ATTENUATION, in radio communication, is the reduction in power of a wave or a current with increasing distance from the source of transmission. Attenuation of an electric current or wave is ordinarily the result of the absorption or loss of power in certain elements of the circuit or transmission path. In some electrical circuits, particularly for currents of audio-frequencies, it is possible to make substantially equal the total attenuation for all frequencies within a certain range. A device used for this purpose is called an attenuation equalizer.