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can we make a sound inaudible by another sound but with the same frequency?

for example.let us suppose that a car engine is working and it makes a sound like others.i want to make the sound inaudible with a wave which it's frequency is as same as engine sound.please help me

10 Answers

  • 1 decade ago
    Favorite Answer

    Yes, its possible. This technology is used in some Saab 2000 airplanes to reduce the noise of the turboprop engines especially in the rear part of the plane behind the wings and engines. Its called Active Noise Control.

    In the walls are several speakers and microphones hidden and a special electronic device uses the information it gets from the mics and calculates in real time the corresponding anti-wave form for the corresponding speakers.

  • 1 decade ago

    Don't know the answer, but as an interesting side note - there was a theory (or maybe it came out of some Tom Clancy book) that during the cold war, the Russians had developed technology like that to use in a torture chamber. The concept was that, any noise you made in this room - be it pounding on the walls, yelling, screaming, whatever - would be instantly recorded and played back to cancel out the sound, and you eventually would go insane. Doesn't sound too plausible, but it's an interesting idea.

  • 1 decade ago

    Yes! It is possible and it is already in development by a company that built this sort of device to reduce the amount of noise a computer fan makes.

    The device is built from a few microphones that sample the sound from different locations, a small electronic unit that analyzes the data and breaks down the sound to harmonic frequencies and a speaker that produces an exact opposite of that sound and transmits it.

    Because most noise is built up of a lot of different frequencies this is quite difficult to accomplish. When the noise is rhythmic or at least more or less constant it becomes easier to negate it.

  • 1 decade ago

    It is theoretically possible.

    As a club Dj with over 20 years of experience I can use an example from that. If you play the same record on both turntables (or CD players if you're a chump) at precisely the same point and make minute adjustments the the two will phase, many times highlighting certain frequencies, and eliminating others. It is usually the bass frequencies that phase the hardest, often with the kick disappearing entirely.

    Hope that helps.

  • 1 decade ago

    I would assume that since a specific frequency, being the actual wave and length, would not cancel each other out but would increase the volume of the given freq. Especially in your example because there is going to be more than just one audible sound wave given from the engine, being able to match them up would not cxl them out but intensify them... I think??

  • 1 decade ago

    it is possible.

    well the phenominan ur talking about is known as interference. u remember the law " energy can neither be created nor be distroied but it can be transformed...." this law is applicable here also. a scientist named THOMAS YOUNG carried out a similar experiment but he used highly monochromatic beam of light. u will also need highly monochromatic sound waves. what actually happens is that there is distribution of energy.

    in that experiment the result was at one place there was light of double intensity where as at the other place it was complete darkness.

    so it may be very mush possible in lab atleast.

    you may see a pic of the experiment on this link.

  • ceprn
    Lv 6
    1 decade ago

    I think so - you just have to have them halfway out of phase, so that the peaks of one coincide with the valleys of the other. they shoud cancel out??? The problem would be that you'd need a consistent sound for this to work, and most sounds in the world are not consistent.

  • Anonymous
    1 decade ago

    it is virtually impossible because you'd need to completely isolate the direction in which the engine is emitting sound. It's very hard to keep sound waves from spreading everywhere.

  • 1 decade ago

    This is how noise cancellation headphones work. The technology is not perfect but it does reduce the volume somewhat.

  • sphinx
    Lv 4
    1 decade ago

    its summer break its bn a while since i last revised my abt a moving source and using the doppler effect stuff...

    also tc of time cz they might end up interfering constructvely or destructively (considering fixed sources) calculate ur velocity, source distance... tc of ur time and sort things out

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