UC Berkeley UC Berkeley Phonology Lab Annual Reports Title Audio-visual Factors in Stop Debuccalization in Consonant Sequences Author Publication Date Audio-visual factors in stop debuccalization in consonant sequences
This study tested the hypothesis that some language sound patterns originate in factors relating to the perception of speech as an audiovisual signal. Specifically, this was a study of stop debuccalization (a process in which the place of articulation of a stop changes from oral to glottal). Phonetically trained listeners were asked to identify stop consonants in medial clusters as "p", "t", "k" or " ʔ" in audiovisual recordings of nonwords that had the test segments [p], [t], [k], and [ʔ] in
... , [k], and [ʔ] in syllable coda followed by [m], [n], [l] or [ŋ] in the onset of the next syllable. The relative timing of the audio and video streams were manipulated so that in 2/5 of the stimuli the audio was advanced relative to the video and in 2/5 of the stimuli the audio was delayed. This manipulation mainly affected the perception of [p] in homorganic [p.m] clusters such that when the audio was advanced listeners reported more "k" and "ʔ" than when the audio offset was unchanged or when the audio was delayed relative to the video. The implications of this type of effect in audiovisual speech perception on linguistic sound patterns is discussed.