1. Speaker: A device that converts electrical signals into sound http://www.hometheaterhifi.com

2. What is electricity? A form of energy A form of energy Non-static electricity is the movement of electrons, usually in a wire Non-static electricity is the movement of electrons, usually in a wire http://catalog.pitsco.com

3. What is a sound wave? A pressure wave traveling in a medium A pressure wave traveling in a medium Air molecules get compressed and as the air molecules spread out, they in turn compress the adjacent air causing the sound wave to continue. Air molecules get compressed and as the air molecules spread out, they in turn compress the adjacent air causing the sound wave to continue.

4. Electricity creates a magnetic field Current is the flow of Electrons I = electrons/time

5. A changing magnetic field creates electricity in a wire www.physics.uiowa.edu

6. Electricity and Magnetism are related A moving/changing magnetic field can produce current. A moving/changing magnetic field can produce current. Moving electrical charge (current) can produce a magnetic field. Moving electrical charge (current) can produce a magnetic field.

7. How does sound vibration get converted into electrical signals? Electrical current corresponds to the pattern of the sound wave. Sound vibrates diaphragm, which moves coil This device is commonly called the Microphone

8. How do electrical signals get converted back into a sound wave? This device is commonly called a Speaker When an electrical signal from an amplifier is sent to the voice coil, a magnetic field is set up around the coil. The permanent magnet in the speaker will push and pull on the coil in a way that matches the incoming electrical signal. The coil is attached to the speaker’s cone. As the cone moves and vibrates, a sound wave is created. www.speakers.net/images