First International Conference on Spoken Language Processing (ICSLP 90)
The purpose of this study is twofold: (1) to examine respiratory controls when voice quality was specified, (2) to rate the relative efficiency of each of the voice qualities recorded. One female professional singer, who can consistently control six qualities was the subject of the experiment. Multiple repetitions were made of each quality at four fundamental frequencies: 192, 294, 392, and 587 Hz, as airflow, sound pressure levels, and electroglottographic measurements were recorded. In most of the qualities, air flow rate and acoustic intensity showed high correlation. Glottal efficiency, computed from these aerodynamic and acoustic measures, divided the six singing qualities into two groups: four loud qualities and two soft quantities. In the loud group, glottal efficiency increased with higher frequencies. The soft qualities, on the other hand, showed maximum efficiency in the middle frequency range.
Bibliographic reference. Estill, Jo / Kobayashi, Noriko / Honda, Kiyoshi / Kakita, Yuki (1990): "A study on respiratory and glottal controls in six western singing qualities: airflow and intensity measurement of professional singing", In ICSLP-1990, 169-172.