Doctor of Philosophy (Ph.D.), Bowling Green State University, 2017, Communication Disorders

Airflow vibrato is the fluctuation in average airflow while singing with vibrato. Understanding airflow vibrato relates to a deeper understanding of its importance to physiological, pedagogical, and clinical aspects. Two studies were performed to examine airflow vibrato. The subjects for Study 1 were four professional Western classical singers, and for Study 2 four highly trained amateur singers. Aerodynamic and acoustic measures were compared among vibrato, bleating (a primarily adductory gesture), and external epigastric pumping (EEP, a primarily subglottal pressure manipulation). Utterances included speaking (phonation and whisper) and singing (constant /a/ vowel, different pitches and loudness levels). Study 1 demonstrated how airflow vibrato compares with fundamental frequency (F0) and intensity vibrato. The correlation between rates of airflow and F0 vibrato was moderately strong. Mean airflow vibrato extents were larger for the female singers than for the male singers, and increased with pitch increase for all four singers. For the males, average airflow extent was 30 and 75 cm3/s for their lower and higher pitch, respectively, and for the females, 47 cm3/s and 94 cm3/s for their lower and higher pitch, respectively. Study 2 was undertaken to better understand sources of airflow vibrato. Airflow modulations were produced during singing with vibrato and also while bleating and with external epigastric pumping. Bleating had the fastest alteration rate (9.5-12 Hz), whereas the other types had similar rates (vibrato: 4.8-6.0 Hz; EEP: 6.0–7.5 Hz). During phonation (combining all conditions), bleating had the largest airflow modulation extents (on average 144 cm3/s, compared to 30 cm3/s for vibrato and 46 cm3/s for EEP). Overall results suggest that airflow vibrato typically leads F0 vibrato, and often has a more complex waveshape than F0 vibrato. Hypotheses generated from the study include: (1) A primarily subglottal pressure driven vibrato may provide relat (open full item for complete abstract)

Committee: Ronald Scherer Ph.D. (Advisor); Alexander Goberman Ph.D. (Committee Member); Jason Whitfield Ph.D. (Committee Member); Mingsheng Li Ph.D. (Other) Subjects: Health Sciences; Music; Speech Therapy

Master of Science (MS), Bowling Green State University, 2009, Communication Disorders

The purpose of this study was to describe the acoustic and aerodynamic characteristics of diatonic scale singing at different tempi in a professional female soprano. The classically trained singer sang ascending-descending ninth scales on /a/ in the F# major key at five different tempi – slow, moderately slow, moderately fast, fast, and fastest. All scales were performed with a moderate loudness level and with a pre-determined metronome marking. Tempo was controlled in order to determine whether differences existed between scales that were sung at a comfortable tempo and scales that were sung at an uncomfortable tempo. The slow (1 note = 104 beats / minute), moderately fast (2 notes = 92 beats / minute), and fastest (4 notes = 92 beats / minute) tempi were designated as comfortable because they were typically performed with integer multiple vibrato cycles per note. The moderately slow (2 notes = 72 beats / minute) and fast (4 notes = 69 beats / minute) tempi were designated as potentially uncomfortable because the note durations were not integer multiples of the singer's typical vibrato cycle period. There were a total of 5 ascending-descending scales analyzed in this study, one for each tempo. The results of the study strongly suggested trends in the acoustic and aerodynamic measures when tempo and scale direction were controlled. The following observations were noted: 1)mean fundamental frequency (F0) was higher in the descending notes than the corresponding ascending notes, 2)average F0 vibrato extent decreased as tempo increased, 3)mean note intensity was greatest at the highest notes and lowest at the lowest notes of the scale, 4)secondary intensity peaks were observed at the third (A#4) or fourth (B4) notes of both the ascending and descending portions of the scale, 5)airflow was greatest at the lowest notes of the scale and lowest at the highest notes of the scale, and 6)average airflow vibrato extent decreased as tempo increased. Distinctive trends were not (open full item for complete abstract)

Committee: Ronald Scherer PhD (Advisor); Jane Rodgers DMA (Committee Member); Laura Dilley PhD (Committee Member); Roger Colcord PhD (Committee Member) Subjects: Speech Therapy