Sound travels when the molecules in the medium ear drum transmit cochlea( medium, ear drum, transmit, cochlea ) vibrates. The closer the molecules are, the faster slower more curved( faster, slower, more curved ) sound travels. The fastest medium is a solid liquid gas vacuum( solid, liquid, gas, vacuum ) while sound does not travel in a vacuum solid liquid gas( vacuum, solid, liquid, gas ). In the ear, a vibrating object e.g. a trumpet produces waves. Sound then travels from the medium vacuum air ear( medium, vacuum, air, ear ) (air) to the ear. The vibrating air enters the ear, fuelled to the ear canal optic nerve cochlea ossicles drum( ear canal, optic nerve, cochlea, ossicles, drum ). The vibrating air sets up vibrations in the ear drums ear canal auditory nerve vacuum cochlea( ear drums, ear canal, auditory nerve, vacuum, cochlea ). The ear drums then transmit the vibrations to the small bones called ossicles cochlea ear canal ear drums( ossicles, cochlea, ear canal, ear drums ), causing them to vibrate. The cochlea ear drums ossicles vacuum auditory nerve( cochlea, ear drums, ossicles, vacuum, auditory nerve ) vibrates. These vibrations are detected by the hair lining and the auditory nerve cochlea ear drums ossicles ear canal( auditory nerve, cochlea, ear drums, ossicles, ear canal ) will then detect these vibrations and send the impulses to the brain.