An attenuation of signal components resulting from combining out-of-phase waveforms. When two waveforms are mixed, their harmonics are added. If these signals are out-of-phaseout of phase with each other, the amplitudes of the harmonic components differ at various times, (as determined by the phase relationship.) If the added harmonics have the same polarity, the signal is reinforced at those frequencies, and vice-versa.
See phase distortion.