When we hold a large seashell up to our ear, you can hear what sounds like waves because the shell echoes all the sounds around you. If you could listen to a shell in a completely soundproof room, you would hear nothing at all!
Many land snails can lift 10 times their own weight up a vertical surface. (If you were this strong, and you weighed 30 kg (about 70 lb), you could carry 300 kg (almost 700 pounds!!!) straight up a wall!