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.
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.
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.