Talk:Infrasound

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A little something

This line from the first paragraph- " The ear is the primary organ for sensing infrasound, but at higher levels it is possible to feel infrasound vibrations in various parts of the body" it is not clear wht is meant by 'higher levels' . higher levels of pressure or what ? —Preceding unsigned comment added by 122.170.47.170 (talk) 11:08, 2 August 2009 (UTC)[reply]

Ghost in the machine

This section says that the research suggested that "many" supposed hauntings may be due to 19Hz hum. Sounds like a weasel word. I haven't read the research discussed, but the contents of the section suggests that actual number of sites that the research found any significant positive results for is ONE. Erikmartin (talk) 22:55, 14 October 2008 (UTC)[reply]

there'a a comment in the ghost in the machine chapter that says the wavelength at 19Hz is about 5000 miles? - I think this calculation is using the speed of light in a vacuum as about 300,000,000 m/s when it should be using the speed of sound in Air, about 340m/s - that gives a wavelength of 18 metres - so a half wave is about 9m? - entirely possible for a room to be 9m long. Alecost (talk) 22:26, 12 June 2008 (UTC)[reply]

You're right. I've removed the unnecessary paragraph discussing whether the room size is likely to have yielded an appropriately sized infrasonic standing wave. Binksternet (talk) 18:33, 13 June 2008 (UTC)[reply]

Scientists, many a time mix up the cause and the effect. For example generation of chemicals cause sensation of pain or the pain causes the generation of chemicals? Is it not possible that the ghosts' (spirit entities) activity can generate the very low frequency in our material plane? Polytope4D (talk) 21:02, 13 June 2018 (UTC)[reply]

Hearing Infrasound

What bugs me about articles on infrasound is that the first thing they all say is that it "cannot be heard by humans", I have discovered that I can hear infrasound originated by the build up of seismic tension before an earthquake within 500 miles radius (depending on magnitude). It's a very low frequency throbbing that is pulsed at irregular intervals and then seizes, or is drastically diminished in intensity, as soon as the earthquake has occured. The sound used to drive me bonkers until I discovered what it was. Now I am keeping a diary of the intensity of the noises and check once a month or so on the British Geological Survey website (http://www.earthquakes.bgs.ac.uk/) whether there had been any earthquakes, and sure enough there is always an earthquake that directly correlates to the peak-followed-by-trough in the noises that I have experienced. Most of these earthquakes are never reported in the media, you see, because they occur at sea or because noone is hurt and that's not of interest for the news... - Please tell me that I am not the only person who can hear the earth move!!! (152.78.18.62 16:41, 5 June 2007 (UTC)) (Sue, Southampton, UK)[reply]

See Taos hum for further information. The statement that humans can't "consciously" hear the sound smells suspicious, since the distinction between 'conscious' and 'subconscious' sounds like psychology. I should add that my subjective experience is that many of these effects could be the result of simple dizziness caused by the sound resonating in the semicircular canals, which I would speculate besides their usual role in orientation feel like they serve as a lower-frequency resonance chamber with a (very) vague directionality for sounds too gradually changing to be oriented by comparing the ears. But I've never heard the run-up to an earthquake - one night I heard a sound as if someone had dropped a car from the back of a tow truck and learned it was a magnitude 3.1 quake. Wnt (talk) 23:08, 7 October 2008 (UTC)[reply]

Some people can hear these things, others cannot, although sometimes it's more like feeling (some body parts are sensitive to infrasound) than hearing. I've heard/felt these sounds too over the years and believe they are related to microearthquakes and industrial machinery (both are common in the areas I've lived in). In most buildings I can feel/hear whether people are walking around in other rooms, without actually hearing footsteps, I can even tell the general direction of where they are relative to my own position in the building. In my dad's home in the woods I always knew when he was coming home when his car was still hundreds of meters away, even at such distances I could usually (not always though) distinguish between my dad's car and other cars. I don't think there's anything spooky about these things, I mean animals use infrasound all the time, whether it's a giant panda getting anxious hours before an earthquake, a dog getting excited when his owner's car is still a mile away or an elephant effortlessly finding a mate in the vast African savanna, we never ask ourselves why we can't do those things. Well, maybe some of us can, after all, it turns out we can learn echolocation too, so the human auditory system isn't as worthless when compared to animals as some people believe. I wouldn't be surprised if lots of indigenous tribes (and prehistoric humans) use(d) infrasound to hunt and survive but that it became a bit of a lost art when humans started farming and living permanently in large, noisy communities, that it's a skill you can develop through practice (if you have the right genes), like running a marathon, tightrope walking, faster-than-the-eye-can-see Kung Fu moves or human echolocation. Anyway, that's my $0.02.

