Singing In The Rain

[Robert Booth]

Yesterday over lunch our school choir director mentioned in passing that an a cappella choir will tend to sing flat in wet weather, more so than in fair weather.

 

Have any of our singers, players noticed this, and could they maybe have some explanation as to why this might be so?

 

Idly curious,

Robert

[Leo]

Robert

 

Idly thinking it has to do with the density and the composition of the air, and the absorbtion of the complicated sound waves of the voice by the soft drops of water.

 

Cold air is more dense, sound travels faster; warm air, sound travels slower. Moist air less dense than dry air, similarly temperature and pressure would effect the absorbtion and transmission of complicated sounds. The effect is similar to the "quiet" after a snowfall.

 

Here is the complicated version under "Attenuation of sound in air": http://www.kayelaby.npl.co.uk/general_phys...of_sound_in_air

 

Therefore everybody sounds good in the shower.

 

Thanks

Leo

[Peter Stephenson]

Robert and Leo.

 

Wonderful question, Wonderful elegant reply.

Would'nt it be nice if all the C-netters agreed ?

But I fear there may be some other options, remember the fan noise debate ?

[Leo]

Robert and Leo.

 

Wonderful question, Wonderful elegant reply.

Would'nt it be nice if all the C-netters agreed ?

But I fear there may be some other options, remember the fan noise debate ?

Peter

 

A little before my time, but I read a lot.

You might be right.

 

Thanks

Leo

Edited September 28, 2007 by Leo

[m3838]

Robert and Leo.

 

Wonderful question, Wonderful elegant reply.

Would'nt it be nice if all the C-netters agreed ?

But I fear there may be some other options, remember the fan noise debate ?

Peter

 

A little before my time, but I read a lot.

You might be right.

 

Thanks

Leo

But why moist air is less dence than dry? I would think the opposite is true.

If sound travels faster in cold air, why does it affect the pitch?

And why tiny droplets of water, suspended in the air, would affect the pitch? They may contribute to sound dying sooner, or adding muffling effect, but pitch?

Could it be that moist air deposits layer of water on vocal chords, and makes them slightly thicker, thus lowering the pitch?

[Mark Evans]

Would'nt it be nice if all the C-netters agreed ?

But I fear there may be some other options, remember the fan noise debate ?

 

Anything but that. Jumpin' Gehosiphat that was horrible.

 

One might consider the energy level that at least in my case is lowered by humid, warm air.

 

I can tell you it's not fun to be in a group and hear the pitch head south. Raise your eyebrows as yee might those headed yon way will continue. A group headed sharp ain't no ride in the park either.

Edited September 28, 2007 by Mark Evans

[yankeeclipper]

Cold air tends to contract certain male anatomical parts, resulting in higher vocal pitch.

[Peter Stephenson]

Ok

 

Does the chior actually sing flat, or does the listener only percieve them singing flat.

And do the singers hear themselves singing flat and overcompensate by singing sharp ?

etc..

[Mark Evans]

Well, then I'm in real trouble for short my comings are far too evident already!

Edited September 28, 2007 by Mark Evans

[Leo]

Gosh I didn't mean to hijack a thread. Sorry!

 

Think on the molecular level; density and volume (not pressure). Water vapor and droplets separately.

 

........It may seem reasonable to try to argue against that simple fact based on the observation that water is denser than dry air... which is certainly true, but irrelevant.

 

Solids, liquids and gasses each have their own unique laws, so it is not possible to equate the behavior of liquid water with the behavior of water vapor.

 

The ideal gas law says that a certain volume of air at a certain pressure has a certain number of molecules. That's just the way this world works, and that simple fact is expressed as the ideal gas law, which was shown above in equation 1.

 

Note that this is the gas law... not a liquid law, nor a solid law, but a gas law. Hence comparisons to a liquid are of little help in understanding what is going on in the air, and may simply result in more confusion.

 

According to the ideal gas law, a cubic meter of air around you, wherever you are right now, has a certain number of molecules in it, and each of those molecules has a certain weight.

 

Most of the air is made up of nitrogen molecules N2 with a somewhat lesser amount of oxygen O2 molecules, and then other molecules such as water vapor.

 

Since density is weight divided by volume, we need to consider the weight of each of the molecules in the air. Nitrogen has an atomic weight of 14, so an N2 molecule has a weight of 28. For oxygen, the atomic weight is 16, so an O2 molecule has a weight of 32.

 

Now along comes a water molecule, H2O. Hydrogen has an atomic weight of 1. So the molecule H20 has a weight of 18. Notice that a water molecule is lighter weight than either a nitrogen molecule or an oxygen molecule.

 

Therefore, when a given volume of air, which contains only a certain number of molecules, has some water molecules in it (which are very light weight), it will weight less than the same volume of air without any water molecules.

From here: http://wahiduddin.net/calc/density_altitude.htm

Any pilot types or weather guys here??

______________________

My understanding is the voice has many components both high and low. The droplets of water (as opposed to vapor) absorb the higher pitched components with the net result is slightly lower pitch.

 

Thanks

Leo

Edited September 28, 2007 by Leo

[Greg Jowaisas]

How about falling barometric pressure and its affect on the eardrum?

 

Perhaps the "problem" lies within and not without?

[Peter Stephenson]

Greg

It's got nothing to do with falling barometers, What Leo just said is clear enough.

[Leo]

Greg

It's got nothing to do with falling barometers..............

Peter

 

Thank you

 

If the ear were a sealed system like a barometer, or vacuum flask I might agree with Greg. The ear is a self equalizing system through the eustachean tube in the throat. Even when blocked with a cold, it's not noticed unless the sinuses were blocked, and then a good sneeze would cure that.

 

Also the rate of change of a barometric pressure from day to day doesn't vary much, unless a body were in the middle of a tornado. The limits are generally 27Hg on the low end to 31 Hg on the high end. Sorry I don't have the Mb equivalent at hand for our non US friends. There would be a greater rate of change going up in an elevator in a tall building.

 

Thanks

Leo

Edited September 28, 2007 by Leo

[Robin Madge]

I have noticed that I perceive a non-existant change in pitch if I yawn, when the ear becomes a temporarily closed system and cannot compensate.

Dare I ask how interesting was the singing?

 

Robin Madge

[spindizzy]

Yesterday over lunch our school choir director mentioned in passing that an a cappella choir will tend to sing flat in wet weather, more so than in fair weather.

 

Have any of our singers, players noticed this, and could they maybe have some explanation as to why this might be so?

 

Idly curious,

Robert

 

As a physicist, I started composing my techy reply....

but others got there first (BTW flutes play flat after after a draught of cold gassy beer ... denser air).

 

But as a street choir singer ... maybe it's just depressing, singer in the cold and wet

[JimLucas]

But why moist air is less dence than dry? I would think the opposite is true.

The number of "molecules" (including free atoms) per unit volume of a gas at a given temperature and pressure (for ordinary temperatures and pressures) is a constant, regardless of the kind of molecule. Dry air consists mainly of diatomic oxygen (molecular weight about 32) and diatomic nitrogen (molecular weight about 28), with a little argon (atomic weight about 40) and carbon dioxide (molecular weight about 44), and only traces of other molecules. In moist air, water molecules (molecular weight about 18) don't add to those heavier molecules, but displace some of them, so the weight density is less (though the molecular "particle" density remains constant).

 

Edited to add "of a gas".

Edited September 28, 2007 by JimLucas

[Peter Stephenson]

Hi jim lad

 

This is the Jean Kelly link Check out toe comment from crabb18

 

[asdormire]

Guys, this sounds too much like work, where I just left.

 

Alan