Humidity

Discussion in 'Trumpet Discussion' started by Jurandr, Feb 29, 2008.

  1. Jurandr

    Jurandr Pianissimo User

    183
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    Feb 23, 2008
    Illinois
    All the time I see things like "why don't you sleep with a humidifier" and the likes. Just wondering, how does humidity affect playing?
     
  2. oldlou

    oldlou Forte User

    Age:
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    Grand Rapids, Mi.
    Sleeping/living in a dry environment is prone to drying out the lips and causing cracking. Need I go farther?


    OLDLOU>>
     
  3. Firestas'1

    Firestas'1 Piano User

    471
    1
    Dec 21, 2006
    New Jersey
    Not to mention the throat, windpipe etc. I've been combatting dryness problems all week. My skin / lips are so dry and tight I can barely play anything at times.
     
  4. rowuk

    rowuk Moderator Staff Member

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    Trumpets are easier to play when they are moist inside too - regardless of external humidity.
    The speed of sound changes with the density of the air. Who has studied enough physics to present a formula. I looked and can't find mine.
     
  5. et_mike

    et_mike Mezzo Forte User

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    Oct 16, 2007
    Chesapeake, VA
    The speed of sound changes with the temperature and a little bit with the humidity, but not with the air pressure.

    Air Density Calculations

    First, consider the ideal gas law:

    (1) p × V = n × R × T

    p = pressure, pascals (multiply mb by 100 to get pascals)
    V = volume in m3
    n = number of moles
    R = gas constant
    T = temperature K = °C + 273.15

    Density D = ρ is the number of molecules of the ideal gas in a certain volume.
    In this case a molar volume, which can be mathematically expressed as:

    (2) D = ρ = n / V

    D = ρ = density in kg/m3
    n = number of molecules
    V = volume in m3

    By combining the previous two equations, the expression for the density D = ρ becomes:

    (3)

    D = ρ = density in kg/m3
    p = pressure, pascals (multiply mb by 100 to get pascals)
    R = gas constant = 287.05 J / (kg · K) for dry air
    T = temperature K = °C + 273.15

    As an example, using the standard sea level conditions of P = 101325 Pa and T = 15 °C,
    the air density at sea level, can be calculated as:

    D = ρ = 101325 / (287.05 × (15 + 273.15)) = 1.2250 kg/m3

    This example has been derived for the dry air of the standard conditions. For real-world situations,
    it is necessary to understand how the density is affected by the moisture in the air.

    The density D = ρ of a mixture of dry air molecules and water vapor molecules can be expressed as:

    (4)

    D = ρ = density in kg/m3
    pd = pressure of dry air in pascals
    pv = pressure of water vapor in pascals
    Rd = gas constant for dry air = 287.05 J / (kg · K)
    Rv = gas constant for water vapor 461.495 J / (kg · K)
    T = temperature K = °C + 273.15

    To determine the density of the air, it is necessary to know the actual air pressure,
    also known as absolute pressure, or station pressure, the water vapor pressure, and the temperature.

    Calculation of the wavelength with frequency and temperature
    Speed of sound - temperature matters, not air pressure
    Calculation of the wavelength of radio waves and acoustic waves

    The speed of sound in water is approximately 1500 m/s. It is possible to measure changes
    in ocean temperature by observing the resultant change in speed of sound over long distances.
    The speed of sound in an ocean is approximately:

    c = 1449.2 + 4.6 × T - 0.055 × T2 + 0.00029 × T3 + (1.34 - 0.01 × T) · (s - 35) + 0.0163 × z
    T = temperature in degrees Celsius
    s = salinity in parts per thousand
    z = depth in meters


    Have fun!!! :D
     
  6. rowuk

    rowuk Moderator Staff Member

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    et_mike: awesome!
    Now, where is it easier to play a double C?

    I found a little less technical version too:

    http://www.rane.com/pdf/eespeed.pdf

    Here you will also find out why you sound different on two different days...............
     
  7. Jude

    Jude Piano User

    318
    1
    Dec 2, 2007
    Density can be changed in two ways - by increasing the pressure (which increases velocity) and by altering the composition (changes appear to depend on both molecular mass and geometry - so no simple formulas).

    Equation 1 in the reference you provided accounts for the effect of composition, pressure and temperature (via density): c = √(γP/p), where c is the speed of sound, gamma depends on molecular geometry, hence composition, P is the ambient pressure (apparently in atm), and p is the density. After the first equation, P falls out, so the author must be restricting his discussion to P = 1, which is reasonable, since barometric changes are relatively small, and changes in their square roots thus negligible.

    All other things being equal, lighter molecules are easier to move, so replacing some O2 and N2 with lighter H2O (increasing the humidity) would speed up the transmission of the energy, the speed of sound.
     
    Last edited: Feb 29, 2008
  8. c.nelson

    c.nelson Pianissimo User

    139
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    Apr 13, 2007
    Alberton, Montana USA
    Trumpet players work better when they are moist inside....


    In the modern world, we tend to focus on the external,
    to a greater extent...


    Think about drinking enough water,or getting enough
    oils (olive oil,fish oil) in your diet.

    Too much salt can dry you out,as well.

    The human body does a good job of
    regulating itself, if you take care of it.

    Overall health has a lot to do with ALL your body's
    regulatory systems.


    peace:-)
     
  9. RG111

    RG111 Piano User

    331
    2
    Nov 12, 2003
    Our heat is gas furnace which is DRY. I have been suffering from a cough and dry chops all winter. Two days ago, we bought a room humiifier , and can't believe the difference! The mouthpiece is comfortable sitting on the chops again! A humidifier and Chop Saver are a great team!

    Roy Griffin
     
  10. mrmusicnotes

    mrmusicnotes Piano User

    307
    3
    Nov 11, 2007
    N.Y.C.
    dried and cracked lips leak and dont seal like moist supple lips. LCLR=Leaky chapped lips(raisins) MSLG=moist supple lips(grapes)
     

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