Air needs a medium to get transmitted. If we slowly remove the air inside the bottle. Sound will not be having medium to travel as it will be the vacuum. Due to vacuum loudness of the sound decrease gradually with the quantity of the air in the bottle.
To travel, sound required a medium. Sound cannot travel in a vacuum because there is no medium to transmit sound waves.
- Sound needs a material medium for its propagation like solid, liquid or gas to travel because the molecules of solid, liquid and gases carry sound waves from one point to another.
- Sound cannot progress through the vacuum because the vacuum has no molecules which can vibra