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What is Voltage [Audio Physics for Beginners]

Audio Basis - articles about audio

In this article, you'll read simple explanations what is voltage, in the context of audio physics. Keep reading.

Author: Yuri Korzunov,
Audiophile Inventory's developer with 25+ year experience in digital signal processing,
author of the articles that make audio easy for beginners
What is Voltage


What is electricity

Electricity is a field that can move electrons (charged particles).

Let’s imagine electrons as small balls.

The field is a difference between some levels of voltage.

The difference creates a mechanical force that moves electrons.



What is electrical voltage

Let’s look example that is well-known to everybody.

If a ball is lying on the ground, it has zero voltage.

If we lift the ball under the ground, we can consider as «voltage» a difference between the lifted ball and one on the ground.

Voltage is the potential of an electron,
like the potential of a ball that is held in hands above ground

Voltage audio signal



If we release the ball, it falls to the ground due to the «voltage». And the ball beat ground.

If we lift the ball upper than before, it will punch the ground harder.

So upper position has a higher «voltage».

In the example, you may replace the gravitation with an electric field.

Voltage is called U.

Usually, an audio signal is considered as an altering of the voltage in the time.

Changing the voltage of the audio signal in time.

Voltage in time


Frequently Asked Questions

Is audio signal voltage or current?

Voltage and electrical current are linked things. Voltage growth causes a rise of current and vice versa.

Some power sources are voltage sources. They generate a set voltage. Their inner resistance (impedance) is low.

Other ones are current sources. They generate a set current. Their impedance is high.

As rule, in audio, we operate voltage sources.


Is audio signal DC or AC?

Audio signal is electical analog of acoustic oscillations.

Audio signal is an electical signal. It is generated due to impact of acoustic wave to microphone. The acoustic wave is oscillation. Thus, the electrical signal is oscillation too.

Audio signal is alternating current (AC).


In the next articles, we will consider step-by-step how voltage relates to sound.

Electric current >