Making Sounds

Many types of devices make sounds, for example:

“Manually” Making a Tone with a Piezo Buzzer

Piezo buzzers make sounds when the voltage across the buzzer changes; i.e., it
is not the level of the voltage over the buzzer that determines the frequency
or loudness of the sound they make, but the change in that voltage.

shows you how to make a sound just by “manually” turning a buzzer ON and OFF
in rapid succession.

Quick Method to Get Twice the Sound

Packet DoubleSound
shows you how to get twice the volume out of a piezo-buzzer with just a
simple change in the circuit and sketch.

Using the Arduino tone() Function to Create Sound

Packet Tone shows how to use the function tone() built into the Arduino
library to make tones on buzzers or speakers.

Connecting a Loudspeaker to an Arduino

While buzzers can often be activated using the current available through
an I/O pin of an Arduino, speakers often require much more power. There’s
a fix for that! The speakers packet shows how to control
a power-hungry device with an Arduino.