Here is a description of how hearing, tasting, and smell work. Sounds waves travel from the air to our ears. While in the ear, they go through small tunnels about 25 ml long to the eardrum which vibrates and causes us to hear. We taste things because our tongues are covered with thousands of tiny bumps called taste buds. Taste buds on different parts of our tongue cause us to taste sour, bitter, salty, sweet and bitter. Food chemicals make our taste buds work, and nerves in our tongue send messages to our brain to let us know what we are tasting. The sense of smell occurs because the nerves inside our nose bring messages to our brain about what we are smelling. Our brain lets us know what we have smelled.