Sound in water and sound in air are both waves that move similarly and can be characterized the same way. Sound waves can travel through any substance, including gases (such as air), liquids (such as water), and solids (such as the seafloor). In fact, sound cannot exist if it doesn’t have something to travel through! For example, sound cannot travel through outer space because it is a vacuum that contains nothing to carry sound.
Something else that’s interesting in the differences between sounds in water vs. through the air is how vowels and consonants sound. The next time you’re in a pool with friends, duck your head under water and listen to their conversation. If they talk loud enough, you’ll hear the vowels–a, e, i, o, and u, but not the consonants. Therefore, some words won’t make sense.
Sound travels very well under water, but some sounds have more trouble getting from the air into the water. But why the vowels and not the consonants?
Water waves and Sound waves
Every spoken sound is actually a combination of different sounds, some low, some high. Even though we don’t notice the different sounds, the way they’re combined is what gives each spoken sound its own character.
In general, consonants contain higher pitched sounds than vowels. Those are sounds made of faster, smaller sound waves. Compared to consonants, vowels are mostly made of low pitches. In other words, they’re made of larger, slower sound waves.
From Ping Pong balls to Basketballs
When small sound waves hit the uneven surface of the water, they get scattered in all directions, like ping-pong balls landing on a rough road. The much larger, lower pitch waves are not affected as much by the small water waves because they hit a much wider area on the water’s surface.
If we think of a small sound wave as a little ping-pong ball on a rough surface, a larger sound wave is more like a big basketball, which is less affected by little bumps on the road. Unlike balls bouncing on a road, sound waves pass through the water. Knowing these differences between how various sounds travel is helpful because it underscores the complexity of not just sounds, but how our hearing is affected too.