Per AES (Audio Engineering Society): Various definitions and measurements of phase distortion are reviewed beginning with first principles. Numerous representative examples are included, indicating quantitative amounts of phase distortion produced by microphones, loudspeakers, coaxial cables, antialias filters, and magnetic recording. The effects of phase distortion on time-domain performance are discussed. A frequency-dependent tolerance on group-delay distortion is developed based on seven different perceptual studies and compared with some representative measurements. New and complementary experiments are proposed to assess further the perceptual significance of phase distortion in music reproduction. Methods of phase equalization and phase equalizer design are presented. A new time-frequency display, showing both the location of a signal in time and its frequency spread, is introduced, which provides a more unified view of time-domain and frequency-domain interrelationships.
Preis, Douglas; 1982; Phase Distortion and Phase Equalization in Audio Signal Processing-A Tutorial Review; Tuffs University, Department of Electrical Engineering, Medford, MA; Paper ; Available from: https://aes2.org/publications/elibrary-page/?id=3810
