"The whole strata community owes a huge debt of gratitude to you and the OCN executive. Much appreciated."
2.2 What is sound?
Sound is produced by vibrating objects causes slight changes in air pressure. These air pressure changes travel as sound waves through the air and produce sound. The vibrations reach the listener's ears through air, liquids or solids as waves or vibrations of cyclical pressure fluctuations, similar to a stone dropped in a pool of water.