Diagnostic Acceptability Measure (DAM) is a measurement method developed in the 1970s for assessing speech intelligibility
in communication systems. The DAM procedure involves the evaluation of speech quality in several independent diagnostic rating levels and the perceptual quality affected by background noise. The estimation of intelligibility, pleasantness and acceptability is done by direct assessment and several non-linear predictions of the rating levels. Extremely reliable results are obtained by the exact setting of the rating listeners.