Rl. Plant et Rm. Younger, The interrelationship of subglottic air pressure, fundamental frequency, and vocal intensity during speech, J VOICE, 14(2), 2000, pp. 170-177
In this study we have simultaneously measured subglottic air pressure, airf
low and vocal intensity during speech in nine healthy subjects. Subglottic
air pressure was measured directly by puncture of the cricothyroid membrane
.. The results show that the interaction between these aerodynamic properti
es is much more complex that previously believed. Certain trends were seen
in most individuals, such as an increase in vocal intensity with increased
subglottic air pressure. However, there was considerable variability in the
overall aerodynamic properties between subjects and at different frequency
and intensity ranges. At certain frequencies several subjects were able to
generate significantly louder voices without a comparable increase in subg
lottic air pressure. We hypothesize that these increases in vocal efficienc
y are due to changes in vocal fold vibration properties. The relationship b
etween fundamental frequency and subglottic pressure was also noted to vary
depending on vocal intensity. Possible mechanisms for these behaviors are
discussed.