F. Alipour et Rc. Scherer, Effects of oscillation of a mechanical hemilarynx model on mean transglottal pressures and flows, J ACOUST SO, 110(3), 2001, pp. 1562-1569
This study introduces a mechanical model of the larynx for investigating dy
namic aerodynamic effects of phonation. The model mimics the hemilarynx. Th
e tracheal inlet section was rectangular (25-mm width, 20-mm height). The v
ocal fold was fabricated with precision machinery from hard plastic with an
attached oscillating plunger. A speaker assembly and audio amplifier drove
the plunger, mimicking one-dimensional vocal-fold motion toward a flat wal
l. The glottal shape was rectangular. The glottal diameter was well specifi
ed or dynamically followed with a laser system. The air was sucked through
the channel using a vacuum with controlled speed. Frequency and amplitude o
f the glottis were varied. The mean pressure and mean flow data were record
ed. For steady-flow conditions, the glottal gap ranged from 0.39 to 2.58 mm
. The pressure coefficient for steady flow had a range of 3.1 to 1.3 for Re
ynolds numbers between 300 and 9000. For oscillation conditions (a) the fre
quency was varied from 75 to 150 Hz while the amplitude was held relatively
constant, and (b) the amplitude was varied to 0.3 mm for a fixed frequency
of 100 Hz. The results indicate that the hemilarynx model provides mean pr
essure-flow data similar in form to other models with two vocal folds. Furt
hermore, the dimensional and non-dimensional pressure coefficient is sensit
ive to variations in glottal gap and glottal amplitude, but relatively inse
nsitive to the frequency of oscillation. (C) 2001 Acoustical Society of Ame
rica.