Could backward recognition masking play an important role in speech contrasts?

Abstract

Auditory backward recognition masking (BRM) is the interference in recognition by a following stimulus for some aspect of a clearly detectable target. BRM has been studied for stationary targets, with its conjectured relevance largely limited to the sensory storage and encoding of simple (nonspeech) auditory properties. Could BRM play an important role for more complex stimuli—specifically speech contrasts? The current study systematically investigates BRM interference for speechlike analogs of F2 transitions in varying spectral context that mimic the properties of speech contrasted by place of articulation. Initial and final transitions in isolation show equivalent recognition. Adding a vowel F2 equivalent significantly increases thresholds for initial, but not final, transitions. The further addition of a vowel F1 equivalent results in an additional significant increase in threshold for initial position transitions, and a significant decrease for final position transitions. The possible importance of BRM in defining speech contrasts is discussed. [Work supported by NSF.]