Cue Primacy and Spontaneous Imitation: Is Imitation Phonetic or Phonological?

Abstract

Previous research on spontaneous imitation examines how speaker-listeners’ own production changes after hearing a few minutes of model speech, and suggests that speech perception and production are closely related. This dissertation investigates how cue primacy influences imitation by separately manipulating two co-varying cues differing in their primacy for one phonological category. By examining how similarly or differently primary and non- primary cues operate in spontaneous imitation, this dissertation studies the nature of the cognitive representations that are responsible for imitation. In order to examine whether the cognitive representations that are involved in speech imitation are abstract phonological categories or individual phonetic properties, this study tests spontaneous imitation of aspirated stops by Seoul Korean speakers. In Seoul Korean, at least two distinct acoustic properties, stop voice onset time (VOT) and post-stop fundamental frequency (f0), differentiate aspirated stops from stops of different phonation types, with post-stop f0 being the primary cue for aspirated stops. Seoul Korean participants heard and shadowed (i.e., immediately repeated what they heard without being told to imitate) target model speech in which initial aspirated /th/ was enhanced with either extended VOT or raised post-stop f0. Speakers’ realization of these properties in their own /th/, /t/, and /t*/ productions were compared before, during, and after exposure. The results show that enhancements of both primary and non-primary cues trigger imitative changes, and that exposure to an enhanced non-primary cue (long VOT) influences the production not only of that cue but also of the primary cue for aspirated stops (post-stop f0). However, an enhanced primary cue (high f0) does not have similar effects on the non-primary cue. Moreover, the imitative changes are generalized to maximize the relevant phonological contrast, as evidenced by lowering of f0 after lax /t/ and sonorants. These findings suggest that imitation is not strictly tied to individual phonetic properties but it is rather phonological in that abstract categories are involved in the process of imitation. This dissertation provides a new insight on the role of phonology in spontaneous imitation.