glottal vibrato

[Robert Johnston <JOHNO@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

>Sometimes it seems to me like my throat vibrato is tending to
>actually stop the air flow for a miniscule time, as well as
>staggering the amount of air going through the harp.  This also
>produces some little extraneous throat noises through my JT-30.
>Can the glottis do the latter without any total momentary "shut off"?
>Is the guy who observed his glottis by sticking a TV camera down
>his nose out there to address this?

Indead Hank Bahnson did observe exacctly that. The Glottis opens and
closes with the vibrato.
But remember that the sub-glotal system ie. lungs wind pipe etc. are
also an acoustic resonator. So as the glottis opens and closes the
influence of this resonant system on the troat resonance also varies
with the vibrato. This means that the overall vocal tract resonance
is being modulated by the vibrato and therfore so is the playing
pitch.

Johno