106 Sentences With "infrasonic" | Random Sentence Generator

Infrasonic devices Infrasound doesn't need to be heard for it to work.

After digging through decades of literature in the field, Jauchem concluded that infrasonic weapons are impractical.

The rumbles of earthquakes, which are too low pitched for us to hear, fall in the infrasonic range.

These devices usually operate at the ultrasonic level (above audible range) or the infrasonic level (below audible range).

That's because they usually operate at the ultrasonic level — above audible range — or the infrasonic level, below audible range.

Using NASA-provided sound-boosting technology, his team gathered data that helped prove okapis communicate via infrasonic noises imperceptible to humans.

His own experiments showed that two minipigs weren't put off their cracked corn during stints in a chamber resonating with infrasonic waves.

Scientists have discovered that they can use infrasonic rumbles (at frequencies below the human hearing range) to communicate for very long distances.

Since the 1990s, the US military and private companies researched infrasonic devices that could cause behavior changes at frequencies too low to be audible.

SATAN is equipped to detect vibrations in the ground and air at very low frequencies, transient magnetic fields, as well as infrasonic and seismic activity.

The second explosion was detected only by infrasonic air pressure sensors and not by the seismic monitors that pick up movements in the ground, she added.

There are also infrasonic frequencies embedded in the back cavity to allow for crystal clear bass, and they're capable of absorbing unwanted feedback for an optimal acoustic environment.

The second explosion was detected by infrasonic air pressure sensors in the Norwegian town of Bardufoss, but further analysis, taking in additional data from Norway and Finland, pointed to a different explanation, Norsar said on its website.

Roomba knew Kaskil's body-language, recognized many words and gestures, and likewise could signal his feelings and opinions with a nod or trunk swing, a trumpet or harrumph, or the thrumming infrasonic rumbles that Kaskil's phone registered as pictographs or emojis.

Frequencies above and below the audible range are called "ultrasonic" and "infrasonic", respectively.

Fighting elephants may roar or squeal, and wounded ones may bellow.Kingdon, p. 63. Rumbles are produced during mild arousal and some appear to be infrasonic. These calls occur at frequencies less than 20 Hz. Infrasonic calls are important, particularly for long-distance communication, in both Asian and African elephants.

Other animal early warning systems may rely on an ability to sense infrasonic waves traveling through the air.

His interest in infrasonic waves first came about in his laboratory during the 1960s, when he and his laboratory assistants experienced shaking laboratory equipment and pain in the eardrums, but his microphones did not detect audible sound. He concluded it was infrasound caused by a large fan and duct system, and soon got to work preparing tests in the laboratories. One of his experiments was an infrasonic whistle, an oversized organ pipe.

BOP Studios was the first recording facility to be equipped with infrasonic monitoring designed by Kinoshita. The acoustic design and building construction were specially made to produce infrasonic energy across a wide frequency spectrum, giving the space an unmatched sound. Tom Hidley and Tom Rast were responsible for the architecture of the studios, which are equipped with custom-made monitors. The consoles in each of the three control rooms are custom built, including a Neve, SSL, and Focusrite.

Some less commonly-used bass enclosures are variants of the subwoofer enclosure's normal range, such as the mid-bass cabinet (60–160 Hz) and the infrasonic (extra low) subwoofer (below 30 Hz).

Because there were so many different sources of infrasound, methods of detecting were of interest for the military and civilians. Long distance propagation of infrasound is allowed by ground reflection and molecular attenuation. The ground acts as a reflecting service for incoming energy and molecular attenuation is zero at infrasonic frequencies. The infrasonic sensing array contained a minimum variance distortion-less response beam former to enhance the detection and estimation performance of the acoustic system by improving the signal to noise ratio.

Long period ground motion is ground movement during an earthquake with a period longer than 1 second. The frequency of such waves is 1 Hz or lower, placing them in the infrasonic part of the audio spectrum.

In AM stereo, the bandwidth is too narrow to accommodate subcarriers, so the modulation itself is changed, and the pilot tone is infrasonic (below the normal hearing range, instead of above it) at a frequency of 25 Hz.

NASA Langley has designed and developed an infrasonic detection system that can be used to make useful infrasound measurements at a location where it was not possible previously. The system comprises an electret condenser microphone PCB Model 377M06, having a 3-inch membrane diameter, and a small, compact windscreen.Development and installation of an infrasonic wake vortex detection system By Qamar A. Shams and Allan J. Zuckerwar, NASA Langley Research Center, Hampton VA USA, WakeNet-Europe 2014, Bretigny, France. Electret-based technology offers the lowest possible background noise, because Johnson noise generated in the supporting electronics (preamplifier) is minimized.

The Allies of World War I first used infrasound to locate artillery.Wired Article, The Sound of Silence by John Geirland. 2006. One of the pioneers in infrasonic research was French scientist Vladimir Gavreau."Gavreau", in Lost Science by Gerry Vassilatos. Signals, 1999.

The outputs of a spatially distributed array of sensors were combined by the beam former, where the signals from one direction were added, while the effects of noise and interference from other directions were reduced. The main obstacle in the detection and analysis of infrasonic signals was the intrinsic pressure fluctuations due to air turbulence/wind noise, which was always present. Wind noise, caused by the passage of air over the microphone, limited the ability to collect infrasonic signature in a covert area. Wind noise levels increased with decreasing frequency and mean noise levels could have been equal or greater than the levels of the signal to be detected.

