I'm surprised this idea for novelty performance art hasn't already been listed. For the price of a helium balloon and a simple, ummm, 'adapter' one can pre-fill one's colon with this versatile and fun gas.
Any subsequent flatulence will be an octave or two higher than normal and will provide hours of fun and laughs at parties. For highbrow events (or perhaps just marginally less lowbrow) a bit of rehearsal will allow the skilled practictioner to whistle classical tunes or perform bird imitations.
A more mundane usage around the office or elevator would be to allow you to misdirect bystanders as to the source of the noxious smells emanating from your direction.
I would not recommend hydrogen as a subsitute as that is a dangerous and non-classical gas. Say, did anyone just hear a canary warble?-- AusCan531, Jan 11 2012 "An ordinary bicycle pump can be used for this purpose, the rectal tube being attached to it." http://chestofbooks....html#ixzz1jCWTbx8YA link to a page containing this sentence. [tatterdemalion, Jan 11 2012] Le Pétomane.... http://en.wikipedia...ki/Le_P%C3%A9tomane [not_morrison_rm, Sep 05 2012] SF6-ready horn http://hackadaycom....08/09/kleinhorn.jpg [TomP, Sep 05 2012] Butt maybe these are more appropriate. http://en.wikipedia...A-BiRadial-horn.jpg [TomP, Sep 05 2012] Picture of arse gas noise dissemination using an exponential hollow form http://utu.morganli...ame=g24.001r.jpg#A2 [pocmloc, Sep 05 2012] Can a kazoo or vuvuzela be far behind? Perhaps featured in one of those street corner A Cappella groups (although, how you're going to get a tenor out of this I have no idea).-- Grogster, Jan 11 2012 Sulfur hexafluoride.-- tatterdemalion, Jan 11 2012 //Any subsequent flatulence will be an octave or two higher than normal// Not so. A farter is an idiophone; it is flesh that vibrates, rather than gas, so the pitch will not change.
For the same reason, despite popular conception, helium does not change the pitch of the human voice; the vocal folds vibrate at a frequency determined by their tension, not by the density of the gas. The squeaky voice is caused by a change in the resonant frequencies (formants) of the vocal tract, and is more akin to a high pass filter than a pitch shifter. Strange but true.
Helium does, however, change the pitch of a wind instrument, and of whistling, since in those cases it is gas that vibrates.-- spidermother, Jan 11 2012 [spidermother] I hear you speak your words of wisdom, Old Toothless One. And they are in the normal octave range. I bow deeply to your superior knowledge.-- AusCan531, Jan 11 2012 In the same manner, the resonant frequencies of one's buttocks may be influenced by Helium. If so, a test could be made in a helium rich room. Any ship's divers out there?-- Ling, Jan 11 2012 I almost certainly know people who have tried this.
It would be fairly hard to do though. People who are skilled at giving themselves enemas might be able to manage but they'd have to do it the other way up than usual, so maybe not. I'll ask around to see if this is baked at some point when i can get a bit of privacy.-- nineteenthly, Jan 11 2012 To clarify, by resonant frequencies of the vocal tract, I refer to the resonance of the air (or other gas) within the mouth and throat, not the resonance of any fleshy parts. Thus, I would not expect the resonant frequency of the buttocks to be affected by helium. There might be a small influence on the sound by vibration of gas within the rectum (hey, I didn't start this!), in which case helium would have some effect, but I predict that it will be slight.-- spidermother, Jan 11 2012 I'm not entirely sure of course, but I think the difference between end umm products, is that the vocal chords are immersed in helium when it happens. Thusly what is required is a reasonable method of ensuring there's helium not only on the inside, but on the outside: a butt megaphone perhaps.-- FlyingToaster, Jan 11 2012 OK, I just tried an experiment. I generated some hydrogen, confirmed that it created the squeaky voice effect and dramatically changed the pitch of a blown recorder, and tried blowing raspberries through pursed lips with and without hydrogen. I could not detect any difference.
