Ear

• Sound waves that reach your ear drum can cause it to vibrate
• When the ear drum vibrates, the vibrations are passed on to tiny bones in your ear called ossicles, through the semicircular canals and to the cochlea.
• Pitch refers to how high or low a note sounds. It depends on the speed at which the sound waves move past our ears.
• The cochlea is the organ of hearing in the inner ear. It is a spiral-shaped structure that is lined with hair cells.
• The cochlea turns the vibrations into electrical signals which get sent to your brain and allow you to hear sound
• sound waves are reflected by hard flat surfaces. echoes are reflected sound waves