Spectral contrast in perception of VCV syllables

Abstract

The ability of listeners to recover speech information, despite dramatic articulatory and acoustic assimilation between phonetic units, is central to understanding perception of fluent speech. The present studies investigate the effect of preceding acoustic stimuli on identification of a series of synthetic CVs varying acoustically in F2 onset frequency and perceptually from /ba–da/. Results reveal that naturally produced /i/ and /u/ modulate identification responses to the CV series independent of speaker, suggesting that the effect of preceding V on CV identification is not critically dependent on precise matching of articulatory characteristics between V and CV. Moreover, nonspeech FM glides modeling F2 transitions of natural Vs shift CV identification in a similar manner, suggesting that quite general auditory mechanisms may contribute to observed shifts in CV identification. Further experiments reveal the effect of preceding V maintains for dichotic presentation and persists, but lessens, with intersyllabic silent intervals increasing to 200 ms. All results can be recast as cases of spectral contrast whereby spectral characteristics of preceding sound modulate perception of CV. These data suggest general auditory processes may play a substantive role in perceptual accommodation of coarticulated speech and provide clues to the nature of the putative auditory mechanisms. [Work suported by NSF.]