Prediction of articulation scores

Abstract

Harvey Fletcher developed articulation theory to enable the prediction of the speech transmission capacity of imperfect communication systems, thereby eliminating the need for the time‐consuming speech recognition testing that is otherwise required to differentiate among systems. Two assumptions underlie the theory: (1) a speech signal in each of a number of contiguous frequency bands comprising the audible spectrum contributes independently to the articulation score (percent‐correct for lists of nonsense syllables); and (2) the separate contributions are additive. The approach of Fletcher and his colleagues was to define the articulation index, A, an entity for which these assumptions hold true. The equations for calculating A contain variables representing hearing acuity, critical bandwidth, masking, loudness, perception, and frequency importance weights so that the communication system’s frequency response and gain are translated into perceptual terms. In addition to the derivation of the theory, Fletc...