There are abundant data which show the vocal folds to be abducted during closure for intervocalic /p,t,k/ in American English. Vocal‐fold abduction during such stops is reliably indicated by a rapid rise in intraoral pressure following oral occlusion. Recent recordings of intraoral pressure during an adult male English‐speaker's productions of labial and alveolar stops in a variety of environments suggest, however, that vocal‐fold abduction is characteristic only for voiceless stops which precede vowels. Synchronous recordings of intratracheal pressure showed during the closures of stops in all environments that the driving pressure for speech remained appreciably greater than atmosphere. But, during the closures for voiceless stops occurring initially in certain medial consonant clusters, and utterance finally, intraoral pressure generally did not rise above atmosphere. These facts together suggest that /p,t/ in these latter environments were voiceless by virtue of interruption of transglottal flow at the glottis. [Work supported by NSF grant BNS 77‐07686.]