Infrasonic sensing arrays supported the U.S. Army’s 501st Military Intelligence Brigade in South Korea, fielded in 2001. It was also fielded to Iraq and Afghanistan in 2004. Information obtained with the research of infrasonic sensing arrays lead to the development of The Unattended Transient Acoustic MASINT Sensor (UTAMS) computer carried by the Aerostat of Persistent Threat Detection System (PTDS), which was an acoustic sensor used to detect the point of origin and the point of impact of missiles, IEDs, and missiles. Other applications included use by military or search and rescue teams, by field researchers studying volcanology or seismology, and by other geo-acoustic scientists and engineers.

Independent analysis published in December 1950 proved that the revised Williamson amplifier remained prone to both infrasonic and ultrasonic oscillations. According to the analysis, infrasonic open-loop response of the Williamson amplifier is shaped by three high-pass filters: two interstage RC filters, each with a cutoff frequency of 6 Hz, and the output stage RL filter, formed by the valves' output impedances and the transformer's primary inductance. At zero input signal, the nonlinear RL filter has a cutoff frequency of 3 Hz. This combination of cutoff frequencies, wrapped inside a 2030dB frequency loop, is unstable. Williamson tried to suppress it with a compensation network, also serving as a smoothing filter.

Several animal species are able to hear frequencies well beyond the human hearing range. Some dolphins and bats, for example, can hear frequencies up to 100,000 Hz. Elephants can hear sounds at 14–16 Hz, while some whales can hear infrasonic sounds as low as 7 Hz.

Echolocation clicks also contain characteristic details unique to each animal, which may suggest that toothed whales can discern between their own click and that of others. Mysticeti have exceptionally thin, wide basilar membranes in their cochleae without stiffening agents, making their ears adapted for processing low to infrasonic frequencies.

In 2001, ARL fielded infrasonic sensors (<20 Hz) in the Republic of Korea to meet a U.S. Army requirement for passive surveillance systems to detect artillery fire (8-10Hz) in the vicinity of the Demilitarized Zone. To meet the new requirement that came out of Iraq in 2004, ARL reconfigured the infrasonic sensor processing box to be used with acoustic sensors for the UTAMS detection of mortar fire (<100 Hz). The Rapid Equipping Force funded UTAMS in 2005 and 2006 for use in Iraq for Forward Operating Base protection. In 2006, UTAMS II was designed, based on lessons learned from previous fielding, and automatic alignment with two GPS sensors for precise pointing direction.

For instance, sometimes audio equipment will include a switch labeled "high cut" or described as a "hiss filter" (hiss being high-frequency noise). In the phonograph era, many stereos would include a switch to introduce a high-pass (low cut) filter, often called a "rumble filter", to eliminate infrasonic frequencies.

This range has shorter wavelengths which allow better resolution in imaging technologies. Medical applications such as ultrasonography and elastography rely on the ultrasonic frequency range. On the other end of the spectrum, the lowest frequencies are known as the infrasonic range. These frequencies can be used to study geological phenomena such as earthquakes.

Psychologist Richard Wiseman of the University of Hertfordshire suggests that the odd sensations that people attribute to ghosts may be caused by infrasonic vibrations. Vic Tandy, experimental officer and part-time lecturer in the school of international studies and law at Coventry University, along with Dr. Tony Lawrence of the University's psychology department, wrote in 1998 a paper called "Ghosts in the Machine" for the Journal of the Society for Psychical Research. Their research suggested that an infrasonic signal of 19 Hz might be responsible for some ghost sightings. Tandy was working late one night alone in a supposedly haunted laboratory at Warwick, when he felt very anxious and could detect a grey blob out of the corner of his eye.

Males create vibrations in the water to send out infrasonic signals that serve to attract females and intimidate rivals. The enlarged boss of the male gharial may serve as a sound resonator. Another form of acoustic communication is the headslap. This typically starts with an animal in the water elevating its snout and remaining stationary.

The infrasonic burglar alarm reacts to shock waves in the air that are produced by a break-in. When an intruder tries to break a window or force open a door or a window, the resultant air pressure variations (or shock waves) produce sound vibrations in the air, from 0.1 – 50 Hz. These low frequency sound vibrations are captured by a very sensitive receiver in the alarm and converted into electronic signals. These signals are then passed through a pre-programmed electronic filtering system for analysis and when found positive, activate the alarm siren immediately; thus dissuading the potential intruder still on the outside of the property. The system is very effective for residential security installations and is basically jam proof against electronic interference, due to its infrasonic technology.

The infrasonic sensing array, designed by the U.S. Army Research Laboratory (ARL), was a military device that detected and located explosive events with inaudible frequencies at long ranges, such as artillery, missiles, and helicopters through the use of the array process. It was also used for direction-finding and positioning for navigational purposes and for detecting atmospheric events for battlefield weather prediction.

Walrus males are known to use vocalizations to attract mates. Pinnipeds can produce a number of vocalizations such as barks, grunts, rasps, rattles, growls, creaks, warbles, trills, chirps, chugs, clicks and whistles. While most vocals are audible to the human ear, a captive leopard seal was recorded making ultrasonic calls underwater. In addition, the vocals of northern elephant seals may produce infrasonic vibrations.

Acoustic metamaterials control, direct and manipulate sound in the form of sonic, infrasonic or ultrasonic waves in gases, liquids and solids. As with electromagnetic waves, sonic waves can exhibit negative refraction. Control of sound waves is mostly accomplished through the bulk modulus β, mass density ρ and chirality. The bulk modulus and density are analogs of permittivity and permeability in electromagnetic metamaterials.

The Beirut explosion was similar to explosions of large amounts of ammonium nitrate in Tianjin, China, in 2015; in Texas City, United States, in 1947; or in Toulouse, France in 2001. An independent estimate by the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization based on infrasonic data obtained an explosive yield equivalent to 0.5–1.1 kT of TNT.

