Reported May 2005

Top: AM wave, Bottom: FM wave

WHAT ARE RADIO WAVES? We can't see them, but radio waves are all around us. Like visible light, they are a part of the electromagnetic spectrum, only with much longer wavelengths. Radio waves can be as long as a football field, or as short as a football. This range of sizes makes them ideal for sending information, because different frequencies can be assigned to specific devices to avoid overlap.

Radio works in much the same way as a telephone: sound waves are converted into an electrical current. But instead of traveling along a wire, the encoded sound data hitches a ride on a radio wave. It does this by changing either the wave's height -- also known as its amplitude -- or its frequency, which is the number of times the wave vibrates per second.

Think of the a regular radio wave as a blank sheet of white paper, and the radio wave with information on it as the ink that forms the printed words. The ink causes tiny variations in the background of the paper, and this is what the eye sees when it "reads". Mixing in a data stream of electrons causes the height or frequency of the wave to change slightly. These changes are detected by the receiver, which then decodes the information.

If you would like more information, please contact:

Fan-Gang Zeng, Ph.D.
Acoustics
Director of Hearing and Speech Lab
University of California at Irvine
Irvine, California
(949) 824-1539

fzeng@uci.edu

Tom Vasich
PAO
(949) 824-6455

tmvasich@uci.edu

Pop Quiz:

What rock star suffered severe hearing loss as a result of his close proximity to high decibels?

[Pete Townsend]

What classical composer went deaf and yet continued to compose?

[Ludwig von Beethoven]

What American inventor suffered hearing loss as a child after being boxed on his ears?

[Thomas Edison]

Did you know...

FM radio was invented by Edwin Armstrong, who built the first station in 1939. But FM didn't become popular until the 1960s.