By now it's well-known that you don't actually hear the ocean when you put a seashell up to your ear, which is sad because the idea of listening to a seashell to hear the ocean is actually pretty cool.
What would even be cooler is being able to listen to your favorite radio stations right out of a seashell. Unlike the concept of hearing the ocean, listening to the radio is actually possible and you can thank the staff at Japanese radio station BayFM for that.
The seashell radios are made from real actual seashells called sazae (turban shells). The Sazae Radio works without any cables except for when it needs to be charged with the USB cable it comes with.