The entire spectrum can be divided into three sections: audio, ultrasonic, and infrasonic. The audio range falls between 20 Hz and 20,000 Hz. This range is important because its frequencies can be detected by the human ear. This range has a number of applications, including speech communication and music. The ultrasonic range refers to the very high frequencies: 20,000 Hz and higher.

The company's reference loudspeaker line. Features the company's latest drive unit technology and all the designs are based upon metal alloy and carbon fibre composite material construction. The series consists of, Vertex, Vector, Fulcrum, Discovery II, A.C.T. One Evolution, Endeavour and the flagship of the series, the Cardinal. The Torus Infrasonic Generator was brought into this product line in 2016.

However, at some locations such as Minneriya National Park, hundreds of individuals aggregate during the dry season, suggesting that grouping behaviour is flexible and depends on season and place. Like all Asian elephants, the Sri Lankan subspecies communicates using visual, acoustic, and chemical signals. At least fourteen different vocal and acoustic signals have been described, which include some low-frequency calls that contain infrasonic frequencies.

Frequencies capable of being heard by humans are called audio or sonic. The range is typically considered to be between 20 Hz and 20,000 Hz. Frequencies higher than audio are referred to as ultrasonic, while frequencies below audio are referred to as infrasonic. Some bats use ultrasound for echolocation while in flight. Dogs are able to hear ultrasound, which is the principle of 'silent' dog whistles.

Microsound includes all sounds on the time scale shorter than musical notes, the sound object time scale, and longer than the sample time scale. Specifically, this is shorter than one tenth of a second and longer than 10 milliseconds, which includes part of the audio frequency range (20Hz to 20kHz) as well as part of the infrasonic frequency range (below 20Hz, rhythm).Roads, Curtis (2001). Microsound, p.

Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term sonar is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extremely high (ultrasonic). The study of underwater sound is known as underwater acoustics or hydroacoustics.

The high level of attenuation within the infrasonic bandwidth (below 10 Hz) of the seismic field observed in natural oil-saturated porous media during the last years (explained by mesoscopic homogeneous models) is the main responsible of the passive seismic wave field shifting within a low frequency range. Pressure differences between regions with different fluid/solid properties induce frequency-dependency of the attenuation (Qp and Qs reservoir factors) and velocity dispersion (Vp, Vs) of the low frequency wave field. Infrasonic passive seismic spectroscopy quantifies the absorption and the wave field dispersion within the low frequency bandwidth giving the most predominant areas linked with possible oil-saturated and porous media. The low frequency seismic field is not usually reachable by the active seismic surveys being either the explosive waves mainly in the high frequency and the vibroseis currently built not to reach such a low frequencies.

In addition, many amplifiers include an adjustable low-pass filter, which prevents undesired higher frequencies from reaching the subwoofer driver. For example, if a listener's main speakers are usable down to 80 Hz, then the subwoofer filter can be set so the subwoofer only works below 80 Hz. Typical filters involve some overlap in frequency ranges; a steep 4th-order 24 dB/octave low-pass filter is generally desired for subwoofers in order to minimize the overlap region. The filter section may also include a high-pass "infrasonic" or "subsonic" filter, which prevents the subwoofer driver from attempting to reproduce frequencies below its safe capabilities. Setting an infrasonic filter is important on bass reflex subwoofer cabinets, as the bass reflex design tends to create the risk of cone overexcursion at pitches below those of the port tuning, which can cause distortion and damage the subwoofer driver.

Kamnik started playing the piano at the age of 5 and began producing electronic music at the age 14. At the age of 19, he formed the trance duo Andrelli & Blue with his brother's friend and signed to Infrasonic Recordings. Their debut single "Imagine" received support from notable DJs such as Armin van Buuren and Ferry Corsten. In 2009, Corsten requested the duo to remix his single "Lost".

The frequencies of sonars range from infrasonic to above a megahertz. Generally, the lower frequencies have longer range, while the higher frequencies offer better resolution, and smaller size for a given directionality. To achieve reasonable directionality, frequencies below 1 kHz generally require large size, usually achieved as towed arrays. Low frequency sonars are loosely defined as 1–5 kHz, albeit some navies regard 5–7 kHz also as low frequency.

The subwoofers' tuning ports were blocked and their input cards were altered. The modified cabinets were positioned in an open ring configuration: four stacks of three subwoofers each. Test signals were generated by a SIM 3 audio analyzer, with its software modified to produce infrasonic tones. A Brüel & Kjær sound level analyzer, fed with an attenuated signal from a model 4189 measurement microphone, displayed and recorded sound pressure levels.

Cut the Mic, formerly known as Infrasonic, is an annual event at Norwell, usually held in April. Bands and musicians within the school perform for the community. Norwell has held the Relay For Life since 2004 to fundraise for the Canadian Cancer Society. In the first five years of Relay For Life, the school has raised over $200,000 toward this cause.Relay For Life news release"Norwell’s 5th Annual Relay for Life".

In 2011, armed with new material, the trio released the E.P. "Don't Give Up," which was recorded at Infrasonic Sound (No Age, Wavves, Fools Gold) and mixed by Ali Nikou at BlasterMaster Productions in Los Angeles. Death to Anders released their E.P. on October 25, 2011 during L.A blog Buzz Bands' three-year anniversary show at The Echo in Echo Park, California, where they shared the bill with Everest and Hands.

