In Canadian French, besides periodic phonation, other cues can be associated with the voiced-voiceless distinction due to the application of phonological rules. These cues, mainly duration and vowel quality, may be present in the consonant itself (voiced consonants are shorter than their voiceless counterparts) and in the preceding vowels (duration and vowel quality). The cues are related to the application of an allophonic rule and the presence in the phoneme inventory of intrinsically long and short vowels. The tendancy towards devoicing of some portion of a normally voiced consonant in postvocalic word-final positions is found in many languages. This study investigates the patterns of devoicing in post-vocalic obtruants in Canadian French and attempts to verify the following functional hypothesis: a consonant will be more resistant to devoicing (absence of periodic structure) if no (or few) other cues of the voiced-voiceless distinction can be found either in the consonant itself or in the preceding vowel. The data will serve as a reference for current studies on patients with apraxia of speech.