Why Do You Hear the Ocean In A Seashell? - WorldAtlas

The ocean-like sound produced by a seashell is an interesting phenomenon.

Orca Species in Adventures in Valerick TTRPG

Listening through the world of a sea shell! – Sound Xplorer

Notes from the Field

Why Do You 'Hear The Ocean' In a Seashell? - Coastal Care

A world of Faith, Airships, and Iron: setting historia/eventual ME cross?: Proof-readers wanted, Page 36

Why can you hear the sea in seashells? - Fun Kids - the UK's children's radio station