The brown note is a hypothetical infrasonic frequency that would cause humans to lose control of their motions due to resonance. Attempts to demonstrate the existence of a "brown note" using sound waves transmitted through air have failed. The name is a metonym for the common color of human feces. Frequencies supposedly involved are between 5 and 9 Hz, which is below the lower frequency limit of human hearing.

The first attempts to build the Williamson amplifier revealed its tendency to oscillate due to very narrow phase margin. Astor and Langford-Smith, who gave the Williamson excellent ratings, reported that "for fairly large outputs at low frequencies a high frequency oscillation about 60 kC/s [kHz] would commence and be accompanied by a pulsed output of some other frequency". The Australians, armed with first-class test equipment, suppressed the 60 kHz oscillation with small capacitors on screen grids, but could not identify and suppress the cause of "some other" oscillations. Later, technicians of the United States Naval Research Laboratory examined seven different commercially available Williamson amplifiers, and found that all of them oscillated at infrasonic frequencies of 2...3 Hz. Replacement of output transformers affected stability only at audio and ultrasonic frequencies. The best transformers diplayed perfectly flat frequency response from 10 to 100000 Hz, but were also prone to infrasonic "breathing".

Prairie dogs similarly have complex calls that signal the type, size, and speed of an approaching predator. Elephants communicate socially with a variety of sounds including snorting, screaming, trumpeting, roaring and rumbling. Some of the rumbling calls are infrasonic, below the hearing range of humans, and can be heard by other elephants up to away at still times near sunrise and sunset. Orca calling including occasional echolocation clicks Mammals signal by a variety of means.

After puberty, male elephants tend to form close alliances with other males. While females are the most active members of African elephant groups, both male and female elephants are capable of distinguishing between hundreds of different low frequency infrasonic calls to communicate with and identify each other. Elephants use some vocalisations that are beyond the hearing range of humans, to communicate across large distances. Elephant mating rituals include the gentle entwining of trunks.

Infrasonic frequency response measurements include earthquakes and electroencephalography (brain waves). Frequency response requirements differ depending on the application.Luther, 1999, p. 141. In high fidelity audio, an amplifier requires a frequency response of at least 20–20,000 Hz, with a tolerance as tight as ±0.1 dB in the mid-range frequencies around 1000 Hz, however, in telephony, a frequency response of 400–4,000 Hz, with a tolerance of ±1 dB is sufficient for intelligibility of speech.

The non-audible component of the blast is an infrasonic overpressure wave that can cause damage to nearby fragile objects. Accessory devices such as muzzle brakes and muzzle boosters can be used to redirect muzzle blast in order to counter the recoil-induced muzzle rise or to assist the gas operation of the gun, and suppressors (and even muzzle shrouds) can be used to reduce the blast noise intensity felt by nearby personnel.

The Sinking-2 (Chinese: 沉-2, Transliteration: Chen-2) bottom mine was the first indigenous designed Chinese naval mine that could adopt a range of fuzes, such as acoustic, contact, infrasonic, ultrasonic and magnetic fuzes. The project was jointly developed by Fengxi Machinery Factory (Chinese: 汾西机器厂) and the 710th Research Institute in 1972, and was mainly used for coastal regions. The mine was accepted into service in 1975.

The electromagnetic spectrum extends from below frequencies used for modern radio to gamma radiation at the short-wavelength end, covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. In comparison, infrasonic frequencies range from 20 Hz down to 0.001 Hz, audible frequencies are 20 Hz to 20 kHz and the ultrasonic range is above 20 kHz. While electromagnetic waves can travel in vacuum, acoustic wave propagation requires a medium.

The Apocalypse Inside of an Orange is the fourth studio album by Omar Rodríguez-López, and the third released in the "Amsterdam series". The double LP was released on November 20, 2007.Infrasonic Sound: Pete Lyman discography The CD version followed in March 2008. As of December 2010, the clear vinyl edition is out of print; however, the album has been released in Europe too on Willie Anderson Recordings, both on cd and double black vinyl.

He has worked on the Armada record label, started by the world's No.1 DJ Armin Van Buuren, having featured on numerous compilations released by the label. He currently releases mainly on Interstate Recordings, a sublabel of the UK based record label, Infrasonic Recordings. During an interview with established magazine Pumped Audio in 2012, it was revealed that Desmond is the youngest musician to ever release a dance music track through a record label in Irish history.

The remote locking transmitter represents the first stage of security, while a console-mounted numerical keypad forms the second stage. To disarm the 6 points of immobilisation, the correct four-digit code must be entered into the keypad. The system also features an anti-hijack, mode, intrusion alert, false alarm prevention, internal screamer siren, infrasonic sensor, valet mode and anti cross- pollination software. The B4's instrument cluster is backlit and delivers excellent visibility under all conditions.

Two biomechanical features can trigger these traveling wave patterns, which are a low fundamental frequency and in the vocal folds, increasing longitudinal tension. At Amboseli, several different infrasonic calls have been identified. A greeting rumble is emitted by members of a family group after having been separated for several hours. Contact calls are soft, unmodulated sounds made by individuals that have been separated from their group and may be responded to with a "contact answer" call that starts out loud, but becomes softer.

Initially a researcher of whales with her then husband, Payne turned to investigating elephants after observing them at the Oregon Zoo in Portland. In 1984, she and other researchers discovered that elephants make infrasonic calls to one another that might be detectable at distances as far as ten kilometers. The calls aided in travel and mating. Payne founded the Elephant Listening Project (ELP) to use these calls as a means of measuring the behavior of elephants and the size of the elephant population.