213.93.101.238 (talk) 15:23, 29 June 2010 (UTC)[reply]

I'm feeling some sound more than hearing it, but others do not notice. After midnight, it increases, but what is it? Earthquakes don't follow a schedule, so it is something else. I'm picking up voices from air traffic , usually muffled, but yesterday I could follow a helicopter pilot's conversation. Maybe everyone has a unique audible range and pilots are in mine. A Psychology study found that noise evoked a stress response Without awareness of the noise. So is that the same as not consciously hearing? A tiger's roar terrifies people who do not know they hear it. What if infrasound from wireless internet transmission is interpreted by our brains like it's a tiger? That explains why people are addicted to their smartphones (epinephrine from stress) and getting so testy (fear of death).Romanfall (talk) 06:10, 22 February 2014 (UTC)[reply]

References

Don't say the scientist use names and references

Rumors

what about the rumors of it causing gastrointestinal problems at high volume?

what about extremely loud bass in car stereos collapsing lungs that have been weakened by disease? (this is real. i read it in a news article.) - Omegatron 20:02, Nov 25, 2004 (UTC)

supposedly the ear acts as a filter (which makes sense) and since no filter is ideal, will still respond to infrasound if it is loud enough, meaning people can supposedly hear down to 10 Hz or so at tremendous amplitudes. Is this real? - Omegatron 02:08, Jan 8, 2005 (UTC)

Very loud infrasound may be perceived as vibrations in any part of the body (it's what earthquakes are).

I am fairly sure that common speakers are not capable of emitting infrasound frequencies... how should we then understand the claim that some movies, such as Irreversible, use infrasound on the viewers? --Tjfulopp 20:20, 30 Jan 2005 (UTC)

Why wouldn't they be able to? - Omegatron 21:38, Jan 30, 2005 (UTC)

Because most speakers would have a very poor response at such low frequencies. —The preceding unsigned comment was added by 82.70.145.118 (talk) 16:26, 11 April 2007 (UTC).[reply]

Professional/cinema audio equipment can commonly reproduce frequencies as low as 12Hz, and I believe Dolby Digital theoretically reproduces 'sound' as low as 3Hz. (I don't have access to the technical specs to cite them.) If someone can find the THX spec that will shed more light (or sound) on the topic. Suffice to say, it's possible. 81.101.132.174 20:09, 13 September 2007 (UTC)[reply]

What about headphones? Can they hear sense infrasound?

Seems unlikely, since the lower the frequency, the greater the distance a speaker diaphragm has to be able to move to transmit a given power at that frequency. In other words, there's a size constraint -- you need big speakers for low sounds, given how speakers work. Besides that, almost all things that someone would be listening to on headphones will have been filtered at several points in the chain of recording and playback to only include the sounds in the normal range of hearing.Erikmartin (talk) 23:06, 14 October 2008 (UTC)[reply]

No, a speaker diaphragm needn't have a large xmax or surface area to transmit low frequencies. It only needs to track slow wave forms; an easy task. The problem is that the resulting low frequency output is going to be very low level for a small headphone driver which makes it very hard for humans to detect. Large air displacement makes it easier to detect. BTW, filtering of extreme lows may or may not happen in the signal chain, depending on what gear is chosen. Yes, certain pieces of gear have undocumented 5 Hz or 10 Hz or 15 Hz high-pass filtering which will have a profound effect on infrasound. Other pieces of gear won't have this filtering. The infrasound student will need to measure their test gear to see what the low-frequency corner is. Binksternet (talk) 00:14, 15 October 2008 (UTC)[reply]

Headphones need to create a vacuum seal for ears to pick up low frequencies. Well-fitting Earphones work.Romanfall (talk) 06:17, 22 February 2014 (UTC)[reply]

Perhaps this page should contain a small paragraph about the connection between infrasound and binaural beats

I don't know if I'm stretching it, but could animals detect disaster through infrasonic waves? Delete if irrelevant. Gotikplage 14:58, 18 December 2005 (UTC)[reply]

