A voice for the voiceless: Production and perception of assimilated stops in French

Previous studies, mainly conducted on English running speech, have reported that (place) assimilation between words is usually incomplete, and have suggested that the perceptual processing of word forms altered by that assimilation depends on the extent to which phonemes at word boundary have undergone assimilation. The present research provides an acoustic–phonetic description of regressive voice assimilation in French and proposes an objective measure of “voicing degree” for stops in word-final position. This measure is the relative duration of voicing within the stop closure. It is shown to closely correlate with perceptual judgments of voicedness. Across two experiments, we show that voice assimilation in French is graded and asymmetrical in that voiceless stops assimilate to a larger extent than voiced stops do. It also appears that assimilation is slightly modulated by lexical factors such as potential ambiguity and phonological neighborhood. If a word belongs to a minimal pair for final stop voicing (e.g., rate /rat/ ‘spleen’ minimally contrasts with rade /rad/ ‘harbor’), assimilation strength tends to be weaker. The same trend applies to a word challenged by ‘dangerous’ phonological neighbors that only differ from it by their word-final consonant.