Independent acoustic features in speech perception
Dominic W. Massaro, Gregg C. Oden · The Journal of the Acoustical Society of America · 1977
Experimental and theoretical procedures are used to investigate how the various acoustic features of a speech signal are integrated into a synthesized percept. Stop consonant-vowel syllables were factorially generated by independently varying acoustic cues for voicing and for place of articulation and were presented to subjects for identification. The identification data for these stimuli were used to test a quantitative model which assumes that (1) the acoustic dues are perceived independently, (2) the feature evaluation stage provides information about the degree to which each quality is present in the speech sound, (3) each phoneme is defined by a prototype in long-term memory, and (4) the speech sound is identified on the basis of the relative degree to which it matches the various alternative prototypes. The present experiments replicate and extend previous work which has found evidence for shifts in the identification boundary of one acoustic dimension as a function of the level of another dimension. These results have been interpreted as evidence for the interaction of the perception of the acoustic features themselves. In contrast, the present model provides a good description of the data, while still maintaining complete noninteraction at the feature evaluation stage of processing.