Elephants can communicate with 'infrasound' and detect impending storms, earthquakes etc in a similar way. See e.g. http://www.animalvoice.com/animalssixthsense.htm Meeprophone (talk) 20:53, 4 January 2008 (UTC)[reply]

Lower limit

Where did the lower limit of 0.001 Hz in our definition come from? All the references I can find (such as Oxford Reference Online and xreferplus.com) mention no such limit. --Heron 18:22, 25 October 2005 (UTC)[reply]

Someone who wrote the article probably thought that less than that is not a sound, but more like wind -Iopq 07:23, 17 May 2006 (UTC)[reply]

Nice point. But in that case perhaps even 0.5 Hz would equate to a blustery wind. Meeprophone (talk) 20:57, 4 January 2008 (UTC)[reply]

Well, given the speed of sound in rock and the size of the earth, it would seem that you wouldn't get any resonances lower than around that limit in earth seismology. So that's probably the limit at which it is used for any practical purpose. It's true... if you tried to transmit a sound anywhere near that through the atmosphere, it seems like it would be better described as a local weather pattern than a sound. Erikmartin (talk) 23:23, 14 October 2008 (UTC)[reply]

Delete this if I'm wrong, but isn't the lower limit of Hz scale 0? As in 0 cycles per minute? — Preceding unsigned comment added by 67.224.60.79 (talk) 22:48, 24 August 2012 (UTC)[reply]

Vladimir Gavreau

I added a small paragraph about Vladimir Gavreau. He does not have a page about him in Wikipedia, but he is an important person to know about when dealing with infrasound. I'll include my book sources on the page as well. (Sorry I was not logged in when I decided to post that.) Gotikplage 14:36, 18 December 2005 (UTC)[reply]

look at this link please: [1] search for Gavreau. Redecke 18:20, 27 August 2006 (UTC)[reply]

miles

When mentioning miles, mention kms, and first.

lowest frequency

I was messing around with Audacity and the generate tone function, I can only hear sound at 50Hz and higher is that normal?

It's your speakers. -Iopq 07:23, 17 May 2006 (UTC)[reply]

Also remember that human hearing is generally 20hz to 20khz. But that is on average, and not everyone hears the same frequencies equally.

20khz? My physics techer envied us students in school for hearing such frequencies, and even most students didn't hear much anymore at that frequency range. Note that as we humans age, our hearing is getting worse, so someone in his or her fifties is likely to not hear sounds higher than 13 to 15khz.--210.225.86.130 (talk) 00:04, 4 February 2008 (UTC)[reply]

Most people never have the capacity to hear 20Hz or 20KHz, however these figures are used as rough guides for the audible range because they're round figures and most people can hear close to their frequencies. — Preceding unsigned comment added by 86.175.64.129 (talk) 12:41, 25 August 2012 (UTC)[reply]

Effects on other sences

Dr. Ciaran O'Keefe has mentioned that infrasound that's on the coops of human hearing can play on our other senses such as 'corner-of-the-eye phenomena' (vision), however can it affect our sense of smell or any other senses? -- Fribins talk

Vic Tandy

I have added a section on research by the late Vic Tandy on Infrasound and ghosts. I have tried to back-up a lot of my text with references (hope I cited them ok - still quite new here). However, some of the information was from a talk he gave Coventry Magic Circle, and from the occasional conversations I had with him after I joined the magic society that he belonged to.StephenBuxton 21:02, 5 February 2007 (UTC)[reply]

Why does this section mention haunting of Edinburgh Castle with a link to an article about South Bridge (footnote 7)? They're at opposite ends of the town!

Radio

Bill Bailey presented a radio documentry on Infra-sound The Hunt for the Hum. You can listen to it (up until 9th feb 2007) here:http://www.bbc.co.uk/radio/aod/radio4_aod.shtml?radio4/huntforthehum

Thought you might be interested StephenBuxton 21:02, 5 February 2007 (UTC)[reply]

cite for "resonant frequency of the eye"?