Vladimir Gavreau, born Vladimir Gavronsky (died between 1968 and 1972), was a French scientist making experiments on the biological effects of infrasound. Gavreau was born in Russia. His interest in infrasonic waves first came about in his lab during the 1960s, when he and his lab assistants experienced pain in the ear drums and shaking lab equipment, but no audible sound was picked up on his microphones. He concluded that it was infrasound and got to work preparing tests in the labs.

With Howie's blessing, Levitin completed the production for the latter two and sold the distribution rights to a different independent label, San Francisco's Infrasonic Records, where they flourished. In 1989, Howie Klein was named General Manager of Reprise Records in Burbank, California and Levitin stayed to help run the label after Klein left. Three months later, Sandy Pearlman bought 415. By this time, Al Teller, who had been president of Columbia Records when the 415 partnership began, was now president of MCA Records.

Normal operating frequency range of the selected subwoofer model was 28 Hz to 150 Hz but the 12 enclosures at MythBusters had been specially modified for deeper bass extension. Roger Schwenke and John Meyer directed the Meyer Sound team in devising a special test rig that would produce very high sound levels at infrasonic frequencies. The subwoofers' tuning ports were blocked and their input cards were altered. The modified cabinets were positioned in an open ring configuration: four stacks of three subwoofers each.

Toulon was a bay horse with a white star, bred in the United Kingdom by his owner, Khalid Abdulla's Juddmonte Farms organisation. He was one of the best horses sired by Top Ville, the Irish-bred winner of the 1979 Prix du Jockey Club. Toulon's dam, Green Rock was a daughter of Infra Green, who won Prix Ganay and produced good winners including Infrasonic (Queen's Vase) and Greensmith (second in the St James's Palace Stakes). The colt was sent into training with André Fabre at Chantilly.

However, the experiment showing such actions did not follow the accepted protocol for tests of self- recognition, and earlier attempts to show mirror self-recognition in elephants have failed, so this remains a contentious claim. Elephants are also deemed to show emotion through vocal expression, specifically the rumble vocalization. Rumbles are frequency modulated, harmonically rich calls with fundamental frequencies in the infrasonic range, with clear formant structure. Elephants exhibit negative emotion and/or increased emotional intensity through their rumbles, based on specific periods of social interaction and agitation.

The band released one LP, 1987's Here Comes the World, on local label Infrasonic Records, before breaking up the following year. Written Work Stadtman began writing for Teleport City, one of the longest running cult cinema websites on the internet, in February 2008. Around the same time, he started his Rondo Award nominated blog Die, Danger, Die, Die, Kill! In March 2015, he released his first book, Funky Bollywood: The Wild World of 1970s Indian Action Cinema, which was published by Britain's FAB Press to international acclaim.

The has four inputs that can be switched via the front panel – Aux, Tuner, Phono, Tape. The manufacturer claims the phono input, which can also be used with high-output moving coil cartridges, contains a 6-transistor circuit "engineered for extremely low noise and nearly distortion-free performance". Reviewers note the pre-amplifier's "decent moving-magnet phono stage". The amplifier is bandwidth-limited, incorporating infrasonic and ultrasonic filters to supposedly reduce the effects of non-musical signals such as acoustic feedback, disc warps and electromagnetic interference on the musical signals.

This allows them to generate their characteristic ultrasonic waves that are above the human hearing range. In contrast, vocal folds of larger mammals, such as whales are greatly hypertrophied, which results in the production of infrasonic sounds far below the human hearing range. Some moths have developed a protection against bats. They are able to hear bats' ultrasounds and flee as soon as they notice these sounds, or stop beating their wings for some time to deprive the bats of the characteristic echo signature of moving wings on which they may home in.

Since "equalization" in the context of audio reproduction is not used strictly to compensate for the deficiency of equipment and transmission channels, the use of high and low pass filters may be mentioned. A high-pass filter modifies a signal only by eliminating lower frequencies. Thus a low-cut or rumble filter is used to remove infrasonic energy from a program which may consume undue amplifier power and cause excessive excursions in (or even damage to) speakers. A low-pass filter only modifies the audio signal by removing high frequencies.

Titan disposes of the creature by throwing him into Suffolk Bay, but is again attacked by Scream's 'infrasonic vibrations' and falls into the bay after him. The NSC pulls Titan out of the bay and he flies off after X. Catching up with the killer, they have a confrontation in a warehouse. X smashes a sink up side Titan's head, shattering it and releasing the cocaine it is made of into the air. X convinces Titan that he is a dupe for a drug lord, but Scream again attacks.

The Afflicted are a punk band (also considered a skate punk band) based in San Francisco, California. They were active from 1982–1988, consisting of Dan Rancid (lead vocals and lyrics), Barry Wilder (guitar), Frankie John Lennon (bass), and Daryl Bach (drums). They gained popularity with a cult classic, "Here Come the Cops" (produced by Daniel Levitin) that was featured on the International P.E.A.C.E. Benefit Compilation, a hardcore punk collection released by R Radical Records. They released an LP in 1985, also produced by Levitin, Good News About Mental Health, on Infrasonic Records.

High-pass and low-pass filters restrict a given channel's bandwidth extremes. Cutting very low frequency sound signals (termed infrasonic, or subsonic) reduces the waste of amplifier power which does not produce audible sound and which moreover can be hard on the low-range speakers. A low-pass filter to cut ultrasonic energy is useful to prevent interference from radio frequencies, lighting control, or digital circuitry creeping into the power amplifiers. Such filters are often paired with graphic and parametric equalizers to give the audio engineer full control of the frequency range.