The problem with the butt megaphone is that it would alter the sound, in a way that immersion in gas, or simply helium in ano, would not, as a megaphone acts as a resonator; a fairly weak one, admittedly, but enough to create the characteristic megaphonic voice distortion.-- spidermother, Jan 11 2012 Raspberries is not an accurate enough test for this theory. I'm sorry, but you're going to have to fill your ass with Hydrogen. And videotape it.-- DIYMatt, Jan 11 2012 Any ideas on how sound frequencies change as they pass through one medium to another and back again? Ie if sound waves travel through a tube filled with air, then through a membrane containing a medium with a different density (such as helium or water) then through another membrane back to air again would the pitch be the same as the 'original'?
If as [spidemother] says, the helium acts as a high pass filter then the lower frequencies would have been filtered out permanently rather than just be converted from low to high then back to low again.-- AusCan531, Jan 11 2012 //fill your ass with Hydrogen. And videotape it.// I'm sorely tempted, but don't hold your breath.
//how sound frequencies change as they pass through one medium to another and back again?// They don't change. It's not about the medium per se, it's that a vessel containing a medium acts as a resonator.
//would the pitch be the same as the 'original'?// Yes.
//If as [spidemother] says, the helium acts as a high pass filter then the lower frequencies would have been filtered out permanently rather than just be converted from low to high then back to low again.//
It's slightly more complicated than that. The vocal system could be considered as two components:
1) The vocal folds, which vibrate in a way determined by their tension and the flow of gas, and (I am suggesting) are only weakly influenced by the nature of the gas.*
2) A resonant system, which includes the whole body and (more importantly for this discussion) the gas within the mouth and throat. The resonant system does not alter the frequency (pitch) of any component of the vibration, but does (strongly) affect the relative strengths, and the phases, of the component frequencies. The nature of that effect, or the characteristics of the filter, if you will, is strongly influenced by the nature of the gas in the vocal tract.
A free, unconfined, elastic, isotropic medium does not act as a resonator, and allows sound to pass through it unchanged. A medium inside a partly open vessel (such as a wind instrument, a bottle, or a vocal tract) does act as a resonator (known as a Helmholtz resonator), and alters the relative strengths of the frequency components, and the phase characteristics, of a sound to which it is coupled.
Frequency components are neither filtered out permanently, nor changed from low to high or vice versa, merely attenuated or enhanced relative to other frequencies.**
* I think that, technically, the reason that the speed of sound of the gas does not strongly influence the vibration of the vocal folds is that there is a large impedance mismatch between gas and flesh.
** To a first approximation. A frequency very slightly different from a resonant frequency will excite the resonance, resulting in a very small, barely noticeable† frequency shift.
† An exception to this is where the exciting frequency and the resonant frequency are both clearly audible, and the difference can be heard as beats, or a tone that is unpleasantly out of tune with itself, as when playing a bowed instrument at a pitch slightly different from a resonance of the instrument or of another string.-- spidermother, Jan 11 2012 Thanks [sm]. I just knew this idea would lead to a valuable intellectual discussion when I posted it.-- AusCan531, Jan 12 2012 Only here... or in a bar after several pitchers of ale.
Anyway, the sound would maybe start as a continuous one, but then break down to a series of short bursts as the chortles of the producer take effect.-- Ling, Jan 12 2012 The internet has failed me: I can find no reference to "sulphur hexafluoride farting" anywhere.-- FlyingToaster, Jan 12 2012 The rectum and the buttocks are not the only factor. With blowing raspberries, the relevant bits are the buccal cavity, the lips and the tongue. There is a pair of long, thin tubes separating the mouth from the lungs and stomach. In the case of the buttocks and the rectum, there are two heavy wobbly things but also a system of potentially distended tubing such as the sigmoid and the descending and ascending colon nearby, which could vibrate themselves.
The reason i say this is, er, well, i happen to know that having a large volume of gas in the stomach and transverse colon changes the sound of my voice, i think because my diaphragm shifts but also because my lungs are then adjacent to an air-filled stomach and colon. As i suspect many Google-using 'bakers are aware during my more egocentric moments, i have a lot of practical experience in this area.