The "18.98Hz" figure cited sounds like BS to me; "around 19Hz" might be quite reasonable, but with that level of significant figures? Doubtful. Anybody have a cite for the details/background of that? Eye doesn't have it. --moof 22:53, 24 February 2007 (UTC)[reply]

I had a look in Vic Tandy's report, and it cites a NASA technical report that states it is 18 Hz. I have modified the text accordingly.StephenBuxton 07:51, 22 March 2007 (UTC)[reply]

Has anyone actually found or read this supposed report? The only information I could find on it were discussions of infrasound that referenced the report, typically as a second- or third-hand source. It may be a good idea to try and find out whether or not this report actually exists. 216.184.23.58 (talk) 16:49, 4 September 2008 (UTC)[reply]

I've added full references, including links to PDFs, for both The Ghost in the Machine and Something in the Cellar. Jamesscottbrown (talk) 20:58, 17 January 2010 (UTC)[reply]

I found the paper. It's from 1976: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA030476&Location=U2&doc=GetTRDoc.pdf I'm sure there must be a better paper now, the camera technology alone has to have completely overtaken this poor old thing. So I totally agree that around 19 Hz is a far more reasonable claim. Note: A more modern paper or one more applicable to a free standing human would be preferable.

It seems extremely unlikely that the principal acoustic resonance of the eye would be as low as 18 Hz; the eye is far too small for that. So I carefully read the referenced paper -- and I have to say it is being badly misinterpreted, in several ways. Most importantly, the resonance to which they refer is a biomechanical one, nothing at all to do with acoustic coupling. It actually refers to the frequency of vertical vibration, imposed on the head as a whole, which gives the greatest difficulty in focusing the eyes on a nearby target (specifically, a pilot's instrument panel.) -- 202.63.39.58 (talk) 10:18, 15 January 2014 (UTC)[reply]

202.63.39.58, people who claim to have scientific data may manipulate information to match what they want to publish on Wikipedia. I hope that's not the case. Unless you are a top level administrator, there is little you can do about changing it. Polytope4D (talk) 07:59, 14 June 2018 (UTC)[reply]

Broken Link - help please!

The link to the pdf document Ghost in the Machine no longer works, as it appears that the site no longer exists. I suspect that the site might have once belonged to Vic, and as he died a couple of years back, he isn't about to repair whatever the problem is with the site. Did anyone make a copy of the file while it was available? StephenBuxton 09:33, 27 April 2007 (UTC)[reply]

Infrasound audio file?

Could a link to one be included in the page? If not, could one be placed below? Thanks. —Preceding unsigned comment added by 71.220.206.203 (talk) 01:40, 26 October 2007 (UTC)[reply]

Please? One that is in a form that can be heard by headphones. Thank you! 163.41.138.2 03:04, 29 October 2007 (UTC)[reply]

Here's a zipped two-channel 'stereo' WAV file that is thirty seconds of pure 16 Hz sine tone followed by two seconds of silence, with identical information on both channels (monophonic). Your headphones and whatever headphone amp you have aren't likely going to be able to reproduce this very strongly; I'm going to go out on a limb and suggest that you'll be hearing more 48 Hz (3rd harmonic) than 16 Hz true sine. Or not... maybe you're one of the few who have extremely fine low frequency-capable equipment. Binksternet 06:15, 29 October 2007 (UTC)[reply]

Church organs

Somewhere, too long ago to be able to cite source, I read that the large organs of large churches and cathedrals were deliberately designed to produce very low bass notes (incorrectly called subsonics); the reason given was that this was intended to induced a sense of awe (or religious feeling). The rationale was that the vibration was picked up by the gut and was mistakenly attributed to emotion. I thought this was widely-known and commonly-accepted.
Many websites report "Longer pipes in church organs also create infrasound, which many believe gives the music a particular atmospheric power." Christianity Today reported in 2003 that two British scientists say infrasound explains why large church organs increase spiritual sentiment, --The Lesser Merlin (talk) 13:22, 7 February 2008 (UTC)[reply]

Organ pipes put out quite a lot of energy at one octave above their fundamental. The way I understand it, most of the sound one hears is this harmonic. Many of the lowest organ pipes are tuned to 16 Hz--what you hear from them is a strong 32 Hz output. Certainly, awe is a part of the resulting sound, but I would downplay the infrasound element. There is one 8 Hz organ pipe in Atlantic City; that monster is certainly an infrasound producer. Boardwalk Hall Auditorium Organ Binksternet (talk) 14:46, 7 February 2008 (UTC)[reply]

Further... Several pipes sounded together have been used to produce infrasonic beat frequencies. Binksternet (talk) 18:23, 25 May 2008 (UTC)[reply]

