Helium

[Botch.]

It's an engineer thing, you wouldn't understand.

 

Don't you have some press releases to write or something?

 

[KenElevenShadows]

Okay, now, would a room filled with helium in Denver sound really different than a room filled with helium in San Diego?

[Jeff Klopmeyer]

Well, the San Diego room would be more laid back, and perhaps smell like a leftover fish taco. Other than that, calculating the speed of sound at various elevations, and taking into account the density of the sea air and possible humidity level of the season in which the comparison is being made...

 

... WHO FREAKIN' CARES! Sweet mother of God, Go strum a guitar and write a song or something, fer cryin out loud.

 

 

- Jeff

[KenElevenShadows]

Originally posted by Jeff Da Weasel:

... WHO FREAKIN' CARES! Sweet mother of God, Go strum a guitar and write a song or something, fer cryin out loud.

 

 

- Jeff

Well, I'm actually just about to do a vocal recording session. And not just any one, but one that I played guitar on earlier.

 

But you know, Jeff, these are the things that keep me up late at night. Look, *someone* has to care. You know what I can do is start a whole separate thread about this Denver/San Diego helium thing and ask Bruce Swedien!!

[Dennyf]

For electric guitar, the pitch would be the same.

 

The voice is higher because of the way the larynx works. Vocal "cords" aren't really cords, they're muscles controlling the tension on an elastic slit aperture. The lungs push air through the slit, causing the vibrations that produce the voice, much like stretching the neck on a balloon laterally, letting air escape slowly to produce a buzzing noise.

 

The reason the voice is higher when breathing an exotic heliox mix, or abusing helium balloons is because helium is a much lighter gas than the typical "air" mix, which not only causes the fundamental tone of the voice to be higher, but changes the whole resonant character of the voice as well. But that's a product of the lighter gas *generating* the sound by being forced through the larynx, not a propagation-related property of the gas.

 

Now a speaker vibrating at 1000 cycles per second is producing a 1000hz tone in whatever medium it happens to be in. The speed of propagation may be different for different media, i.e. it may travel faster or slower than 1100 feet per second (as it does in "air" at sea level), but regardless of how long it takes to get to your ear from the speaker, it's still gonna be a 1000hz tone. And sound at 1000hz.

 

Some pools have music piped under the water. Sound propagates 'way faster in water, yet the music still sounds the same underwater in the pool. The only difference is that you loose directionality because there's not enough difference in time between when the sound reaches each ear.

 

And I didn't even use a slide rule.