Factors underlying short-term fundamental frequency variation during vocal onset and offset

Fundamental frequency (F0) typically decreases during vocal cycles immediately preceding and following voiceless obstruents for reasons that remain unclear. One explanation is that aerodynamic changes surrounding obstruent production underlie F0 variation. Alternatively, laryngeal maneuvers used to adduct/abduct the vocal folds may change vocal fold tension, leading to F0 variation. In this study, cycle-to-cycle variation in F0 was examined in several phonetic contexts that differ in aerodynamic and laryngeal factors. Results showed that at F0 onset, F0 variation depended more upon laryngeal factors than aerodynamic factors. At F0 offset, there were no significant differences across phonetic contexts. It is suggested that the factors influencing F0 variation at phonation onset may differ from those influencing F0 variation at phonation offset.