List of freqs

I've twice deleted the list of infrasound frequencies added by User:72.153.92.44. The deleted list makes the mistake that single frequency values are called "chords" (they are called "notes") and assumes that musical notes are what people are interested in within the subject of infrasound; most readers would be interested in physical, physiological and psychological effects. Such effects do not fall under regularly-spaced musical frequencies--they happen at all infrasound frequencies. It's debatable whether any musicality exists below 16 Hz, let alone equal-tempered note values. I see no need why this listcruft should be allowed in the article. Binksternet (talk) 15:50, 14 March 2008 (UTC)[reply]

Deleted list once again. Please discuss your intention before adding it again. Binksternet (talk) 00:10, 18 March 2008 (UTC)[reply]

Noise studies

List of noise studies that I wanted to place here as possible references:

Belojević G, Öhrström E, Rylander R. Effects of noise on mental performance with regard to subjective noise sensitivity. Int Arch Occup Environ Health 1992;64:293-301.
Benton S, Leventhall HG. Experiments into the impact of low level, low frequency noise upon human behaviour. J Low Freq Noise Vibr 1986;5:143-162.
Berglund B, Hassmén P, Soames Job RF. Health effects induced by low-frequency noise: A critical review. Arch Center Sensory Res 1994;1:1-28.
Cohen S. After effects of stress on human performance and social behaviour: A review of research and theory. Psychol Bullentin 1980; 88:1:82-108.
Glass DC, Singer JE. Urban stress: Experiments on noise and social stressors. Academic Press, Inc, 111 Fifth Avenue, New York, USA, 1972, pp 3-182.
Ising H, Braun C. Acute and chronic endocrine effects of noise: Review of the research conducted at the Institute of water, soil and air hygiene. Noise & Health 2000;7:7-24.
Ising H, Ising M. Chronic cortisol increases in the first half of the night caused by road traffic noise. Noise & Health 2002;7:13-21
Kjellberg A, Muhr P, Sköldström B. Fatigue after work in noise – an epidemiological survey study and three quasi-experimental field studies. Noise & Health 1998;1:47-55.
Landström U, Liszka L, Danielsson Å, Linsmark A, Lindqwist M, Söderberg L. Changes of wakefulness during exposure to infrasound. J Low Freq Noise Vibr, 1982;1:2:79-87.
Mirowska M. An investigation and assessment of annoyance of low frequency noise in dwellings. J Low Freq Noise Vibr 1998;17:119-126.
Osguthorpe DJ, Mills JH. Nonauditory effects of low-frequency noise exposure in humans. Otolaryngology – Head and Neck Surgery 1982;90:367-370.
Persson Waye K, Rylander R, Benton S, Leventhall HG. Effects on performance and work quality due to low frequency ventilation noise. J Sound Vib 1997;205:467-474.
Persson Waye K, Rylander R. The prevalence of annoyance and effects after long-term exposure to low frequency noise. J Sound Vib 2001;240:483-497.
Persson Waye K. Effects of low frequency noise in the occupational envirornment – present knowledge base. Proceedings of the International Congress and Exposition on Noise Control and Engineering, August, Dearborn, Mi, USA, 2002, N273.

Binksternet (talk) 18:23, 25 May 2008 (UTC)[reply]

Elephants

[About infrasouds] Elephants, in particular, produce infrasound waves that travel through solid ground and are sensed by other herds using their feet (although they may be separated by hundreds of kilometres).

[Animal reactions] Elephants have been known to hear infrasound from two and a half miles away.

Which is it ? —Preceding unsigned comment added by Chris CII (talk • contribs) 12:52, 8 October 2008 (UTC)[reply]

Infrasound or electromagnetic waves? Infrasound is on the EM spectrum. Is this just a difference in terminology?Romanfall (talk) 06:34, 22 February 2014 (UTC)[reply]

Non-hearing detection

This article claims that infrasound cannot be consciously detected, but can't such vibrations be felt? -- Beland (talk) 18:09, 9 October 2008 (UTC)[reply]

Depends on the strength of vibration, and on other sensations masking your ability to detect. You probably wouldn't feel much steady-state infrasound transmitted to your body in the water if you were swimming, but you might feel it under your hand if you were standing still and the thing you were holding was vibrating strongly at an infrasound frequency. Infrasound waves in the air, if high enough amplitude, would cause your clothing to move back and forth, especially your pant legs. Binksternet (talk) 18:23, 9 October 2008 (UTC)[reply]

