How does the sound get from the outer ear to the inner ear?

Soundwaves travel through the air and the ear flap directs the sound into the ear canal. the ear canal takes it to the ear drum, the ear drum vibrates, hitting the hammer which moves the anvil then, the stirrup acts like a piston.

Sound is caused by oscillations in matter. The frequency, tone, ect. are based on the material, it's mass, it's density, and many other factors. Oscillations in matter, which are cause by a force or transfer of energy, travel as waves and as such need a medium in which they transfer. If someone were to slam their hand on a desk; this is what would happen: The forced vibration in the table would attempt to travel in all directions and the wave would hit every particle all around it. Once the energy from the eave has been transfered it need to transfer elsewhere and so it hits another particle which hits another which hits another in a domino like effect. The ear is designed to picked up these vibrations in the ear from every angle and so it does. The energy flows into the ear and hits the ear drum, which transmits the sound through bone called "ossicles". The energy continues to flow down into the middle ear . The Cochlea, which is fluid filled, receives vibrations from the ossicles and the air in the middle ear. The fluid is thus set into motion from different angles and the mechanical energy from the fluid flows against thounsands of tiny hairs (or hair cells). The hair cells then convert this mechanical energy into electrical energy via neurotransmitter (chemical) to nerve cells (Vestibular cochlear nerve). The information from the elctrical pulses are picked up by the brain and the brain determines the frequency, pitch, volume, tone, timbre, distortion level, and direction of sound. The brain then reproduces the sound in your head. Amazing really...

Also, the fluid in the Cochlear also gives you a sense of balance. When you turn your head to one side; the fluid flows to on side which displaces the tiny hairs. Try turning your head to one side and you'll feel what I'm talking about.