1) Sound is produced by vibrating objects like bells, drums, and musical instruments. Different musical instruments produce sound through the vibration of different parts like strings, membranes, and air columns. 2) In humans, sound is produced when air passes through the vocal cords in the voice box or larynx, causing them to vibrate. 3) Sound requires a medium like air, water, or solids to propagate from the source to the listener. It does not travel through a vacuum.