The sounds that we hear are actually vibrations - sound waves - traveling through the air, but vibrations travel through all sorts of substrata.
Spiders use web vibrations to determine the location of prey.
Humans and other animals send vibrations in the air to chat.
Insects send plant-borne vibrations to find and attract mates.
Some insects use water surface ripples to communicate.
Whales send vibrations through the water to sing long distances.