Their limited range in volume was ineffective as symphonic music was impaired by excessive ground noise and amplitude distortion.
From the en.wikipedia.org
In AM radio, the intelligence is located in the amplitude variations, and distortion can occur due to spurious signals that could cause the baseband to be misrepresented.
From the en.wikipedia.org
In principle, PCM digital systems have the lowest level of nonlinear distortion at full signal amplitude.
From the en.wikipedia.org
The PFM monitors both the amplitude of this physical distortion and whether or not it is in or out-of phase with the applied voltage signal.
From the nature.com
A single FM signal is constant amplitude, so it can saturate a transponder without distortion.
From the en.wikipedia.org
The directions of tip distortion contributing to the amplitude images are given by the black arrows superposed onto the schematic cantilevers.