A familiar case of an irregular infrasound comes in the winter, when closing an interior door in a room with the exterior windows now shut. Unlike in summer, the door resists closing and there is a burst of wind around the edges. There is a brief feeling of lower pressure in the room. One can hear the windowpanes shift slightly in response to the pressure. In the same way, infrasound can make bottles vibrate against one another, metal parts rattle and so on. As in the case of the door closing, infrasound requires movement of air, but not really very much; the important thing is the change in pressure. A strong, steady wind might not produce infrasound if it does not flow past obstacles in a turbulent way. Wnt (talk) 03:52, 17 October 2008 (UTC)[reply]

Artificial infrasound sources

This article should collect a set of artificial infrasound sources. Some obvious cases[2] include car windows, woofers, and ventilation "rumble" in large buildings. One problem is that I think some sources are inaccurate; for example, this one[3] claims that opening a single rear car window produces less infrasound than opening the window near the driver, but my impression is that the sound from a lone rear window is actually much louder than if both front and rear windows are open, or even if both rear windows are open (the air gurgles out of a lone rear window like water from a soda bottle). As an empirical observation I think a duct has to be at least 1/2 meter in some dimension to produce much infrasound and the worst culprits are close to a meter, which I assume is why the first source says 'large' buildings. Oh, and the loudest single-frequency infrasound sources to my ears are certain residential oil delivery trucks. Wnt (talk) 03:48, 15 October 2008 (UTC)[reply]

Effect of infrasound on internal organs

why didn't anyone mention it in the topic? i know from my biophysics course that certain low frequencies can induce the urge to urinate or defecate(by achieving the natural frequency of the urinary bladder or that of the rectum). also check out this file

ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPdf/Infrasound.pdf

and this as well

www.geocities.com/toniwinkler/lowFreq.pdf --7amada'sback:) (talk) 02:37, 6 December 2008 (UTC)[reply]

Did they require diapers in the class? :P .... Binksternet (talk) 02:57, 6 December 2008 (UTC)[reply]

Pseudoscience references?

The section on 'Human reactions' refers to a health syndrome that maybe doesn't exist, without any citation of references to verify who it is that believes that wind turbines produce a unique form of infrasound that results in 'the syndrome' (using weasel words: "believed by some"). Also, the 'HowStuffWorks' reference citation for the para is probably not a great or reputable source for referencing on wikipedia (IMO). I have resisted changing anything immediately, but just added tags for citation, clarification, and weasel words, and am considering deleting that entire paragraph or doing some extensive editing (with reputable referencing). I would welcome feedback on this before I get carried away...AStephenGray (talk) 16:00, 21 April 2011 (UTC)[reply]

There are a few better sources, some of which are listed at the HowStuffWorks page. One of them is http://www.bwea.com/pdf/briefings/lfn_summary.pdf which, if quoted, would not yield the same text we have now in the article.

I think our text should follow our best sources. Binksternet (talk) 16:43, 21 April 2011 (UTC)[reply]

Tigers

Nothing about the discovery channel episode on tiger's producing infrasound? http://www.youtube.com/watch?v=Ms4KFAjDPB8 Daniel Christensen (talk) 23:32, 9 July 2011 (UTC)[reply]

Did Hitler use infrasound to incite anger in crowds?

The article claimed he did without citation, until 68.5.148.66 cited it to http://www.lowertheboom.org/trice/infrasound.htm, which does not appear to meet Wikipedia's criteria for a reliable source. The claim triggered my BS detector. Googling reveals a bunch of dubious websites and dodgy books that repeat the claim, including some that indicate their own suspicion by prefacing it with "Legend has it that...". I think if the claim were true, it would be reported in a decent, mainstream source. I've removed the surprising claim pending a source authoritative enough to support it (WP:REDFLAG). Adrian J. Hunter^{(talk•contribs)} 02:33, 16 October 2011 (UTC)[reply]

Much has been written about Hitler's use of sound amplification at the annual Nuremburg rally, but nothing about infrasound. The sound gear used at Nuremburg was not capable of low frequencies, let alone infrasonic frequencies. They used flared metal horns with compression drivers, the same as found at your usual racetrack, airfield, or military base. Even without very low frequencies, Hitler's voice was described by participants as hypnotic. This was not electronic trickery; it was his strong personality.

