15th International Congress of Phonetic Sciences (ICPhS-15)
For the first five vowel periods after aspirated/voiceless and unaspirated/voiced stops/fricatives in German the degree of glottal opening based on transillumination was measured simultaneously with the acoustic voice quality parameters H1-H2, H1-A1, H1-A3 (in order to capture breathy phonation and glottal leakage) and with F0. A gradual decrease in glottal opening and the voice quality values was observed after aspirated stops and voiceless fricatives, usually with an earlier-timed reduction in the case of the fricatives than the stops. Slight glottal opening and vq-value reductions were observed after unaspirated stops, probably resulting from aerodynamically-conditioned passive glottal opening. Higher vq-values were found after voiced fricatives than unaspirated stops. This is hypothesized to be a consequence of increased glottal leakage due to vocal fold slackening employed to maintain obstruent voicing, which in German is phonologically required for voiced fricatives such as /v/ but not for unaspirated stops such as /b/.
Bibliographic reference. Jessen, Michael (2003): "Acoustic correlates of glottal opening in German obstruent production", In ICPhS-15, 1695-1698.