Hear Hear Objectives Identify the parts of the ear Describe how vibrations are transmitted and turned into electrical signals which pass to the brain. Key Words Cochlea Amplifies

How do we hear things? Draw a diagram to explain how the boy hears the bell

Sound Sound is produced when an object vibrates. This movement of air is passed onto the listener’s ear. Sound travels outwards in ALL directions from the source, it travels in waves. The source vibrates in such a way that the air around it is also made to move The number of vibrations per second is called frequency and measured in Hertz (Hz) Human ears can hear sounds between 20 and 20000 vibrations per second.

The frequency of the sound determines the pitch Sound travels in waves, this can be demonstrated using a sklinky.

Sound need a medium to travel through Solids Liquids gas

Where does sound travel fastest? Solid Particles Very Close together Liquid Particles close but not always touching Gas Particles very far apart

How do we hear?

Sound : The ear 1. Sound waves are collected by the ear lobe or pinna. 6. The auditory nerve takes the signals to the brain. 2. The waves travel along the ear canal. 3. The waves make the ear drum vibrate. 4. The small bones [ossicles] amplify the vibrations. 5. The cochlea turns the vibrations into electrical signals.

Sound : The ear 1.Sound waves are collected by the ear lobe or pinna. 6.The auditory nerve takes the signals to the brain. 6 4 1 2 3 5 2.The waves travel along the ear canal. 5.The cochlea turns these into electrical signals. 3.The waves make the ear drum vibrate. 4.The small bones (ossicles) amplify the vibrations.