Episode 76: Voice Flame Extinguisher

Air Date: April 11, 2007

Sound waves can put out a flame.


A normal human voice cannot put out flames. An amplified voice, however, can put out a candle at low frequency while tone generators can extinguish propane flames. This can be done because the sound waves disrupt the air enough to snuff out the flame. Also, using a high explosive bomb can put out flames since the blast wave pushes away the oxygen that fuels the fire. Using explosives is a common method firefighters use to put out oil fires.

Using hypnosis can make one act against their will.


While hypnotized, Grant was told to do certain uncharacteristic actions through hypnotic suggestion, and he would perform these actions after a specific trigger. However, the triggers did not work, so the test was performed again on a producer who believed in hypnosis. However, this test also failed. In addition, many experts and hypnotists agree that hypnotic suggestion will never work if the suggestion conflicts with the subject’s moral fiber.

Using hypnosis can make one remember things more clearly.


The Build Team was given a short play and were later quizzed about minor events, in which they failed miserably. Taking the same tests under hypnosis, they remembered tiny facts such as name tags and tattoos and passed with flying colors. As a side note, "earthlings" who were "abducted" by "aliens" claim they don’t remember a thing unless under hypnosis.


  1. notak says:

    The amplified voice flame test in the sound wave experiment was invalid. The speaker which was moving air put out the flame due to proximity, not the actual sound waves.

    • MSpears says:

      Sound is nothing but waves in the air. Anything that makes sound is ‘pushing’ the air. Therefore, the experiment is still valid.

    • rand says:

      Wrong. Sound waves are transverse and actually do push particles in the air. Also, they are mechanical in nature (as opposed to electromagnetic waves that can travel in a vacuum) which means if there were no particles in the air, they would not be able to travel (this is why you can’t hear sounds travel in a vacuum like space, there is no particles for the wave to propagate through). This is just a very basic explanation for how and why this works, I would suggest if you have interest in this to go read some physics articles on sound waves, they are very interesting.

  2. scott says:

    The post Hypnotic suggestion segment was not well done. To prove it they should have used an entertainment hypnotist (there are a lot out there) in a setting where the volunteers had no idea about the show. Anybody who has seen a hypnotist show would say yes people can be made to do things after they are “awake”. But as the show, and legitimate practioners would say, people cannot be made to do things that are counter to their beliefs or moral fibre.

  3. Tamara says:

    I agree with you scott. A hypnotist came to my school a few years ago, and just before he woke up a group of about 40 people he told them that, when asked how they liked the show, they should say ‘I laughed, I cried, I loved it more then cats!’ until they heard music. I have to say, it was hilarious! But there were a few variations (A friend of mine, Tyler, said ‘I cried, I giggled, it was better then cats!’ for about an hour, because he left before the music started!)

  4. Buster says:


    Sounds waves are created by moving air. That’s the whole point.

    “The speaker which was moving air put out the flame due to proximity, not the actual sound waves.” Sound wave = moving air.

    • nile says:

      fan blades don’t convey any meaningful sound. neither do vibrating speaker cones move any measurable amount of air. normally.

      but perhaps when some circuit driving a speaker is initially turned on, a strong mechanical pulse, leading to a minute thrust of air is produced by the speaker cone.

      i didn’t see the show, but that could be what he’s talking about. it wouldn’t surprise me either. those guys are partial numb nuts.

      • nile says:

        in retrospect, and since i don’t understand the phenomena they were studying, i think my explanation is probably way off base.

  5. Norakism says:

    The experiment in which hypnosis was claimed to improve memory didn’t have a control.

    I often forget something and then remember it later in the shower. What if the subjects would have later remembered even without the aid of the hypnotist?

    It is a post hoc ergo propter hoc fallacy. Look it up on Wikipedia.

    • Allana says:

      i would like to point out that Wikipedia is not a valid argumentable source. that’s all.

      • MSpears says:

        I would like to point out that Wikipedia is considered more accurate than some encyclopedias. That is all.

  6. Nathan says:

    can you send me an e-mail with the info of the voice extingguisher. because at school we are doing a progect?scince-fear on carbiondieoxide and my grup would like to try it

    thank you

  7. nathaniel says:

    In my school we are doing a science fair, and I would like to try one of your myths. Can you give me some data about sound waves extingushing fire.


  8. Bryan says:

    in regards to sound and its ability to extinguish fire… you must first understand what sound actually is… and it is vibration of air molecules, more specifically the compression and rarefaction of air molecules… this action can create a “wind” effect at extremely high levels, but it varies on a few things, one of which most specifically is the size of the transducer (that which converts electrical (or some other energy) to mechanical energy)

    so to say that wind is putting out the fire is correct, but that “wind” is indeed the sound being created

    unfortunately it will be a difficult thing to test because of the fact that it is difficult to steer sound waves as there are mostly omni directional, so distance is the easiest way to control its dissipation

    i think finding an opera singer, one who controls the the “distance” of their voice would be far more beneficial than an A Capella group

  9. raz says:

    @ notak.. you are right
    I thought the same thing.
    The flame was placed 2 inches away from the speaker.
    the speaker was moving back and forth probably an inch and creating wind to put out the fire (more wind then noise).
    do the same thing but with the speaker 5 feet from the flame it wont budge

    Having said this.. I could move a car with speakers. place 50 speakers of I dont know 30 inches each and blast the volume and wow look at that.. I moved a car.
    broke all the windows around but look it moved.

  10. Charles says:

    On the subject of the trombone with the firecracker in the bell; the story you were trying to duplicate included the trombone player’s lips being burned, but when you set up the experiment I didn’t notice if you plugged the mouthpiece to simulate the player’s lips covering them. Could this have made a difference in the outcome?

  11. Ashley says:

    I tried this at home and it works you just have to be closer then you were. I’m actually doing a project on this ……. So fore me it worked i gess it depeneds were your standing and how low you can go with your voice….

  12. nathanield says:

    to all yo myth buster fans out there i am really happy because finality i agree with Adam and Jamie on the fire sound extinguisher myth

  13. Brian says:

    Here is an article in Time Magazine talking about Charles Kellogg’s voice made a gas flame “…flare up, turn from yellow to blue and roar.”
    The article goes on to say “Sufficiently intense vibrations would have extinguished the flame.”


    A change in color was not produced on the show, therefore, they are using the wrong frequency.

    When I find the frequency, I will post it all over the internet. Then, we will have smoke detector that actually extinguish the flame rather than just annoy everyone.

  14. Lorenzo says:

    I want to know what frequency the speakers were sending the sound waves, and what program can genarate that frequency.

  15. nollie says:

    im doing this but using a cars amp and spekers allong with a masive flame not a voice just a bass test(:

  16. Steve says:

    When in highschool I made a weak blue flame on a propane bench torch and put it out by clapping my hands from 15 feet away. I thought it was neat and tried it over and over and never thought much about it since. I was melting glass tubing and pulling it into super thin tubing and thought it would make a torch tip. I attached to the propane head with rubber tubing and taped over the air hole inlets. The flow was extremely low and the flame danced out from the tip 3 to 6 inches in the air. Clap, its gone.

  17. guillaume says:

    Sorry, i’m french (and french Love you :))

    (en francais si vous avez un bon traducteur)
    Je pense qu’une explosion éteint une flamme car elle consume l’oxygène, ce n’est donc pas l’onde de choc.

    I think an explosion burn the oxygene, it is not the shock wave whitch put out the flame.

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