The text you removed said "during World War II" but Hitler did not speak to large rallies during the war. The last Nuremburg rally was 1938. During the war, Hitler spoke over radio and was also recorded for later broadcast.

The text should stay out of the article. Binksternet (talk) 17:06, 16 October 2011 (UTC)[reply]

ISO 7196

Apparently not mentioned, but certainly of interest:

"ISO 7196:1995 Acoustics -- Frequency-weighting characteristic for infrasound measurements

Specifies a frequency-weighting characteristic, designated G, for the determination of weighted sound pressure levels of sound or noise whose spectrum lies partly or wholly within the frequency band from 1 Hz to 20 Hz."

Heiko242 (talk) 12:53, 18 September 2014 (UTC)[reply]

My edit to Infrasonic 17 Hz tone experiment

I removed several citations for weasel words from the quote by Professor Richard Wiseman; since the passage is a direct verbatim quote I don't believe it's necessary or appropriate to alter the speaker's words to fit our style guide - furthermore, paraphrasing or expanding on his statement in the absence of secondary sources would fall under original research.

If secondary sources exist that expand on Professor Wiseman's statement, then I invite another editor to include them in that section.

Will the Great (talk) 03:51, 23 April 2015 (UTC)[reply]

Infrasonic Sound Experiment

As a tuba player, I am aware that the Bb tuba, in the hands of a competent player, is capable of producing sounds of 17Hz and lower. These sounds, when played quietly in tune with the rest of the ensemble, would normally be expected to produce a positive response in the listener, albeit he/she might be unaware of the reason. 17Hz is a rather flat C#, and can be expected to be experienced by many as an out-of-tune musical note. I cannot help wondering whether some of the negative effect experienced by listeners may be at least partly because of the musical effect of the sound, rather than its infrasonic qualities. — Preceding unsigned comment added by 194.62.232.103 (talk) 15:43, 10 August 2017 (UTC)[reply]

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Correspondence of "Infrasound for nuclear detonation detection" to "Human reactions"

It seems to me that using ~ for detection of events is not a human reaction. Theanswertolifetheuniverseandeverything (talk) 22:06, 5 June 2018 (UTC)[reply]

Possible misconception

Regarding this paragraph:

 "A scientist working at Sydney University's Auditory Neuroscience Laboratory reports growing evidence that infrasound may affect some people's nervous system by stimulating the vestibular system, and this has shown in animal models an effect similar to seasickness.[35]"

Please consider that the information might not be scientific. I was searching for the both the study and the "researcher" and I wasn't able to find them. So I run into this: https://waubrafoundation.org.au/wp-content/uploads/2015/03/King-Simon-Legal-Move-Threaatened-Over-Media-Watch-Report.pdf 145.90.159.109 (talk) 14:15, 21 September 2019 (UTC)[reply]

The opening sentence and paragraph are problematic

In the first sentence of the current version it is implied that the terms "infrasound" and "low-frequency sound" are synonymous. That is not how the terms are supposed to be used, neither in popular or scientific contexts. Cf. the abstract of the peer-revied scientific paper by Moller H., Pedersen C.S. (2004), "Hearing at low and infrasonic frequencies", Noise & Health 6 (23), pp. 37-57: "Sound at 20-200 Hz is called low-frequency sound, while for sound below 20 Hz the term infrasound is used".^[1] Sometimes "Infrasound" may be interpreted as a subset of "low frequency sound" but the connotations are typically quite different.

Furthermore, the same sentence ends with "sound waves with a frequency below the lower limit of audibility (generally 20 Hz)." It is a misconception, that there is such lower limit of audibility at 20 Hz, although widespread and stated in a number of publications. The hair cells (which generate the signals the auditory cortex receives) are positioned along the basilar membrane and will primarily be excited by sound energy at the specific frequency which corresponds to a local resonance at that particular point along the basilar membrane. Since such local resonances occurs approximately in the frequency range from 20 kHz down to 16-20 Hz, there will be "dedicated" hair cells in this frequency region, due to where they are positioned along the membrane. However, the hair cells also react to sound of other frequencies than what is amplified by the associated resonance, but the stimuli just need to be much stronger in such cases (cf. sound masking). That is why the sensitivity of sound drops quickly below 20 Hz - i.e. the basilar membrane does not yield any resonances at any positions for such sounds and thus the stimuli need to be stronger to be perceived. This can be seen at various "equal loudness contours" which has been presented down to at least 4 Hz in some cases. For the same reason, tonal sensation drops quickly below 20 Hz (and so the character of the perceived sound will change). Thus, sounds below 20 Hz sure are audible, although they are often too soft to be heard (which often is the case also for sounds above 20 Hz since the equal loudness contours starts to increase steeply already below about 200-300 Hz, i.e. in the low-frequency sound range).