Please be patient, [FT]. I will provide one in the near future.-- nineteenthly, Jan 12 2012 I just checked...Methane is about Half the density of air. So a comparison experiment could be done relatively easily.-- Ling, Jan 12 2012 /The squeaky voice is caused by a change in the resonant frequencies (formants) of the vocal tract, and is more akin to a high pass filter than a pitch shifter./
I am wondering about this. It is possible to whistle at an oscilloscope and produce a pure tone. Somehow I have failed (failed!) to yet whistle after breathing helium, but I have a little more time, I hope. I will testify, though, that burping while whistling will greatly alter the tune produced - I think because of the denser CO2 largely comprising a burp. I think the hydrogen recorder note is the same principle.-- bungston, Sep 04 2012 <tries to visualize interior of [bungston]'s bedroom>
<succeeds>
<runs away, waving arms and screaming>-- 8th of 7, Sep 04 2012 Someday I will resolve this question through empirical experimentation, once and for all, then report back. I know that my kids possess a whoopee cushion and they occasionally bring home helium balloons. The problem is that I can just never, ever lay my hands on both at the same time.
If successful, we can move onto human experimentation - after trying it on [bungston] first of course.
Speaking of [bungston], when are we going to get another installment of Isis and Augi??-- AusCan531, Sep 05 2012 "fill your ass with Hydrogen. And videotape it.// I'm sorely tempted"
Sorely is the descriptive adverb. And this is far more fun than debating lawyers and the government.
By the way, I lit a flare in the roadway today, and am having second thoughts about the wisdom of that action, given the wisdom of my neighbors...-- normzone, Sep 05 2012 I was thinking the ancients might be ahead of us on this one (or should that be behind?) but scanning the Le Petomane stuff I can see no mention of it. Sealink.
//By the way, I lit a flare in the roadway today, and am having second thoughts
Reminded of story of how gas pipeline flare in USSR looked like a missile launch on US satellite...so be careful with that flare..-- not_morrison_rm, Sep 05 2012 Wouldn't [spidermother's] problem be solved by releasing one's gas into a horn? Thus we vibrate an air column and the pich will change in a similar way.
Such horns are already available for loudspeakers and it would take only a little modification to create a bottom-shaped hole instead of a 'speaker-shaped one at the small end. Lowther cabinets have particularly good treble response, but the sulphur hexafluridists among us will want something more like that shown in the [link]. My father has some similar ones, but alas I have no SF6.-- TomP, Sep 05 2012 //but alas I have no SF6.
Well, just get some SF5 and add the particles by hand, young people these days, no patience at all..<fall asleep reading the Daily Telegraph>-- not_morrison_rm, Sep 05 2012 SF6 in gelatin capsules with an enteric coating ?-- 8th of 7, Sep 05 2012 I was heartbroken when I saw somebody beat me to suggesting sulfur hexafluoride. [+]-- doctorremulac3, Sep 05 2012 I was thinking hydrogen as well, as it's easier, but then didn't wish to implicate myself in the Great Hinden-bottom tragedy of 2012...-- not_morrison_rm, Sep 05 2012 //Wouldn't [spidermother's] problem be solved by releasing one's gas into a horn// Baked some years ago - seal ink.-- pocmloc, Sep 05 2012 I should have known that, summat like that on the misericordia in me hometown church-- not_morrison_rm, Sep 05 2012 // just what it says it is. Squeeeak.// Perhaps be more meaningful to alter to, "Me Can't Believe it Not Cows Turd." Apologies to Harry Enfield, Dragon's Den."-- Lesser Spotted Kiwi, Sep 06 2012 Hey doc, it's ok, I think we lost him..Doc, are you there?-- not_morrison_rm, Sep 08 2012 Oi! [ n_m_r]. This is a serious post discussing important scientific principles so stop clowning around. <pssst, for a handful of croissants you and your pals can hang around here as long as you want - at least until the Borg show up. They're a bit scary>-- AusCan531, Sep 08 2012 Who'd have believed? Fugitive from me own post.....<hands over croissant> scratches "Doc - double-ended bulldozer" on the wall and moves on..-- not_morrison_rm, Sep 08 2012 //Wouldn't [spidermother's] problem be solved by releasing one's gas into a horn// I shall have to consult my brain care specialist on that issue.
A speaker-type horn would simply act as a resonator, having some effect on the relative loudness and duration of the frequency components, but not their frequency per se.
The arse trumpet in [poclmloc]'s link would have a better chance of producing a different fundament-al frequency depending on the gas's density.-- spidermother, Sep 09 2012 random, halfbakery