Albert Teen

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Microphones

# Microphones

### Microphones

Microphones convert the pressure variations in sound waves into variations in current in electrical circuits.

What is it that microphones convert into an electrical signal?

So a microphone takes sound waves as input. What is it really that the microphone picks up and reacts to?

So a microphone converts changes in pressure into electrical signals. Which option best describes how loudspeakers and headphones work?

A microphone works by detecting the changes in pressure caused by sound waves and converting them to electrical signals. The opposite happens in loudspeakers and headphones. They convert electrical signals into changes in air pressure which produces sound.

Do all sound waves create the same changes in pressure?

Sound waves have different properties, like amplitude, frequency and wavelength. This means that they create pressure variations. If they didn't, we would only ever hear one sound!

So a microphone converts pressure changes caused by sound vibrations into electrical signals. How do you think it does that?

1

Which part of the microphone is the first part to move? So the part that causes the coil to move.

2

The diaphragm then causes the coil to move. The coil moves in a magnetic field. What will this induce across the coil?

3

The electrical signals change in size and direction as the coil moves in and out of the magnetic field.

The electrical signals that are generated by the coil's movements match the pressure variations caused by the sound waves.

Microphones convert changes in pressure to generate electrical signals. This is an example of the generator effect. The electrical signals generated match the pressure variations caused by the different sounds.