In a system or device, any departure of the output signal waveform from that which should result from the input signal waveform's being operated on by the system's specified, i. E. , ideal, transfer function. Note: Distortion may result from many mechanisms. Examples include nonlinearities in the transfer function of an active device, such as a vacuum tube, transistor, or operational amplifier. Distortion may also be caused by a passive component such as a coaxial cable or optical fiber, or by inhomogeneities, reflections, etc. , in the propagation path. 2. In start-stop teletypewriter signaling, the shifting of the significant instants of the signal pulses from their proper positions relative to the beginning of the start pulse. Note: The magnitude of the distortion is expressed in percent of an ideal unit pulse length.