Microphone and speaker

The idea

A microphone converts sound energy to electrical energy as sound waves vibrate a thin diaphragm; a speaker does the opposite, an electrical signal vibrating a cone or diaphragm to produce sound.

Two devices, two jobs

A microphone and a speaker each have a part inside that vibrates. One is used to record a singer. The other lets an audience hear.

How do you think a microphone and a speaker are related?

• They do opposite jobs
• They do the same job
• Neither of them involves sound

Match them

Tap an item on the left, then what it does on the right.

Opposite jobs

A microphone turns the vibrations of sound into an electrical signal. A speaker turns an electrical signal back into vibrations that we hear. If all the parts work properly, the sound from the speaker closely matches the sound that was captured.

A microphone converts sound energy to electrical energy: sound waves make a thin diaphragm vibrate, and the vibrations become an electrical signal. A speaker does the opposite: an electrical signal makes a cone or diaphragm vibrate and produce sound.

Notes

A microphone turns sound energy into electrical energy. A speaker does the opposite: an electrical signal makes a cone or diaphragm vibrate to produce sound.

Check yourself

What does a microphone do?

What does a speaker do?

In a microphone, what do the sound waves make vibrate?

All the parts of a speaker are working properly. How does its sound compare with the sound that was captured?

• Converts electrical energy to sound energy. That is what a speaker does. A microphone does the opposite.
• Converts sound energy to electrical energy — correct. Yes!
• Stops sound from spreading. A microphone captures sound by converting sound energy to electrical energy.
• Uses sound to make an electrical signal. That is what a microphone does. A speaker does the opposite.
• Makes a vacuum so that sound cannot travel. A speaker produces sound. An electrical signal makes its cone or diaphragm vibrate.
• Uses an electrical signal to make a cone or diaphragm vibrate and produce sound — correct. Yes!
• A thin membrane called a diaphragm — correct. Yes!
• The electrical signal itself. The sound waves make a thin diaphragm vibrate. The vibrations are then converted into an electrical signal.
• The cone of a speaker. The cone is part of a speaker. In a microphone, sound waves make a thin diaphragm vibrate.
• It is very different from it. If all components work properly, the sound from the speaker closely matches the originally captured sound.
• It closely matches the sound that was captured — correct. Yes!
• It is silent. A speaker makes sound when an electrical signal makes its cone or diaphragm vibrate.