The simplest PA system consists of a microphone, an amplifier and one or more speakers. Whenever you have those three components, you have the potential for feedback. Feedback happens when the sound from the speakers makes it back into the microphone and is re-amplified and sent through the speakers again, like this:
Home SparkNotes â History Study Guides â The Great Depression (1920â1940) â The Roaring Twenties and the Jazz Age: 1920â1929.
The economy, technology and science. At the beginning of the roaring twenties, the United States was converting from a wartime to peacetime economy. When weapons for World War I were no longer needed, there was a temporary stall in the economy.