what does helium do to your vocal cords
Why Does Helium Bear upon Your Vocalization?
Most kids would hold: Sucking a lungful of helium out of a airship makes your voice audio hilarious. Simply opposite to pop conventionalities, the switch from air to helium gas doesn't actually increase the pitch of your voice (at least non very much). Instead, it affects a much more mysterious property of the sound, called "timbre." Rather than chirping high notes like Tweety Bird, you lot showtime quacking words like Donald Duck.
Simply why does helium affect your voice with that reedy tone?
Outset, here'southward what's happening inside your throat when you talk: According to acoustics expert John Smith, a biophysicist at the Academy of New South Wales (UNSW) in Sydney, Australia, you lot generate sound past rapidly vibrating two small flaps of mucous membrane, called song folds, in your voice box. The back-and-along motions of these folds interrupt the flow of air from your lungs to create "puffs" of sound.
If your song folds wiggle dorsum and forth 100 times each second, they produce puffs with a frequency of 100 beats per 2nd (Hz). Additional motions of the vocal folds, such as collisions with each other, generate additional frequencies that are multiples of that cardinal frequency: "harmonics" at 200 Hz, 300 Hz, 400 Hz and and then on.
All these frequencies travel together through the vocal tract — the tubelike cavity leading from the vocalization box upwards through the throat and mouth to the outside world. Depending on its shape, this tract resonates with certain harmonics generated by your vocal folds, meaning it vibrates in fourth dimension with them. In doing and then, the vocal tract amplifies those resonant harmonic frequencies, making them louder.
And then, the harmonics created past your particular vocal folds paired with the shape of your item song tract produce a unique collection of resonant frequencies that, taken together, requite your voice its distinctive audio quality, or timbre. [The Physics of Loudmouths: Why Some Voices Carry]
That'southward where helium comes in. Audio travels one,128 feet per second (344 meters per second) through regular air, but it travels three,041 feet per 2d (927 meters per second) through helium gas. This is considering nitrogen and oxygen molecules that make up the bulk of air are much heavier than helium atoms, so they don't oscillate back and forth near as speedily. (That oscillating is what pushes the sound wave through the gas.)
In physics, the speed of a wave equals its frequency multiplied by its wavelength. Then, if a audio wave travels faster through a vocal tract full of helium than it would through a vocal tract total of air, either its frequency or its wavelength must get a heave in a helium-filled crenel, besides.
The wavelengths that resonate with the vocal tract depend only on its shape — i.e., the resonant harmonics are the ones whose consecutive peaks fit snugly in the vocal tract — so their wavelengths stay the same regardless of whether the tract is filled with helium gas or air. (Put differently, the gas molecules inside the tract oscillate back and forth the same distance regardless of what molecules they are.)
That ways thefrequencies of the resonant harmonics must increment in a helium-filled cavity instead. Co-ordinate to Smith and colleagues in "Physics in Speech," a reference article on the UNSW website, resonant frequencies are several times higher in a vocal tract filled with helium compared to one filled with air.
And that means sure high-pitch components of your voice become amplified relative to the low-pitch components, drastically changing the overall timbre of your vocalisation. "There is less power at depression frequencies and then the audio is thin and squeaky," the UNSW physicists write.
One might wonder why ducks always sound the way they exercise, despite animate regular air. According to the experts, "an articulate simply otherwise standard duck would have a shorter vocal tract than ours so, even while breathing air, Donald [Duck] would have resonances at rather higher frequencies than ours."
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Source: https://www.livescience.com/34163-helium-voice-squeaky.html
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