Tornadoes are also not the only source of such sounds in severe thunderstorms; any strong, damaging wind, a severe hail volley, or continuous thunder in a thunderstorm may produce a roaring sound. Tornadoes also produce identifiable inaudible infrasonic signatures. Unlike audible signatures, tornadic signatures have been isolated; due to the long distance propagation of low-frequency sound, efforts are ongoing to develop tornado prediction and detection devices with additional value in understanding tornado morphology, dynamics, and creation. Tornadoes also produce a detectable seismic signature, and research continues on isolating it and understanding the process.

Thomas Ankersmit (born 1979, Leiden, Netherlands) is a musician and installation artist based in Berlin and Amsterdam. His main instrument, both live and in the studio, is the Serge analogue modular synthesizer. Physical and psychoacoustic phenomena such as sound reflections, infrasonic vibration, otoacoustic emissions, and highly directional projections of sound have been an important part of his work since the early 2000s. His electronic music is also characterized by a deliberate misuse of the equipment, using feedback and disruptions in the signal to create many of the sounds.

Infrasonic passive seismic spectroscopy (IPSS) is a passive seismic low frequency technique used for mapping potential oil and gas hydrocarbon accumulations. It is part of the geophysical techniques also known under the generic naming passive seismic which includes also passive seismic tomography and micro seismic monitoring for petroleum, gas, and geothermal applications. In a larger scale, passive seismic includes the Global Seismic Network (GSN) earthquake monitoring. Regarding petroleum and geothermal exploration (within a small scale), the effect of fluid distribution on P-wave propagation in partially saturated rocks is responsible for the low frequency reservoir- related wavefield absorption.

Cover of the 1990 pamphlet titled "Feraliminal Lycanthropizer" The Feraliminal Lycanthropizer is a psychotechnographic machineConnor, S., Dream Machines (London: Open Humanities Press, 2017), p. 131. invented by American writer David Woodard, whose 1990 pamphlet of the same title speculates on its history and purpose.Woodard, D., "Feraliminal Lycanthropizer" (San Francisco: Plecid General Outreach, 1990). The brief, anonymously published work describes a vibration referred to as "thanato-auric waves", which the machine electrically generates by combining three infrasonic sine waves (3 Hz, 9 Hz and 0.56 Hz) with tape loops of unspecified spoken text (two beyond the threshold of decipherability, and two beneath the threshold).

Mod-III Sensurround was a further refinement of the system to allow more control over level, timbre and placement of effects. Instead of a simple wide-range rumble that could be felt and heard, Mod-III used more narrow band extended low frequency effects in the 16–25 Hz range, in addition to the higher frequency program sounds and surround-sound effect. Thus, scenes could have dialogue and other audio at standard levels, plus the effect of movement from the infrasonic rumble, creating sensations that had not been possible in earlier Sensurround films. Mod-III Sensurround was used in Battlestar Galactica in 1978.

Hearing (or audition) is the ability to perceive sound by detecting vibrations (i.e., sonic detection). Frequencies capable of being heard by humans are called audio or audible frequencies, the range of which is typically considered to be between 20 Hz and 20,000 Hz. Frequencies higher than audio are referred to as ultrasonic, while frequencies below audio are referred to as infrasonic. The auditory system includes the outer ears, which collect and filter sound waves; the middle ear, which transforms the sound pressure (impedance matching); and the inner ear, which produces neural signals in response to the sound.

The 20 db (ten-to-one) feedback loop of the Williamson amplifier wraps around all four stages and the output transformer. According to Richard C. Hitchcock, "this is a severe test of design and is one of the outstanding features of the Williamson circuit." Williamson wrote that the depth of feedback can be easily increased from 20 to 30 dB, but the audible improvements of deeper feedback will be diminishingly low. All frequency compensation components are located in the first and second stages of the circuit: their local smoothing RC filters subtly alter frequency response at infrasonic frequencies.

Amateurs who copied the Williamson amplifier were unable to identify and fix its critical weak points. An amateur armed with an analogue multimeter could "see" infrasonic oscillations by watching the instrument needle, but fixing high-frequency issues required an oscilloscope with bandwidth of at least 1 or 2MHz bandwidth. In the 1950s bandwidths of many commercial oscilloscopes were too narrow for the task, and even these models were too expensive for the DIYers. Articles by professional engineers dealing with analysis and fine tuning of the Williamson amplifier were published relatively late, when the original DIY enthusiasm had already faded - in 1952, 1957, 1961.

The concept behind the Elephant Listening Project began to form in 1984 when Katy Payne, observing elephants in the Portland Zoo, discovered that elephants communicate in low frequencies. After four months in Portland, Cornell University's acoustic biologists Carl Hopkins and Bob Capranica partnered with Payne to record and measure the infrasonic communication and behavior of elephants. By 1999 Payne published her elephant discoveries in her book Silent Thunder, and the Elephant Listening Project was officially founded in the Laboratory of Ornithology to focus on long term research on forest elephants. In 2005 Katy Payne retired and Peter Wrege took over the project.

Major support for all operations at LEH are conducted through McMurdo Station run by a division of NSF, the United States Antarctic Program (USAP). LEH is used as a base of operations for the monitoring of Mt Erebus and maintenance of such equipment. The work force at LEH, which is composed of senior research scientists, professors and graduate students, maintains both the scientific and logistical equipment on the mountain. Gaseous emission concentration, composition and flux as well as thermal image stills, visible and IR video, and infrasonic, of the lava lake are all data collected by researchers based at LEH.

Tests of high-intensity infrasound on animals resulted in measurable changes, such as cell changes and ruptured blood vessel walls. In February 2005 the television show MythBusters used twelve Meyer Sound 700-HP subwoofers—a model and quantity that has been employed for major rock concerts. Normal operating frequency range of the selected subwoofer model was 28 Hz to 150 Hz but the 12 enclosures at MythBusters had been specially modified for deeper bass extension. Roger Schwenke and John Meyer directed the Meyer Sound team in devising a special test rig that would produce very high sound levels at infrasonic frequencies.

