Reverberation Echo Density Psychoacoustics

A series of psychoacoustic experiments were carried out to explore the relationship between an objective measure of reverberation echo density, called the normalized echo density (NED), and subjective perception of the time-domain texture of reverberation. In one experiment, 25 subjects evaluated the dissimilarity of signals having static echo densities. The reported dissimilarities matched absolute NED differences with an R2 of 93%. In a 19-subject experiment, reverberation impulse responses having evolving echo densities were used. With an R2 of 90%, the absolute log ratio of the late field onset times matched reported dissimilarities between impulse responses. In a third experiment, subjects consistently reported breakpoints in echo pattern character at NEDs of 0.3 and 0.7.