How speakers and microphones work

How speakers & 8 { microphones work An electrical signal passes into the wire coil. Permanent magnet Current flowing through the coil generates a magnetic field around it. It experiences a force from the permanent magnet, making it move. Wire coil The current changes size and direction, which makes the magnetic field around the coil change, and so changes its movement. Diaphragm The diaphragm moves with the coil, passing on vibrations to the surrounding air, which we hear as sound. Speakers turn electrical signals into vibrations Microphones turn vibrations into electrical signals A sound causes the air to vibrate. This makes the diaphragm vibrate. This moves the coil up and down relative to the permanent magnet, which generates a current in the coil. The current in the coil changes in a way that reflects the vibration of the original sound. http://bit.ly/ThingsWStuff Microphone Speaker