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The Electrical Representation of Sound

Sound waves are converted from waves of air pressure to waves of electricity, and eventually back to acoustical energy. An audio signal is an electrical representation of a sound in the form of a fluctuating current. When a sound wave is translated from acoustical energy to electrical energy, it still is the same wave. The signal voltage/current fluctuates at the same rate as the acoustical energy and the signal level is proportionate to the amplitude of the original sound wave.

Four properties of electricity: Voltage, current, resistance, and power.

Voltage: Basically electrical pressure, it is hte force that causes the current to flow the the electronic circuit. Voltage is measured in volts (imagine that)

Current: Current is the flow of electrons from one atom to another. Metals and other materials with loosely bound electrons are called conductors, where as materials like rubber are called insulators. Current is measured in Amps. In a DC (Direct current) current, the electrons flow in only one direction; from negative to positive. AC (alternating current) current switches back from positive to negative many times a second. This current is very helpful in audio because the up and down behavior resembles the nature of the alternating compressions and rarefractions in sound waves.

Power: Power is voltage*current, and is measured in watts. It is the measurement of the amound of energy expended.

Resistance: Resistance allows us to use electrical current. It is how much material resists the flow when voltage is applied to the current. Conductors have little resistance, insulators have a lot. It is measured in Ohms.