How does an audio signal travel through a wire? What format is it in? How is it encoded? How are microphones different from pickups on an electric guitar?Electricity. Electric. Electricity. Microphones use a diaphragm, pickups are just directly connected.
A microphone has a diaphragm which vibrates when sound waves hit it. The vibrations vibrate a permanent magnet which has wires wrapped around it. A magnet moving near wires induces a current. At the other end you have a speaker which has electrical wires wrapping around a permanent magnet. The current near the magnet induces vibrations. The magnet is connected to a diaphragm which vibrates the air creating sound waves.