital detail. That region in California is noted forvery dense, ground fogs resulting from ground cooling due to radiant heat loss to the cosmos during long winternights and high humidity near sloughs and swamps. Water vapor adjacent to the UFO could have been condensed bya reduction either in temperature or pressure. Because the phenomenon was accompanied by a shock wave, a changein temperature alone can be ruled out. The newly generated field must have exerted an outward force on theatmosphere, thereby reducing the pressure close to the surface. A very small pressure change, indeed, would sufficeto cross the dew point and condense water vapor from saturated air at 100% humidity. Such condensation cansometimes be observed in the low-pressure zone above airplane wings. Again microwaves emanating from UFOsare suspected because, at certain wavelengths, they are resonantly absorbed by water molecules with anaccompanying transfer of momentum, that is, a force. Resonances are at wavelengths of 0.17 cm. with four strongerones below 0.1 cm. Continuation of the process of pushing the air out of the way is the likely reason that UFOs can6fly faster than the speed of sound without creating sonic booms. 3. TonesThe most prevalent types of sounds are either low or high pitch. Words used by witnesses often succinctly andspecifically denote the pitch. For example, the former might be approximated by a hummingbird, the latter likenedto the squeal between stations on old-fashioned AM radios. Two revealing cases have recently come to light afterbeing 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 thatwas increasing in apparent size. As it came closer, it was seen as a circular plate giving off a dazzling white lightand leaving a white trail. During a two- to three-minute observation, it flew over the frightened observers at1000 m., producing a whistling sound that was louder than a jet. As the object approached the witnesses, the low7pitch 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 in1983 under a lawsuit pursuant to the Freedom of Information Act. Two fiery objects glided in sweeping curves overuranium mines. They were seen in several perspectives as disks, ovals, and thin lines. During 10 to 12 minutes ofobservation, they emitted hissing and buzzing sounds. Commander Pierre at a small airfield jumped into a fighterplane and took off in pursuit. He was able to get within 150 m. of the objects that were disk-shaped, aluminum, 12 to15 m. in diameter, with a rim of fire. They were emitting a whistling sound that could easily be heard over theairplane engine. Note that the sound changed from low pitch to high pitch as the witness approached the objects,8without mention of intermediate tones. In both cases, the range closed, with movement of the object in China andof the witness in the Congo.ExplanationIt has long been recognized that people can hear electromagnetic radiation in the microwave region, such asradar and microwave radiation from UFOs was suspected as the cause of humming sounds. Relatively little wasknown about this phenomenon 15 years ago, but it had been well established that the aural response was caused byshort bursts of energy corresponding to pulsation of the microwave source. In some uncertain manner, the pulsesstimulated the organ in the inner ear that sends signals to the brain. The tonal value perceived by experimentalsubjects corresponded to the pulse rage of the source. Also, the location of the source was usually thought to bebehind the head as the direct response of microwave bypassed the time delay of ordinary, slow-moving sound wavesreaching the more remote ear. This process, known as binaural audition, is one of several clues to recognizing thedirection from which sounds originate. Vigorous research during the 1970s brought this highly complex9phenomenon into sharp focus. But for the present purpose, many details must be omitted so some statements are 3James McCampbellsubject to various technical restrictions that are not mentioned. Generally speaking, it has been shownexperimentally that people are able to hear pulsed microwaves from 200 to 3,000 MHz with peak power densities of2 2300 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.2In 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 5times 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 highpitch sounds. Absorption of energy in biological tissue produces an extremely small increase in temperature. Due tothermal expansion of the tissue, a corresponding increase in pressure is produced that then propagates through themedium as a sound wave. A microwave pulse impinging upon the head thereby creates a pressure wave thatpropagates through the skin, muscle, bone, and brain tissue and reverberates inside the cranium. These vibrations arecarried by bone conduction to register as sound in the auditory nerve. Microprobes have been surgically implantedin the auditory nerves of animals to measure the frequencies of pulses stimulated by this mechanism. It has beenfound that the frequency depends only upon the size of the head and the acoustical properties of brain tissue. Anextremely intricate, theoretical analysis by Dr. James C. Lin accurately duplicates the experimental data for guinea10pigs and cats. For example, the calculated frequency for cats ranged from 30 to 40 kHz, whereas the measuredvalue was 38 kHz. The measured value for cats is within their normal hearing range, up to 60 kHz, but well beyond2the 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 theoretical2models expected to yield upper and lower limits. The calculated threshold for man, 2183 mW/cm, is extremely high2compared to safety limits in the U.S. for short-term exposure of only 10 mW/cm. Anyone hearing a shrill whistlefrom a UFO would be in serious danger.Thus, experiment and theory show that the pitch perceived from impinging microwave pulses result from twodistinctly different mechanisms. At weak intensities and pulse rates in the low audio range, the pulses directlystimulate the inner ear and are interpreted as humming sounds. For very intensive radiation pulses, pressure wavesreverberate inside the head creating the impression of high pitch whistles. No known mechanism produces tones ofintermediate frequencies. Thus, the sounds stimulated by microwave radiation from UFOs would be discontinuously11dependent upon the distance to the UFO.