Studies on tigers have shown that acoustic energy peaks in the low frequency range and the power wanes in higher frequencies, as in many tiger vocalizations, yet a distinct pattern allows prusten to be distinguished. It has been found that tigers are most sensitive to lower frequencies and are likely able to hear in the infrasonic range, which is likely reflected in the production of calls such as prusten. It has also been hypothesized that hearing in the low frequency range is beneficial in communicating and locating prey in the low-visibility jungle habitats where these cats usually live.

When a wave train strikes a wall at an oblique angle, the reflected wave train departs at the supplementary angle causing a cross-hatched wave interference pattern known as the clapotis gaufré ("waffled clapotis"). In this situation, the individual crests formed at the intersection of the incident and reflected wave train crests move parallel to the structure. This wave motion, when combined with the resultant vortices, can erode material from the seabed and transport it along the wall, undermining the structure until it fails. Clapotic waves on the sea surface also radiate infrasonic microbaroms into the atmosphere, and seismic signals called microseisms coupled through the ocean floor to the solid Earth.

Dante Adrian White aka "Dante Aliano", "Dante Adrian", "Dante White-Aliano", and "Dante White", is a Rock and Roll and Alternative songwriter, vocalist, guitar player and recording artist from Monterey, California. His work has appeared on over 80 recordings on several record labels, including Gold Standard Laboratories, Dim Mak, Sympathy For The Record Industry, Infrasonic Sound, 10,000 Baby Names, Cold Sweat and Flapping Jet. He is currently the leader of the Los Angeles based band, Dante Vs Zombies. Previously, he was the main songwriter, vocalist and guitar player for The Starlite Desperation as well as the vocalist for The Lost Kids and a guitar player for The Detroit Cobras.

Deep feedback, triode-connected KT66 power tetrodes, conservative choice of standing currents, and the use of wide-bandwidth output transformer all contributed to the performance of the Williamson. It had a modest output power rating of but surpassed all contemporary designs in having very low harmonic distortion and intermodulation, flat frequency response throughout the audible frequency range, and effective damping of loudspeaker resonances. The 0.1% distortion figure of the Williamson amplifier became the criterion for high fidelity performance that remains valid in the 21st century. The Williamson amplifier was sensitive to selection and matching of passive components and valves, and prone to unwanted oscillations at infrasonic and ultrasonic frequencies.

Engineer Tim Samaras, his photographer son Paul, and meteorologist Carl Young were killed doing in situ probe and infrasonic field research by an exceptional combination of events in which an already large and rain-obscured tornado swelled within less than a minute to wide simultaneously as it changed direction and accelerated. Several other chasers were also struck and some injured by this tornado and its parent supercell's rear flank downdraft. Three chasers were killed, two in one vehicle and one in another, when their vehicles collided in West Texas in 2017. The most recent chasing related fatality was on the morning of June 20, 2019.

After many tours following the release of their self-titled debut, the once sizable collective organically evolved into a five-member band: vocalist/bassist Luke Top, guitarist Lewis Pesacov, drummer Garrett Ray, multi-instrumentalist Brad Caulkins, and percussionist Salvador Placencia. This line-up redefined their sound for their sophomore LP, Leave No Trace, much of which was written in Wonder Valley, California (an artist/musician collective in the Mojave Desert). It was recorded at infrasonic studios in Alhambra in East Los Angeles, according to Pesacov, who also produced the album. A notable distinction in Leave No Trace is that it is sung predominately in English.

Since infrasonic bass is felt, sub- bass can be augmented using tactile transducers. Unlike a typical subwoofer driver, which produces audible vibrations, tactile transducers produce low- frequency vibrations that are designed to be felt by individuals who are touching the transducer or indirectly through a piece of furniture or a wooden floor. Tactile transducers have recently emerged as a device class, called variously "bass shakers", "butt shakers" and "throne shakers". They are attached to a seat, for instance a drummer's stool ("throne") or gamer's chair, car seat or home theater seating, and the vibrations of the driver are transmitted to the body then to the ear in a manner similar to bone conduction.

Absence Makes the Heart Grow Fungus is the first instrumental and sixth overall studio album and by Omar Rodríguez-López, released by Infrasonic SoundCargo Records on September 19, 2008. It is one of four solo albums completed in 2001 by Omar Rodríguez-López during the interim period following the demise of At the Drive-In and the formation of The Mars Volta. Absence... was tracked at Doug Messenger's North Hollywood studio only a few weeks after Rodriguez-Lopez recorded A Manual Dexterity: Soundtrack Volume One there, and is comparable to that project in both sound and atmosphere. The album features several tracks that were "originally intended for use by The Mars Volta".

The gain of a good quality full-range audio amplifier will be essentially flat between 20 Hz to about 20 kHz (the range of normal human hearing). In ultra-high-fidelity amplifier design, the amplifier's frequency response should extend considerably beyond this (one or more octaves either side) and might have points < 10 Hz and > . Professional touring amplifiers often have input and/or output filtering to sharply limit frequency response beyond ; too much of the amplifier's potential output power would otherwise be wasted on infrasonic and ultrasonic frequencies, and the danger of AM radio interference would increase. Modern switching amplifiers need steep low pass filtering at the output to get rid of high-frequency switching noise and harmonics.

