Low Frequency music being harmful?

Discussion in 'General Science & Technology' started by Goodvibes, Aug 26, 2008.

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  1. Goodvibes Registered Member

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    Hi

    I recently read an article on how low frequency electromagnetic waves can be harmful as they have an ionizing effect at the genetic level, also high frquencies have a deleterious effect, with the range between 10 KHz and 10 GHz having a non-ionizing effect and therefor presumed fairly harmless.

    The artilce was in reference to mobile phones and how this safe bracket may not be as safe as we think as they operate slightly below the upper band.

    My question however is in reference to really low frequency music. ie. dubstep. Dubstep utilises the sub whoofer which emmits really low frequency notes and you can really feel it vibrating through your body when listening to it in a club. If you havent heard it search youtube and you will see.

    I read that dubstep tunes can contain frequencies as low as 35hz which seems to me to be in the ELF range below 10 KHz. I am wondering if this is bad for you when blasted out of massive speakers because of its low frequency, or am I missing something that explains how this is fine??

    Thanks
     
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  3. Fraggle Rocker Staff Member

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    Music is a sound wave, not an electromagnetic wave. Those are two entirely different types of vibration. In an electromagnetic wave, subatomic particles are vibrating, such as photons or electrons. In a sound wave, it's the entire molecules of the air (or other substance) that are vibrating. The two types of vibration do not have the same effect.

    Furthermore, what is considered a "low frequency" for an electromagnetic wave would be an extremely "high frequency" for a sound wave. A low frequency sound wave is at the lower threshold of human hearing, down below the low B-string on a five-string bass guitar, which is 30 Hz. A low frequency electromagnetic wave is measured in tens of thousands of herz. A sound wave of that frequency is beyond the upper threshold of human hearing.
    I've stood in front of the speakers at a rock concert in a moderate-size pavilion, and I could feel the bass notes vibrating my skin. That isn't half as bad as what loud high notes do to your ears. They kill the microscopic hairs that transmit sound and eventually make you deaf.
    Again, you're confusing sound waves with electromagnetic waves. The upper threshold of human hearing is typically 16-20kHz. 10kHz is a really high pitch. In music it's almost invariably heard only in harmonics, not in the fundamental tone of a note. That would be more than an octave beyond the highest note on a piano.
    Yes, you're missing the fundamental distinction between the mechanical energy in a sound wave of vibrating molecules, versus the energy in an electromagnetic wave of vibrating subatomic particles. Electromagnetic waves have frequencies that are as much as a million times faster than sound waves. So a "low-frequency" EM wave is not very low by the standards of sound waves. Look at your FM radio dial, the lowest frequency on it is 85 megaherz. X-rays, visible light, etc. are even several orders of magnitude (powers of 10) higher than that.
     
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  5. visceral_instinct Monkey see, monkey denigrate Valued Senior Member

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    No shit.

    I was in the nightclub once and for some stupid reason the DJ put on a song with these horrible high frequencies. Everyone in there swore and stuck their fingers in their ears.
     
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  7. Orleander OH JOY!!!! Valued Senior Member

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    Is the low frequency the whole brown noise thing?
     
  8. Fraggle Rocker Staff Member

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    "Brown noise" is short for "Brownian noise." It's generated by molecules engaging in Brownian motion, which was discovered by Robert Brown. It indeed has more power in the lower frequencies, with a decrease of 6db per octave. It's said to have a soft, damped quality.

    White noise is analogous to white light, with the same power at all frequencies.

    The power in pink noise is spread evenly logarithmically, so there is the same power in the range between 64 and 128 Hz as the range between 512 and 1024 Hz. Since humans perceive sound logarithmically (each doubling of frequency is one musical octave), pink noise sounds balanced to humans. 64 Hz and 128 Hz are the C two octaves below middle C and one octave below middle C. 512 Hz and 1024 Hz are one octave above and two octaves above middle C.

    Purple noise is just the opposite of brown noise, with power increasing 6 dB per octave.

    Blue noise is a less intense version of purple noise, with power increasing only 3 dB per octave.

    Grey noise is a random distribution.

    If your computer has the right software (mine doesn't), you can hear ten-second samples of these signals on Wikipedia.
     
  9. visceral_instinct Monkey see, monkey denigrate Valued Senior Member

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    Why the colours? Why didn't they call them red noise or black noise?

    and, thanks for the info Fraggle. That's pretty interesting.

    I always thought it was called brown noise because it made you lose control of your bowels.
     
  10. Fraggle Rocker Staff Member

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    They do have other colors. I just listed a sample.

    The specific color names were picked because in each case there's an analogy between the frequency spectrum of the sound wave and the frequency spectrum of the corresponding light wave. Green noise is right at the middle of the audible spectrum, just like green light is at the middle of the visible spectrum. The blues and purples are at higher frequencies, and the reds and oranges are at lower frequencies, just like the light.

    There is such a thing as "black noise." It's inaudible because it's all up in the frequencies above the audible range. Just like we call UV "black light."
    Don't thank me. I got most of that from Wikipedia, just like a lot of the stuff I post. You people should become more familiar with Wikipedia; I turn 65 soon and heck I might just decide to retire.

    Please Register or Log in to view the hidden image!

    I saw a reference to that, but I don't know if they were referring to it as an actual phenomenon or an urban legend from the undergraduate science laboratories.
     
  11. MetaKron Registered Senior Member

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    The "brown noise" that I know of comes from a South Park episode. Most likely someone ran across the term and said "Hey!" I had never heard of the real thing being called "Brown Noise" before.
     
  12. phlogistician Banned Banned

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    'Brown Noise' is an urban myth that low frequency sound can make you poo yourself.

    Debunked on Mythbusters, iirc.
     
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