English stops after /s/ at medial word-boundary.
Subjects listened to a speech perception test. It consisted of a series of items obtained by tape splicing from one recorded English utterance it's still. The subjects assigned one of four possible English utterance choices to each item. Combined duration of the /s/ friction and closure of the following stop account for their choice between it's dill, it still or it's still. A delay in voice onset of the stop is primarily responsible for items consistently heard as it's till. There is no difference in closure duration between the traditionally fortis and lenis stops following the /s/.
D000162:Acoustics; D006801:Humans; D010700:Phonetics; D013060:Speech; D014705:Verbal Behavior