And so, obviously this Wikipedia article advertises two common misconceptions already in the opening sentence, although there is an implicit correction of one of them already in the next sentence (contradicting the statement there is a limit of audibility at 20 Hz). But it seems as these sentences are more or less citations from the abstract of the reference I gave above, but without any references to the source and slightly alterations that obscures the fact that infrasound is audible (the second sentence is strikingly similar):

Wikipedia: "Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing infrasound, but at higher intensities it is possible to feel infrasound vibrations in various parts of the body." Moller et al: "The hearing becomes gradually less sensitive for decreasing frequency, but despite the general understanding that infrasound is inaudible, humans can perceive infrasound, if the level is sufficiently high. The ear is the primary organ for sensing infrasound, but at levels somewhat above the hearing threshold it is possible to feel vibrations in various parts of the body."

It is not pretty to copy (almost) word by word and make no references (the definition of plagiarism). Correct citations should be given, and all ambiguities shoud be removed. I stopped reading after the first paragraph, but the notion is that the whole article needs be thoroughly reviewed by someone with deep knowledge in the field. 81.25.151.84 (talk) 19:06, 4 August 2020 (UTC)DG[reply]

References

^ http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2004;volume=6;issue=23;spage=37;epage=57;aulast=Moller

Low-frequency oscillators

Can someone more knowledgable about synthesizers confirm whether LFOs generate infrasound? Easily accessible sources mostly say that they generate "inaudible frequencies," but I'm not sure whether this means sound below the human hearing range (infrasound), or internal control frequencies that are not accompanied by any sound at all. Marisauna (talk) 16:42, 13 January 2023 (UTC)[reply]

Good article

Very good and detailed article.. It is interesting how today there are studies that show that they cannot cause dizziness or nausea, although as mentioned in the article, this is exactly how they were initially discovered, when those people felt sick in the building of concrete. Regarding the detection of infrasounds, I would like some more information because the article also says that after their discovery in 1957, it became routine to measure their presence in buildings.. With what equipment? NASA probably only recently developed that electret system.. The ordinary electret can detect infrasounds, the amplifier can amplify them but I don't know what sound card can play them because modern sound cards are not sensitive to infrasounds.. In any case, the article is interesting. 86.126.133.139 (talk) 11:31, 16 March 2024 (UTC)[reply]

? They (that part of the acoustic spectrum) were used in WW1. What leads you to believe they were discovered in 1957??? (World War I occurred a few months before 1957, if I recall correctly.) This article is a MESS. I HOPE, but do not know, that Wikipedia policy is to REMOVE incorrect information. I HOPE that despite the large number of people speculating this or that effect, that the ACTUAL STUDIES (showing NO EFFECT) take priority. This article treats them (the good studies) as a footnote, burying them at the ends of most sections full of absolute garbage. This article seems to be an oil-and-water mix of true believers and science/engineering research. For instance, it claims NASA says 18 Hz is a resonance, citing a guy's PhD Thesis, Indiana University, 1973, by way of an Air Force Technical Paper. This is NOT "NASA". The paper itself used 15 test subjects (officers and enlisted in USAF) and the data (see Figure 10, pg 39) is not convincing. (The standard deviation (ONE std dev!!) at 18 Hz overlaps the means at 15 and 21 Hz. That is, there's no "peak" there at any reasonable level of confidence. (The only 'statistical analysis' done was computation of std dev and mean! (Suggesting the student's lack of statistical sophistication... But then again, with N so small, why bother?)98.17.181.251 (talk) 01:00, 20 June 2024 (UTC)[reply]

There are some studies stating they can affect the heart

Regarding the person who died after being exposed to infrasound,i found this study stating that high intensity infrasound exposure can affect the heart..So it's not just a myth after all. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8411947/ 86.126.133.187 (talk) 13:38, 18 March 2024 (UTC)[reply]

[1] ttp://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2004;volume=6;issue=23;spage=37;epage=57;aulast=Moller

[1]