Ask Dr. Universe – Finger Snaps

Dr. Universe: Why does it make noise when you snap your fingers? – Amelia, Michigan, 12

Dear Amelia,
When I got your question, I snapped my fingers a few times to try and find the exact source of the sound. After a few tries, I decided to ask my friend Troy Bennefield, the director of Athletic Bands at Washington State University.
While we may start a snap with the top of our thumb and middle finger touching, he said that the snapping sound actually happens when the middle finger hits the palm area at the base of the thumb.
As the middle finger hits the base of the palm, you actually send some vibrations out into the air. Vibrations are a big part of the reason we can hear all kinds of things—from snaps to claps to a variety of musical instruments. 
When an object vibrates, it creates waves of energy that travel to a listener’s ears. The outer part of the ears collect those waves and the ear canals channel them inside of the ears. Meanwhile, the brain helps interpret the incoming information and allows you to put a name to the sound you hear.
You know, there are so many different sounds to hear in our world. Part of the reason a snap sounds different from a clap or a musical instrument like a violin or drum is that the objects are made up of different materials. The materials vibrate in slightly different ways, giving us all kinds of sounds to hear and music to make.  
Bennefield is really interested in how we can use snapping in making music. One famous scene with a lot of snapping comes from the musical “West Side Story.” Maybe you know a song or two that incorporates a lot of snapping, too. Think about how that sound can bring a certain emotion or feeling to the song.
Maybe you can even try some snapping experiments of your own. Try a snap in your right hand. Now try the left. Did you notice any differences? Now, try playing with some different rhythms. Snap at a nice, slow steady pace or pick up the pace for a quicker rhythm.
If you are up for the challenge, see how many snaps you can do in a minute. Record your results. Just a couple of months ago, Guinness World Records announced that the new world record for most snaps in a minute is 437 snaps.
Perhaps you can also experiment with the volume of your snaps. The loudest snap on record was recorded at 108 decibels. For comparison, a motorcycle makes sounds that are recorded at about 100 decibels.
Try a super loud snap or try to make the quietest snap you possibly can. Observe how the volume changes depending on how much force you create between your finger and your thumb.
Whether your snaps are quiet or loud, slow and steady, or super-fast, remember that the sound all comes back to those vibrations in the air.
Dr. Universe


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