Why can you hear the ocean when holding a seashell to your ear?

A conch shell on a beach. — As a child, listening to the ocean from a shell was exciting. WIN-Initiative/Neleman / Getty Images

Do you remember trying this as a kid -- Holding one of the seashells you grabbed as a souvenir up to your ear? It seems like no matter how far away from the ocean you are, you can still hold a seashell up to your ear and hear the roar of the waves rolling onto the shore. The best shells for producing this sound are the large, spiral conch shells.

Some people have suggested that the sound you hear from the seashell is the echoing of your blood rushing through the blood vessels of your ear. That is not the case. If that were true, then the sound would intensify after exercising, since your blood races faster after exercising. However, the sound is the same even after exercising.

Others say that the whooshing sound inside the shell is generated by air flowing through the shell - air flowing through the shell and out creates a noise. You'll notice that the sound is louder when you lift the shell slightly away from your ear than it is when the shell is right against your head. However, this theory doesn't hold true in a soundproof room. In a soundproof room, there is still air, but when you hold the seashell to your ear, there's no sound.

The most likely explanation for the wave-like noise is ambient noise from around you. The seashell that you are holding just slightly above your ear captures this noise, which resonates inside the shell. The size and shape of the shell therefore has some effect on the sound you hear. Different shells sound different because different shells accentuate different frequencies. You don't even need the seashell to hear the noise. You can produce the same "ocean" sound using an empty cup or even by cupping your hand over your ear. Go ahead and try it and vary the distance at which you place the cup near your ear. The level of the sound will vary depending on the angle and distance the cup is from your ear.

Noise from outside the shell also can change the intensity of the sound you hear inside the shell. You can look at the shell as a resonating chamber. When sound from outside enters the shell, it bounces around, thus creating an audible noise. So, the louder the environment you are in, the louder the ocean-like sound will be. For more information check out the links on the next page.

Hear Ocean in Shell FAQ

Why does it sound like the ocean in a seashell?

The unique shape of seashells amplifies the ambient sound, which means that any air that makes its way through the seashell produces sound when bounced about in the curved inner surface. The sound that is produced sounds ocean-like but isn't.

What is the sound you hear when you put a seashell to your ear?

Some people believe that the sound you hear when putting a seashell to your ear is that of your blood rushing though the blood vessels in the ear, but that is not true. It is the ambient noise that's produced when the air entering the seashell bounces about in the hollow cavity of the seashell.

What sound does a conch shell make?

The bouncing air inside a conch shell produces a unique sound which sounds just like the ocean.

Is it wrong to take shells from the beach?

It is okay for you to pick up empty shells that are lying around the beach because many wash up on the seashore by the ocean in a never-ending rotation. Picking up these shells does not disrupt the coastal ecosystem in any way.

What is the name of the shell in which you can hear the ocean?

Conch shells are the best at producing ocean-like sounds when put to the ears.

Why Can You Hear the Ocean When Holding a Seashell to Your Ear?