This is strongest when waves from different storms interact or in the lee of a storm which produce the required standing wave conditions, also known as the clapotis. When the ocean storm is a tropical cyclone, the microbaroms are not produced near the eye wall where wind speeds are greatest, but originate from the trailing edge of the storm where the storm generated waves interact with the ambient ocean swells.< Microbaroms may also be produced by standing waves created between two storms, or when an ocean swell is reflected at the shore. Waves with approximately 10-second periods are abundant in the open oceans, and correspond to the observed 0.2 Hz infrasonic spectral peak of microbaroms, because microbaroms exhibit frequencies twice that of the individual ocean waves.

In acoustics, microbaroms, also known as the "voice of the sea", are a class of atmospheric infrasonic waves generated in marine storms by a non-linear interaction of ocean surface waves with the atmosphere. They typically have narrow-band, nearly sinusoidal waveforms with amplitudes up to a few microbars, and wave periods near 5 seconds (0.2 hertz). Due to low atmospheric absorption at these low frequencies, microbaroms can propagate thousands of kilometers in the atmosphere, and can be readily detected by widely separated instruments on the Earth's surface. Microbaroms are a significant noise source that can potentially interfere with the detection of infrasound from nuclear explosions that is a goal of the International Monitoring System organized under the Comprehensive Nuclear-Test-Ban Treaty (which has not entered into force).

Law enforcement officer holding a Hypershield, an acoustic hailing device used for crowd and riot control One use of LRADs (long range audio devices) is deploying them to prevent people from entering line of fire areas Acoustic devices have been used for military purposes including to stress enemies, as an aid in interrogation, and to create "an infrasonic sound barrier". The British Army used "Squawk Boxes" to emit ultrasonic frequencies causing various discomforts.Bad Vibrations: The History of the Idea of Music as a Cause of Disease by Dr James Kennawa Audio harassment was also used by the U.S. military in the Vietnam War and was famously depicted in the fictional movie Apocalypse Now as helicopters descend on the enemy with loud speakers. Operation Wandering Soul broadcast voices purported to be dead Vietcong.

On 31 May 2003, a group of UK researchers held a mass experiment, where they exposed some 700 people to music laced with soft 17 Hz sine waves played at a level described as "near the edge of hearing", produced by an extra-long-stroke subwoofer mounted two- thirds of the way from the end of a seven-meter-long plastic sewer pipe. The experimental concert (entitled Infrasonic) took place in the Purcell Room over the course of two performances, each consisting of four musical pieces. Two of the pieces in each concert had 17 Hz tones played underneath.Infrasonic concert, Purcell Room, London, 31 May 2003, sponsored by the sciart Consortium with additional support by the National Physical Laboratory (NPL)Sounds like terror in the air Sydney Morning Herald, 9 September 2003.

Test signals were generated by a SIM 3 audio analyzer, with its software modified to produce infrasonic tones. A Brüel & Kjær sound level analyzer, fed with an attenuated signal from a model 4189 measurement microphone, displayed and recorded sound pressure levels. The hosts on the show tried a series of frequencies as low as 5 Hz, attaining a level of 120 decibels of sound pressure at 9 Hz and up to 153 dB at frequencies above 20 Hz, but the rumored physiological effects did not materialize. The test subjects all reported some physical anxiety and shortness of breath, even a small amount of nausea, but this was dismissed by the hosts, noting that sound at that frequency and intensity moves air rapidly in and out of one's lungs.

The reason for the discovery of this phenomenon was an accident: the aerologists working at the marine hydrometeorological stations and watercrafts drew attention to the strange pain that a person experiences when approaching the surface of a standard meteorological probe (a balloon filled with hydrogen). During one of the expeditions, this effect was demonstrated to the Soviet academician V. V. Shuleikin by the chief meteorologist V. A. Berezkin. This phenomenon drew genuine interest among scientists; in order to study it, special equipment was designed to record powerful but low-frequency vibrations that are not audible to human ears. As a result of several series of experiments, the physical essence of this phenomenon was clarified and in 1935 when V.V. Shuleikin published his first work entirely devoted to the infrasonic nature of the “voice of the sea”.

The Matterhorn is a subwoofer model completed in March 2007 by Danley Sound Labs in Gainesville, Georgia after a U.S. military request for a loudspeaker that could project infrasonic waves over a distance. The Matterhorn was designed to reproduce a continuous sine wave from 15 to 20 Hz, and generate 94 dB at a distance of , and more than 140 dB for music playback measured at the horn mouth. It can generate a constant 15 Hz sine wave tone at 140 dB for 24 hours a day, seven days a week with extremely low harmonic distortion. The subwoofer has a flat frequency response from 15 to 80 Hz, and is down 3 dB at 12 Hz. It was built within an intermodal container long and square. The container doors swing open to reveal a tapped horn driven by 40 long-throw 15-inch (40 cm) MTX speaker drivers each powered by its own 1000-watt amplifier.

For Ann (rising) is a piece of electronic music created by James Tenney in 1969. Tenney is the author of Meta (+) Hodos, one of, if not the, earliest applications of gestalt theory and cognitive science to music, and later "Hierarchical temporal gestalt perception in music: a metric space model" with Larry Polansky, and other works, the influence of may be seen in many of his pieces including the twelve-minute For Ann (rising). The piece is based upon the Shepard scale concept, named after Tenney's colleague at Bell Labs psychologist Roger Shepard, though the technique which the piece uses is more properly described as a continuous Risset scale or Shepard-Risset glissando . Each rising sine-wave-like glissando, between twelve and fifteen rising at any time, fades in and out, all entering a minor sixth below their predecessors, rising from the infrasonic to ultrasonic range, from below to above the ability to perceive pitch .